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Title: The geography and geology of south-eastern Egypt
Author: John Ball
Release date: June 20, 2024 [eBook #73879]
Language: English
Original publication: Cairo: Government Press, 1912
Credits: Galo Flordelis (This file was produced from images generously made available by The Internet Archive/Ohio State University Library)
*** START OF THE PROJECT GUTENBERG EBOOK THE GEOGRAPHY AND GEOLOGY OF SOUTH-EASTERN EGYPT ***
THE
=GEOGRAPHY AND GEOLOGY=
OF
=SOUTH-EASTERN EGYPT.=
PLATE I.
[Illustration: OROGRAPHICAL MAP OF SOUTH-EASTERN EGYPT.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
MINISTRY OF FINANCE.
* * * * *
SURVEY DEPARTMENT, EGYPT.
* * * * *
THE
GEOGRAPHY AND GEOLOGY
OF
SOUTH-EASTERN EGYPT.
BY
=JOHN BALL, Ph.D., D.SC.,=
F.G.S., A.R.S.M., M.INST.C.E.
[Decoration]
CAIRO:
GOVERNMENT PRESS.
* * * * *
To be obtained either directly or through any Bookseller, from the
PUBLICATIONS OFFICE, Government Press, Bulaq; from the SALE-ROOM,
Geological Museum, Ministry of Public Works Gardens; or from the
SURVEY DEPARTMENT, Gîza (Mudiria).
* * * * *
1912.
=PRICE 40 P.T.=
=PREFACE.=
* * * * *
This book is an attempt to give a systematic account of the geography
and geology of South-Eastern Egypt according to the latest information
available. It is based on surveys which I carried out by order of the
Egyptian Government during the four years 1905-1908, and has been
written in the intervals of other official work during the succeeding
three years.
In the first or introductory chapter, I have given a summary, with some
criticisms, of previous accounts of the region. This seemed advisable
in that the literature, although not very extensive, is scattered in
books and papers in various languages, and is not always easy of access.
The second chapter is a concise systematic account of the district,
designed mainly as a summary for those who do not wish to go into the
details; it also contains sections dealing with matters of insufficient
importance, or of which our knowledge is too scanty, to be treated of
specially in the succeeding chapters.
The third chapter is an account of the surveying methods employed and
the principal geographical results obtained. The surveying methods are
treated at some length, firstly because an adequate specification of
the survey methods used is necessary for the assessment of the value
of any contribution to modern geography, and, secondly, because some
of the methods are either new or little known, and have been found
by experience to be specially adapted to the mapping of this type
of country. The principal geographical results are given, mostly in
tabular form, as exhibiting clearly the groundwork of the actual maps,
and as indicating a series of adequately fixed positions which may be
employed as a basis in any further surveys.
In the fourth to sixth chapters the drainage lines and hill features
are systematically described. A knowledge of the drainage lines, as the
key to a precise understanding of the relief, is nowhere more important
than in these deserts.
In the seventh chapter the important question of water supplies is
considered, and the positions and particulars of the various water
sources are tabulated for easy reference.
The eighth to tenth chapters deal with the various rocks occurring
in the district. The petrology of the region has been discussed with
some fulness, because while the district offers a remarkable wealth of
rock-species, well exposed in considerable masses, detailed studies
of Egyptian petrology have hitherto been few. My great regret in this
connexion is that I have been unable to add chemical analyses of the
rocks.
The eleventh chapter summarises the general geological structure and
history of the region, as gathered from a broader outlook over the
detailed geological evidences.
In the twelfth chapter I have set down the information I was able to
obtain regarding the territorial limits of the different Bedouin tribes
inhabiting the region.
The thirteenth and concluding chapter of the book consists of brief
notes taken on the return march to Port Sudan.
In regard to the cartographic material, most of which is new, special
attention has been given to the place-names, and it is believed
that these are correct in almost every case. But as the names are
in languages not understood by European draughtsmen, it is almost
impossible that mistakes have been entirely avoided; in any case where
map and text may disagree in spelling (the differences will, I trust,
never be so great as to leave doubts of identity), the text should be
followed in preference to the map, as mistakes in the text are usually
more easily perceived and corrected. I would remark that although the
whole of the field maps have been employed in preparing the small scale
ones, yet the full detail can be recorded only on the large scale maps,
which are given for the most important districts; a future explorer
would do well, therefore, to refer to the manuscript field maps which
are filed at the Survey Office at Gîza, before concluding that no more
detailed survey exists than is shown on the maps in this book.
The plates illustrating the scenic types are from my own photographs,
while those illustrating the natural-size aspect of the typical rocks
are reproductions from water-colour drawings which I made from actual
specimens. These coloured plates of rocks are mainly designed to enable
prospectors to identify readily the ordinary kinds of stone they meet
with in the field; but they will also serve to give to petrologists an
idea of the appearance of hand specimens of rocks from this part of
the world, which are not frequently met with in the great museums. The
text figures of rock sections I have mostly drawn at the microscope on
silver prints from photographic plates, the prints being afterwards
bleached out with mercuric chloride; they will appear slightly
diagrammatic in places, owing to the necessity of using lines and dots
for tints, but I find I myself get a better idea of a rock from a
drawing of this kind than from a photograph.
Much detailed surveying of this mountainous and arid region remains yet
to be done, especially in the districts round the heads of the Wadi
Alaqi, before our knowledge of it can be considered complete. It is
hoped, however, that a substantial beginning has been made towards this
end, and that future work may be facilitated by the observational data
recorded in the following pages.
JOHN BALL.
CONTENTS.
* * * * *
PAGE.
CHAPTER I. — Introduction 1
„ II. — General Description of South-Eastern Egypt 18
„ III. — Surveying Methods and Principal Geographical
Results 39
„ IV. — The Wadis draining Westwards to the Nile 78
„ V. — The Wadis draining Eastwards to the Sea 94
„ VI. — The Mountains and Hills 164
„ VII. — Water Supplies 234
„ VIII. — Geology.—Sedimentary Rocks 251
„ IX. — Igneous Rocks 262
„ X. — Metamorphic Rocks 331
„ XI. — Tectonics and General Geology 354
„ XII. — Tribal Boundaries 366
„ XIII. — Notes on the Road from Halaib to Port
Sudan 372
INDEX 379
* * * * *
LIST OF PLATES.
* * * * *
Plate. To face page
I. — Orographical Map of South-Eastern Egypt FRONTISPIECE.
II. — Sketch Map showing Drainage Basins 22
III. — Sketch Map showing Water Sources and Roads 26
IV. — Views of Ruins at Um Eleiga and in Wadi 30
Shenshef
V. — Views of Tomb of Sheikh Shadli and Bir Shadli 32
VI. — Map of the District of Nugrus and Sikait 106
VII. — Summit Views of Gebels Nugrus and Abu Hamamid 166
VIII. — Views from Gebel Migif 168
IX. — Descending Gebel Zabara 170
X. — Views from the Summit of Gebel Atut 172
XI. — Views in Wadi Muelih and of Gebel Selaia 172
XII. — Typical Views among the Mountains of Hamata
and Abu Hamamid 176
XIII. — Views on Gebel Kahfa 178
XIV. — Views of Gebel Kalalat and the Summit of
Gebel Faraid 192
XV. — Map of the District of Abraq and Abu Saafa 202
XVI. — Panoramas from the Summits of Gebels Niqrub
and Gerf 206
XVII. — Map of the District of Gebel Gerf 210
XVIII. — Map of the District of Meisah and Wadi Di-ib 218
XIX. — Map of the District of Elba and Halaib 226
XX. — Geological Map of South-Eastern Egypt 250
XXI. — Geological Map of Ras Benas 258
XXII. — Acid Igneous Rocks 268
XXIII. — Intermediate Igneous Rocks 284
XXIV. — Basic and Ultra-basic Igneous Rocks 300
XXV. — Metamorphic Rocks 334
XXVI. — Sketch Map showing Tribal Boundaries 368
XXVII. — Sketch Map of Route from Halaib to Mohamed
Ghul 372
XXVIII. — Sketch Map of Route from Mohamed Ghul to
Port Sudan 372
LIST OF ILLUSTRATIONS IN THE TEXT.
* * * * *
FIG. PAGE.
1. Sketch-map showing position of area described 1
2. Map of Abraq Springs 123
3. View from the summit of Gebel Elba 229
4. Granite of Gebel Fereyid 269
5. Red pegmatitic granite of Wadi Gemal 271
6. Biotite-granite of Gebel Abu Hegilig 273
7. Hornblende-granite of Gebel Elba 275
8. Hornblende-granite of Gebel Hamata 275
9. Granite-porphyry of Kreishim Hill 276
10. Quartz-felsite of the Wadi Huluz 277
11. Quartz-felsite from a dyke at Gebel Kolaiqo 278
12. Altered quartz-felsite of Gebel Igli el Iswid 281
13. Microperthitic structure in felspar of quartz-felsite of
Gebel Hadarba 282
14. Fractured felspar crystals in crushed quartz-felsite of
Wadi Huluz 282
15. Syenite of Gebel Zergat Naam 284
16. Syenite-porphyry of Gebel Zergat Naam 284
17. Trachyte from a dyke at Gebel Kahfa 285
18. Diorite of Gebel Allawi 287
19. Diorite of Wadi Baaneit 287
20. Augite-diorite of Wadi Um Hargal 289
21. Augite-diorite of Gebel el Anbat 290
22. Mica-diorite from a dyke at Gebel Abu Hegilig 291
23. Diorite-porphyrite of Gebel Abu Hodeid 292
24. Augite-porphyrite of Wadi Muelih 293
25. Kersantite of Gebel Fereyid 294
26. View near the top of Gebel Sufra 296
27. Andesite of Gebel Sufra 296
28. Gabbro of Gebel Dahanib 298
29. Gabbro of Um Eleiga 299
30. Hypersthene-gabbro of Hadal Aweib Meisah 300
31. Olivine-gabbro of Gebel Um Bisilla 301
32. Olivine-gabbro of Gebel Atut 302
33. Olivine-gabbro from hill S.-E. of Gebel Selaia 303
34. Troctolite of Gebel Um Bisilla 304
35. Pyroxene-granulite of Kolmanab Hill 305
36. Diabase from under the Nubian sandstone, Rod el Nagi 306
37. Diabase from Gebel Abu Hamamid 308
38. Olivine-diabase from a dyke at the junction of Wadis Gemal
and Huluz 308
39. Diabase from a dyke in Wadi Kreiga 309
40. Mica-diabase of Gebel Um Khariga 310
41. Basalt of Gimeida Hill 311
42. Basalt of Einiwai Hill 312
43. Amphibolite from hills near Gebel Um Gunud 317
44. Amphibolite containing olivine and bronzite, Qrein Salama 319
45. Serpentine (probably from a mica-peridotite), east of Erf
el Fahid 321
46. Serpentine (from lherzolite), hills near Wadi Um Khariga 322
47. Serpentine (from dunite), low hills near Bir Abraq 326
48. Serpentine (from dunite), low hills near Bir Abraq 326
49. Serpentine (from wehrlite), Gebel Gerf 327
50. Bronzite passing into serpentine, Gebel Gerf 327
51. Serpentine (from harzburgite,), Gebel Korabkansi 329
52. Crushing of quartz and felspar in granite-gneiss, Gebel Um
Rasein 334
53. Diorite-gneiss, Wadi Muelih 334
54. Crushed and altered syenite (schist), near Gebel el Anbat 339
55. Hornblende schist, Wadi Muelih 340
56. Schist composed of crushed volcanic rocks, Gebel Abu Hamamid 341
57. Hornblende schist, near Gebel Eqrun 343
58. Emerald and quartz, near Sikait 345
59. Tourmaline in talc-schist, Sikait 346
60. Section of sandstone at Gebel Um Khafur 358
61. Junction of sandstone and granite, west of Gebel Um Reit 359
62. Faulting near Wadi Saalek 359
* * * * *
=THE GEOGRAPHY AND GEOLOGY OF
SOUTH-EASTERN EGYPT.=
* * * * *
CHAPTER I.
* * * * *
=INTRODUCTION.=
* * * * *
[Illustration: Fig. 1.—Sketch-Map of Egypt. The shaded area shows the
district treated of in this book.]
The district treated of in this volume constitutes the extreme
south-east corner of Egypt, lying between the parallels of 22° and
25° of north latitude, and between the meridian of 34° E. and
the Red Sea coast. It comprises an area of about 56,000 square
kilometres, and includes some of the most mountainous and least
accessible portions of the Khedive’s dominions.
The district has been comparatively little visited by travellers, and
the literature concerning it is not very extensive. Berenice (_Jh_)[1]
was founded by Ptolemy II (285-247 B.C.), who named the town after his
mother, as a station at one end of the road for transporting goods
from the Red Sea to the Nile at Koptos (Quft). The emerald mines in
the Zabara area were worked at least as early as Ptolemaic times,
and gold mines in the south at a much earlier date.
References to this part of Egypt occur in the writings of STRABO,
DIODORUS SICULUS, and PLINY, as well as in PTOLEMY’s Geography and
the ANTONINE ITINERARY. Both Strabo and Pliny state that in Berenice,
as in Syene, the sun cast no shadow at the summer solstice from
which they inferred the town to be on the tropic of Cancer, though
in reality it lay in their day some twenty-five kilometres, and is
now about 28′, or some fifty-two kilometres, north of the tropic,
the difference being caused by the secular change in the obliquity of
the ecliptic since the beginning of the Christian era. Ptolemy gives
the latitude of Berenice as 23° 50′, which is only 5′ too low;
the _Smaragdus mons_, or emerald mountain, he places in latitude 25°,
which is about 15′ higher than the true position of Gebel Zabara
(_Ec_). Diodorus gives a very clear description of the working of
gold mines in the Eastern Desert in his day, by miserable convict
labour. The road from Koptos to Berenice is mentioned, with lists of
stations and water reservoirs and their distances from each other,
both by Pliny and the writer of the Antonine Itinerary; and though
Pliny gives fewer stations than the Itinerary, the two accounts agree
very closely in estimating the total distance at about 258 Roman
miles, which, so far as can be judged from a partial identification
of the stations marking the route, is pretty correct. The island
of Zeberged (_Ok_), on which occurs the green gem called peridot,
is probably the _Topazos Insula_ of Diodorus, and the _Agathon_ of
Ptolemy; but Diodorus gives its length as eighty stades (about twelve
kilometres), which is three times greater than its present size, and
Ptolemy’s latitude of 23½° is some 16′ too low. Ptolemy states
that the coast was inhabited by the _Ichthyophages_, or fish-eaters,
while the _Troglodytes_, or cave-dwellers, of Strabo, were probably
the workers in the mines.
The books of the Arab geographers, EDRISI and ABU EL FEDA, contain
some references to the roads and mines of the Eastern Desert, but
their descriptions are unimportant and contain frequent palpable
errors.
D’ANVILLE, in his _Mémoires sur l’Egypte_, Paris, 1766,
pp. 230-235, attempted to construct a map of the coast of the Red Sea
by combining the classical records with some early Portuguese and
other charts, but the latter were too crude to enable any approach
to be made to an accurate map.
It has been thought that BRUCE discovered the island of Zeberged
and the emerald mines of Zabara in 1769, but it is tolerably certain
that he saw neither of these places. He estimated the latitude of the
island he saw “pretty exactly” as 25° 3′, and its distance from
the coast as three miles,[2] whereas Zeberged is really in latitude
23° 36′, and is over thirty miles from the nearest coast. The
mines he saw were so close to the coast that he could walk to them
from his boat and back in less than a day (in fact he states that
they were only three miles from the coast), while both the Sikait
and the Zabara mines are over a day’s journey from the sea. Nor
could the mines have been the sulphur workings near El Ranga (_He_),
unless Bruce made a large error in his observation for latitude, for
the sulphur mines are about in latitude 24° 25′, and, moreover,
Bruce states that he found “brittle green crystals,” not sulphur.
It is to the French traveller CAILLIAUD[3] that we owe the first
modern account of Berenice and the emerald mines. Cailliaud was a
mineralogist, in favour with Mohammad Ali Pasha, who sent him on
two expeditions in 1816 and 1817 to search for mines in the Eastern
Desert. On his first expedition, starting from Redesia (near Edfu),
he discovered the rock temple of Seti I, forty-five kilometres
east of the Nile, and several ancient stations on his route, and
proceeded to the emerald mines of Zabara and the sulphur mines of
El Ranga. On his second expedition he took with him sixty Albanian
workmen to exploit the mines, and led them by nearly his former
route to Zabara, where they extracted ten lbs. weight of emeralds
(beryls) for presentation to the Pasha. On this second expedition
Cailliaud discovered the mines and ruins of Sikait, and also other
ruins in the Wadi Nugrus (_Ed_). Cailliaud’s drawings of the ruins
of Sikait greatly exaggerate their size and elegance.
JOMARD, in notes prefaced to Cailliaud’s account of his travels,
made a careful study of the probable positions of the ancient roads
and mines in this part of Egypt; he thought that Wadi Gemal Island
(_Hd_) was Zeberged.
In 1818, BELZONI,[4] fired by Cailliaud’s discoveries, set out
to discover the ancient Berenice. Starting from Edfu, he travelled
eastward for some days over Cailliaud’s route, then marched _via_
Bir Samut (where he discovered the ancient station) and Wadi Ghuel
to the Zabara mines, where he found Cailliaud’s miners still at
work. From Zabara he journeyed through the Wadi Sikait, passing the
mines and ruined temples which had been discovered by Cailliaud,
and down the Wadi Gemal to the sea. Proceeding then southward
along the coast, he examined the sulphur mines at El Ranga near
the mouth of the Wadi Abu Ghusun, and then made his discovery of
the ruins of the temple and town of Berenice, near the peninsula of
“Cape Galahen” (Ras Benas). The ruins were so inconspicuous as
to be only found with difficulty, and the temple was so buried in
sand that Belzoni could only make a very imperfect plan of it. The
ancient town he estimates to have covered a space near the temple
1,600 feet broad and 2,000 feet long. Leaving Berenice the same
day on which he made his discovery, Belzoni returned to Sikait by
way of Abu Greia, Haratreit (where he discovered ancient stations),
Hefeiri well, and the spring of Um Sueh. After copying some Greek
inscriptions at Sikait, he returned to Edfu by way of Wadis Hafafit
(_Dc_), where he found an ancient station, Abu Had, and Samut.
Belzoni’s map[5] of his routes is of course very crude and
erroneous, but the fact that he gives the names of the places he
passed enables one to reconstruct his routes on modern maps with fair
exactitude. His drawings of the ruins he visited are fairly accurate,
that of the rock temple of Sikait being a much truer picture than
Cailliaud’s.
The extreme south-east corner of Egypt was first explored in 1831
and 1832 by LINANT DE BELLEFONDS, who twenty years later published an
interesting account of his travels and discoveries.[6] The manner in
which Linant Bey’s expedition arose is very curious. He had read
the accounts of Diodorus and Arabic writers concerning the ancient
gold mines of the Eastern Desert, and when he accidentally discovered
small crystals of gold in quartzose detritus brought down the Wadi
Alaqi into the Nile by a storm torrent, he at once inferred that
this wadi would lead him to the mines. The Arabs told him, quite
correctly, that the down-wash had its origin far up the wadi, nine
days’ journey from its mouth. Reporting his discovery to Mohammad
Ali Pasha, that prince commissioned him to lead an expedition to
search for the mines. Starting from Aswan, Linant journeyed south-east
and discovered the ancient mines and ruins at Gebel Seiga (_Bp_), and
subsequently the more extensive workings at various places round the
head of Wadi Alaqi, such as Egat (_Ft_) and Darahib (_Gu_). From the
Alaqi district he proceeded northward to Bir Shinai (_Hr_), and thence
eastwards round the spurs of the mountains to Bir Meisah (_Kr_),
east of which he discovered the old mines of Romit (_Ls_). Crossing
the great Wadi Di-ib, he appears to have reached Bir Akwamtra (_Os_),
at the foot of Gebel Elba. His desire to explore the mysterious Elba
mountains was frustrated by the Arabs, and he only ascended a minor
peak before commencing his return march. From Elba he returned _via_
Bir Meisah, Bir Beida (_Ho_), and the Wadis Khashab (_Gn_), Hodein,
Rod el Kharuf (_Ch_), and Kharit to Daraw on the Nile, discovering
the springs of Abu Saafa (_Em_) in the course of his march.
Linant thus performed for the south portion of the district a similar
service to that which his compatriot Cailliaud had already done for
the north portion. His remarks on the people of the country, their
manners and customs, are no less interesting than his descriptions of
the ruins and mines which he discovered. The notes on certain points,
such as the manner of trapping the wild ass which then roamed these
deserts, are specially interesting as illustrating past usages. Linant
also compiled a small Bisharin-French vocabulary as an appendix to
his work. The large map accompanying his book, though it is well
engraved and depicts well the general mountainous character of the
country, is unfortunately full of large errors; Gebel Is (_Jt_), for
example, is placed more than sixty kilometres too far south; while
many of the place-names are either wholly incorrect or so loosely
transliterated as to be almost unrecognisable. But with all its
defects, Linant’s map remained the only source for cartographers
for a large portion of the Eastern Desert down to the time of the
commencement of the present survey; the map of Egypt published in
1905 by the Topographical Section of the British General Staff, for
instance, contains much of Linant’s material, though a comparison
of that map with the one joined to this report will show how great
were the errors in the matter thus incorporated.
WILKINSON[7] gives very brief notes on Berenice and the ancient roads
leading to it, as well as on the emerald mines of Zabara and the
ruins of the Sikait district. Wilkinson believed he had identified
all the ancient stations on the Koptos-Berenice road, besides another
smaller one not mentioned in classical itineraries. In the temple
of Berenice he found a small fountain, which is now in the British
Museum. But his work added little to what had already been learned
by Cailliaud and Belzoni regarding this part of Egypt.
In 1836, WELLSTED,[8] a lieutenant in the Indian Navy, who had been
employed in surveying the Red Sea coast, described the topography
of Berenice, and assigned to the place its true latitude of 23°
55′. He gives a plan and view of the temple, which he partially
cleared, and in which he found fragments of Greek tablets and of
a statue.
Between 1830 and 1840 important contributions were furnished to the
geography of Eastern Egypt by the surveys of the Red Sea, carried out
by MORESBY, WELLSTED, and other officers of the East India Company’s
Navy. Their sailing directions formed the foundation of the “Red Sea
and Gulf of Aden Pilot,” now published by the British Admiralty.[9]
Both the charts and sailing directions have been continually revised
by Admiralty surveys, and furnish much accurate information about the
coast. The principal errors are that almost the entire coast-line
between latitudes 22° and 25° is placed too far to the west,[10]
and some of the place-names are wrong, or at least unknown to the
local sailors of to-day. Such details of the inland relief as are
given on the charts are not correct, as was of course to be expected
in a hydrographic survey; but the main summits are fairly accurately
laid down, and their altitudes agree well with my determinations. Thus
the “Southern peak” of the chart, in latitude 23° 18′, is
Gebel Fereyid;[11] the “Black conical hill,” near Mersa Shab,
is Gemeida; “Scragged hill” is Qash Amir;[12] “High peak”
is Gebel Elba; “Castle hill” is Gebel Shendodai; and “South
peak” is Asotriba, the highest mountain of the Elba group.
In 1846, BARTH made a journey from Aswân to Berenice and thence
to Qoseir, and subsequently published a brief journal of his
expedition.[13] Going eastward from Aswân, he passed north of
Gebel Hamrat Mukbud (_Cf_), _via_ the Wadi Khashab, past the tomb of
Sheikh Shadli (_Df_) and the granite boss of Selaia (_Fh_), which
he thought to be of slate, and then descended to the coast by Wadi
Salib Abiad and Wadi Khoda (_Hf_). He discovered the old station
(now called Garia Kalalat) south-west of Berenice, on his way to the
temple, of which he took measures. Barth remarks on the insignificant
nature of the ruins and on the badness of the site for a town. On his
return journey, he discovered the wells and ruins of Shenshef (_Jj_),
where there are well preserved remains of substantial dwellings which
he thought denoted a settlement by people from Berenice. Ascending
the Wadi Shut after returning to Wadi Khoda, he turned westward and
reached the plain south of the Abu Hamamid-Hamata mountains. Crossing
this mountain track by the difficult pass of Hilgit, he descended
the Wadi Huluz (_Ef_), into Wadi Gemal, whence he turned northward
and visited the ruins of Sikait. From Sikait he proceeded by winding
tracks past Bir Ghadir (_Ec_) and on to Qoseir.
The next traveller to visit the district, VON HEUGLIN, examined
the country from the coast.[14] Sailing southward from Qoseir,
he discovered ruins which he thought to be those of Ptolemy’s
_Nechesia_, in latitude 24° 55′, a little south of Ras
Tundeba. Further south, he enumerates the various openings and
anchorages of the coast to Suakin. Gebel Hamata (_Gf_) he wrongly
thought might be the Alaqi of the ancient mining records. His
“Wadi el Hemmah” is doubtless Wadi Lahami (_Hg_). Rounding
Ras Benas, he passed the coral island of Mukawar (Geziret el Ras),
and anchored by the ruins of Berenice, which he states to be called
Sikait Qibli.[15] In and near the temple ruins von Heuglin found
copper nails, fragments of statues, Roman coins, a quartz sistrum and
pieces of beryl, besides potsherds and broken glass. Passing Mersa
Shab (Sherm Hel el Madfa), he notes a few fishermen’s dwellings on
Seyal Island, and a pearl fisher from Jidda plying his calling at
a small anchorage called Gota, near Ras Fatma. He mentions Kwolala
as “Geziret Elba,” close to the “peninsula of Halaib” (now
an island, Geziret Halaib).[16] The Elba mountains he states to be
the _Prionotus mons_ of Ptolemy. The “Sherm Qubeten,” which he
notes to the south of Halaib, is doubtless Mersa Qabatit of my map.
It is to the veteran African traveller SCHWEINFURTH that we owe
the first investigations of the Elba mountains, as long surrounded
with mystery as the stronghold of dreaded Bisharin tribes.[17]
Like von Heuglin, Schweinfurth visited the country from the
coast, making excursions inland. Starting from Qoseir in March,
1864, he proceeded with frequent stoppages to Suakin, spending
nearly six months in exploring the littoral districts. His chief
object was the investigation of the flora of the country, but his
accounts[18] contain much geographical and geological information
of great interest. He compares the coastal ranges of Africa with
the Cordilleras of South America, and the Abyssinian highlands with
Quito. The flora of the Elba district he found to be sharply marked
off from that of the rest of Egypt by the presence of large numbers
of plants of Abyssinian types. Among his geological notes, it is
interesting to come across a reference to serpentine, which I have
lately found to form the great mountain masses of Abu Dahr (_Gk_),
Korabkansi (_Fq_), and Gerf (_Hp_). Schweinfurth wrote, however, in
the early days of petrography, and his term “basalts” includes a
variety of fine-grained dark eruptive rocks which we should now call
by other names. The sulphur mines of El Ranga he characterised as
worthless, the mineral being in very small quantity. Schweinfurth’s
map of the Elba district was a great advance on anything of the
kind previously existing, though it contains many inaccuracies,
particularly of place-names, as was in fact only to be expected from
his very short stay in the locality. He remarked the separation
of Gebel Elba (_Pr_) from the more southern mountains, but failed
to notice that Qash Amir (_Os_), (the “Scragged Hill” of the
Admiralty Chart), is in its turn quite distinct from Elba, Halaib
is called Elei,[19] and the Geziret Halaib is shown as a peninsula;
Kwolala is called “Geziret Elei,” and the Geziret el Dibia
(the Elba Island of the charts) is called Geziret Abu Fendira by
Schweinfurth. My Wadi Shellal he calls “Wadi Heberah,” and Cape
Elba (my Ras Hadarba) is noted as “Ras Edineb.” His “highest
peak” (South Peak of the charts) is Asotriba, the highest mountain
of the group, lying just within the Sudan; the name Asotriba
(Schweinfurth’s “Soturba”) means “green mountain,” and
refers to the vegetation on its slopes. Schweinfurth’s experience
of the Bisharin led him to give them a very bad character, though
he gives high recognition to their beauty of feature and figure;
but being unfamiliar with their language was, he admits, an obstacle
to forming a fair judgment of them.
In 1873, Colonels PURDY and COLSTON, two American officers attached
to the Egyptian Army, were commissioned by the Khedive Ismail Pasha
to carry out a reconnaissance for a proposed railway line between
Berenice and Berber. Colston[20] travelled overland from Qena _via_
Qoseir to Berenice, discovering several ancient stations on his
way to join Purdy. Though Purdy sanguinely states[21] that “la
construction d’un chemin de fer de ce point (Berenice) à Berber
n’offrirait pas de grandes difficultés,” the reconnaissance
appears to have been singularly rough for a decision in so weighty a
matter. Distances were mere guesses, and the only instruments employed
seem to have been a compass, aneroid, and hypsometer. The compass
must often have been unreliable owing to magnetic rocks, which in
places deflect the needle as much as 40° from its normal position,
while the use of the aneroid was so little understood that Purdy
could actually write, in the concluding paragraph of his paper: “Je
me permets de rappeler l’attention sur les notes barométriques
jointes à ce rapport. A ce propos, je dois faire observer que
quoique l’anéroïde soit très sensible aux changements de
niveau, il ne l’est pas assez pour la pression atmosphérique,
et sa marche est excessivement irrégulière. . . . Il m’est
arrivé, par exemple, de constater, le matin, au moment du départ,
une différence sensible du point marqué le soir précédent à
mon arrivée.” Not only are many of the place-names given by Purdy
erroneous, but some of his most important statements are contrary to
fact; to take only a few examples, the Wadi Kalalat is confused with
Wadi Shenshef, and Gebel Shut with Gebel Dahanib, while it is stated
that no water exists between Gebel Dif (_Fm_) and Gebel Egat (_Ft_),
although there are several good wells between the two places. The
map accompanying Purdy’s paper is full of errors, and almost
worse than useless. Of Colston’s route from Qena to Berenice there
was no published cartographic record until 1891, when G. CORA[22]
endeavoured to place Colston’s track on a map from his manuscript
sketches. Cora’s map shows no new material except the route, and
even this cannot be very correct, for it is evident on comparison
with the results of the recent survey that Colston’s sketch map
was of the same rough and inaccurate character as Purdy’s.
In January 1889, GOLÉNISCHEFF made an expedition from the Nile
to Berenice and back. His object was to collect archæological
information, especially concerning the ancient roads and stations, but
the careful account[23] which he has given of his journey is also of
geographical interest. Starting from Redesia by Cailliaud’s route,
he examined the temple of Seti I, and then discovered the ancient
station of Abu Medrik[24] further to the south-east. Passing the
ruins at Samut and Dweig (_Cc_), he found another small station on
the way to Abu Had, and arrived at the station in Wadi Gemal (_Ed_),
near Wadi Hafafit. From the Wadi Gemal he proceeded _via_ the Wadis
Abiad (_Fe_), Abu Hegilig, Hefeiri, Abu Ghusun (_Ge_), Haratreit
(_Hf_), Khashir (in which another ancient station was discovered),
and Lahami (_Hg_), past the Abu Greia ruins, to Berenice. He returned
by way of Wadis Naait (_Hh_) and Lahami on to the plain of Kharit,
and thence past Hamrat Mukbud (_Cf_), _via_ the Wadis Khashab, Kharit
(_Ag_), and Abu Modellim, to the Nile. Golénischeff, besides giving
small plans of the various ancient stations and a carefully measured
plan of the temple of Berenice, made a comparison of his itinerary
with the descriptions of the old roads by classical writers and
by Colston. He considers there can be no doubt that Abu Greia is
the _Vetus hydreuma_ of Pliny, and the ruins in Wadi Khashir the
_Novum hydreuma_ of the same writer. The ruins in Wadi Haratreit he
considers to be the station _Cabalsi_ of the Antonine Itinerary,
_Apollonus_ being identified with the well found by Colston at
Hefeiri, _Falacro_ with the ruins in the Wadi Gemal, and _Aristonis_
with those in Wadi Dweig.
In 1891, FLOYER, at the head of a scientific exploring expedition sent
out by the Khedive Tewfik Pasha, travelled over the country north of
23° 30′, and his results were published in French in 1893.[25] A
little later, the geographical results of the expedition were embodied
in an English paper read at the Royal Geographical Society.[26] The
general map in the French essay is only on a very small scale, but the
English publication is accompanied by a much more illuminating map on
a scale of 1:760,320, reduced from one prepared by the Intelligence
Division of the War Office from Floyer’s original plane-table
sketches. This latter map, in spite of many errors and defects, was a
very great advance on anything which had previously appeared, and it
formed the principal source of geographical information concerning the
north part of the district at the commencement of my survey in 1905.
The geological observations made by Floyer during his expedition
formed the subject of a paper read by him before the Geological
Society of London in 1892.[27] This paper is chiefly remarkable for
the number of grave errors of observation into which Floyer’s
limited acquaintance with geology caused him to fall, and later
researches have fully justified the scepticism with which his
deductions were received by the Society. Thus, for instance, he refers
to the ancient schists and slates of Zabara as “blue clay,”[28]
and to the dark schists and diorite of Abu Hamamid and Abu Gurdi
as “compact granite.” The rocks which Floyer considered to be
“metamorphosed sandstone” are diorites and schists at Um Eleiga
and in the Wadi Gemal, and typical gneisses and granites in the Nugrus
and Hafafit ranges. Not a trace of sandstone has been found to exist
within many miles of the places where Floyer records its metamorphism,
nor has any evidence of the recent volcanic activity reported by him
(_Geog. Journal_, 1893, p. 430) been discovered.
An account of a short visit to the Elba district was published
by BENT[29] in 1896. Bent landed at Halaib and camped near Gebel
Shellal (_Qt_). He thinks that Halaib may have been the town of
_Aydat_ mentioned by the Arab geographers Abu el Feda and Edrisi,
and that it is a place of purely Arab origin. At Suakin el Qadim
(_Qs_) he found among the mounds nothing earlier than Cufic remains,
unless certain graves, formed of four large blocks of coral set
deep in the ground, may be looked upon as a more ancient form of
sepulture. His “Gebel Shendeh” should be correctly Gebel Shendib,
and his “Shendoeh” is correctly Shendodai; the “Riadh”
mentioned by him I have not been able to identify. His estimated
heights are considerably in error; thus Gebel Shendib is really
6,273 feet and Gebel Shellal 4,623 feet instead of the 4,500 feet and
4,100 feet which he gives. The paper contains interesting remarks on
the Hamedorab tribe, which Bent was informed totalled only some 300
fighting men in the entire district from Asotriba to Ras Benas. The
reference to the sheikh as “the batran” is due to a misconception;
Batran was the late sheikh’s first name, and is not a title of
station. The map accompanying Bent’s paper is only to a very small
scale, and formed practically no addition to existing knowledge.
MACALISTER[30] has given a detailed and interesting account of the
Sikait district (_Ed_), with special reference to its geology, as
the result of an expedition there in 1899. The small scale sketch
map of the route followed in reaching the mines from the valley is
not very correct, but the detail maps of the Sikait neighbourhood
give an accurate representation of the area in which the mines
are situated, while the geological notes give an excellent idea
of one of the most highly metamorphic areas of the entire Eastern
Desert. Macalister gives some notes also on the ruins and the people
of the neighbourhood. His experience of the Ababda as workers was very
unfavourable; though his characterisation is unfortunately only too
well merited by a large section of the tribe, it is probable that a
longer acquaintance with Arabs would have enabled him to select men of
a better class. A sufficiency of good men for a caravan of 130 camels
cannot be raised without great expenditure of time and care, even by
those who have lived for many years among the Arabs, and a few bad
characters in a desert camp soon exert a bad influence over the rest.
The brilliant series of investigations carried out by the officers
accompanying the Austrian research ship “POLA” in the Red Sea in
the winter of 1895-96, though chiefly concerned with oceanographic
questions, contain not a few observations of interest connected with
the land.[31] The positions determined include Sherm Sheikh, Berenice,
St. John’s or Zeberged Island, and Halaib. The latitudes observed
agree well with the values which I found by triangulation.[32]
For longitude the method used was the transport of chronometers,
and this method is liable to such considerable errors that we
need have no hesitation in preferring my triangulation values,
especially as our latitudes are in agreement. The observations
made by the officers of the “Pola” on the compass-variation at
Berenice and Halaib are of considerable importance as enabling us,
by comparison with my own observations at the same places, eleven
and twelve years later, to obtain a reliable value for the rate of
secular change of this magnetic element in the district. A large
scale map of Halaib is given, and amongst other observations of
interest to the geographer in South-Eastern Egypt are analyses of
the water at Halaib, a series of pendulum observations which show
a decided increase in the force of gravity over the sea as compared
with the intensity over the land, and descriptions with figures of
some of the reptiles which are found in the region.
Turning now to the work of the GEOLOGICAL SURVEY in the district,
the maps and descriptions in the present volume are the result of
surveys carried out by me in the three seasons 1905-1908, or about
twenty-two months’ work in all. The survey was commenced primarily
with the view of enabling mining concessions to be accurately marked
out. How little possibility of this existed so recently as 1902 may
be gathered from the fact that although a ministerial order of that
year had defined the administrative frontier between Egypt and the
Sudan as being a line joining certain important mountains and wells,
which were named, yet it was impossible to lay this frontier down
correctly on a map because the geographical positions even of these
important features were uncertain to many kilometres.
The main interest in the field methods used, which will be described
in detail in a subsequent chapter, lies in the fact that many of
them are wholly or in part new, having been devised as the work
proceeded to meet the special exigencies of the case. The costly
nature of camel-transport, and the relatively small value of
the country, precluded the employment of the ordinary sequence of
survey operations, and it was necessary to carry on reconnaissance,
precise triangulation, detailed topographical mapping, and geological
surveying, all at once, and to move rapidly so as to cover a large
area in a moderate time. Starting from a measured base near Gebel
Muelih, which had been previously connected by triangulation with
the Nile Valley, a network of large triangles was thrown over
the country. The essential feature of the triangulation was the
employment of observations at relatively few occupied main summits,
to fix large numbers of points by intersection; in some cases over
a hundred triangulation points were sighted from a single occupied
station. The triangulation was continued so as to join to a second
base line near Gebel Um Harba (_Ck_), and was also connected on to
main points in the trigonometrical survey of the Sudan, thus linking
up a continuous chain of triangles from Alexandria to Berber. The
total number of main (occupied) stations was sixty-four, while the
intersected points numbered 450. In addition to these, about 1,200
minor points were fixed by subsidiary triangulation from short
local bases.
Levels were taken trigonometrically for all points fixed by
triangulation, using the actual sea-level as the datum. The altitudes
of nearly all camps were likewise found trigonometrically, and
between successive camps aneroid readings, adjusted to the initial
and terminal points of the day’s march, were employed to supplement
trigonometrical determinations made on the journey.
For the control of the maps, latitudes and azimuths were taken at
intervals, the former by equal altitudes of three or more stars,
the latter by elongations of close circumpolar stars.
The topographical sketching, carried out on plane-tables on a scale
of 1:100,000, was based on the points triangulated, these being
computed in camp and plotted by their geographical coordinates
as much ahead of the lines of march as possible. When marching,
plane-table stations were fixed by re-section from three or more
triangulated points, the compass being useless owing to abundance
of magnetic rocks. Details along the line of march were put in by
tacheometric readings from the stations, using specially devised
long distance methods. But the greater portion of the sketching was
done from the mountain tops while occupying them as trigonometrical
stations, and for this again special methods, involving an extensive
use of vertical angles, were employed. On an average, about thirty
square kilometres were sketched in during each day’s march, and
about 400 square kilometres from each main trigonometrical station,
where it was usually necessary to remain for at least a week to get
sufficiently clear weather for the more distant sights. It was not,
of course, possible to sketch every portion of the area in uniform
detail, for some parts lay so far from the line of march and from
the triangulation stations that little or no detail was visible. The
lacunæ were filled in as far as possible in the field from guides’
statements, taking care on the field maps to distinguish parts so
filled as only approximate. A few additions near the west limit
of the map have been added from reconnaissance surveys by various
colleagues of the Survey Department. For details of the upper part of
the basin of the Wadi Alaqi, I have taken advantage of an admirable
reconnaissance-survey of this tract recently made by Mr. J. MORROW
CAMPBELL, B.SC., F.R.G.S., for the Egyptian Options, Ltd., who
kindly placed their map at the disposal of the Government. My
triangulation gave the positions and altitudes of all the principal
peaks of this region, and thus enabled Mr. Campbell’s map to
be accurately adjusted to the Survey positions, and his drainage
lines and other topographical details have been inserted with great
advantage to the map, which would otherwise have been almost blank in
this particular area. Mr. Campbell’s map does not, unfortunately,
give any altitudes, and the only altitude data for the orographical
sketching were the peaks and other points of connexion with the Survey
map; but by taking into account the depth of shading of the different
hill masses and the known altitudes determined by triangulation,
it is believed that a fairly approximate picture of the orography
has been obtained.
The sea coast north of latitude 24° 10′ was adapted from the
Admiralty Chart, fitting it on to coast points trigonometrically
fixed. South of 24° 10′ the coast was surveyed in detail by means
of depression angles from the occupied peaks of the triangulation. The
local circumstances, in the existence of high mountains pretty
close to the sea, are so favourable to the employment of this
method, that it is confidently believed that the maps represent
a considerable advance in accuracy over the Admiralty Charts. It
was frequently possible to check the accuracy of the coast-line
delineation by plane-table rays, and it was invariably found that
the errors were insensible, even on the fairly large scale employed
in the field-maps. The coast-line shown is the high water-line. The
tidal change of level, though it is generally less than a metre,
uncovers in many places extensive coral reefs at low water, but no
attempt was made to map these.
Very special care was taken with place-names, which are transliterated
on the Egyptian Government system. It may be remarked that this system
is based on the Arabic _spelling_, not on pronunciation. Thus, in this
part of the country, the letter _g_ is almost always soft, like an
English _j_, and the _q_ is always sounded like a hard _g_. The same
system was used for the Bishari and Ababda names, these being first
written by a guide in Arabic characters and then transliterated. It
is believed that the orthography is correct in almost all cases.
The geology was examined along every line of march, and additional
specimens were obtained by sending guides to collect rocks from
mountains otherwise unvisited. Where possible, the principal
geological boundaries were drawn direct on the plane-table sheets in
the field, and the remainder have been placed from field notes. The
limits of the different igneous and metamorphic rocks shown on
the geological map aim only at showing general relationships,
for in many cases it is difficult, owing to insensible gradations,
to decide exactly where granites and diorites end and gneisses and
schists begin, while in other places rocks of two or three distinct
species are so intimately mixed that the boundaries could not be
shown on the small scale used, even if the exact limits were traced
by a life-time’s work; in these latter cases the areas are coloured
in accordance with what appeared to be the dominant rock within them.
Throughout the three seasons’ work I was accompanied by Dahab
Effendi Hassan, who rendered useful assistance in booking angles and
in reconnaissance, and in the third season Mr. O. N. Bakewell also
accompanied me and gave me much useful help. The Egyptian unskilled
staff employed consisted almost entirely of Bedouin and comprised on
an average about twenty-five camel drivers (for thiry-five baggage
camels), six porters, three guides, and two postmen, all placed
under an Arab sheikh.
The total cost of the field-work was approximately L.E. 5,090, or
about 150 milliemes for each square kilometre of country mapped
in detail. Nearly two-thirds of the entire amount were expended
in camel-transport, the remainder representing the expenditure on
salaries and allowances of the author and assistants engaged in
actual surveying operations.
* * * * *
[Footnote 1: The references in parentheses after place-names refer
to their positions on the map, Plate I.]
[Footnote 2: _Bruce’s Travels to discover the Sources of the Nile._
Halifax, 1845. pp. 78-80.]
[Footnote 3: CAILLIAUD, _Travels in the Oasis of Thebes and in the
Deserts east and west of the Thebaid_, edited by JOMARD. Translated
from the French. London, 1822. This work contains two small maps and
many engravings. (The map of the Eastern Desert is unfortunately
wanting in the Khedivial Library copy, which is the only one I
have seen.)]
[Footnote 4: BELZONI, _Narrative of the Operations and Discoveries
in Egypt and Nubia, and of a Journey to the Coast of the Red Sea,
in search of the ancient Berenice_. London, 1820.]
[Footnote 5: _Plates illustrative of the Researches and Operations
of G. Belzoni in Egypt and Nubia._ London, 1822. (This is a large
folio atlas of 44 plates.)]
[Footnote 6: LINANT DE BELLEFONDS, _L’Etbaye_, Paris (N. D., but
the title of the map accompanying the work gives the date as 1854).]
[Footnote 7: WILKINSON, _Topography of Thebes and General View of
Egypt_. London, 1835. pp. 415-422. _Modern Egypt and Thebes._ London,
1843. Vol. 2, pp. 389-394.]
[Footnote 8: WELLSTED, _Notice of the Ruins of Berenice_. Journal
of the Royal Geographical Society. London, 1836. pp. 96-100.]
[Footnote 9: _Red Sea and Gulf of Aden Pilot._ 5th edition. London,
1900 (with several later supplements). _Admiralty Charts of the Red
Sea._ Sheets 2 and 3.]
[Footnote 10: At Halaib Fort the difference is as much as 1′ 53″,
or nearly 2 miles; _see_ p. 66.]
[Footnote 11: This should not be confounded with the higher Gebel
Faraid to the northward.]
[Footnote 12: Qash Amir is quite a separate mountain from Gebel Elba,
not part of the same range as the chart indicates.]
[Footnote 13: BARTH, _Reise von Assuan über Berenike nach
Kosser_—Zeits. für allgem. Erdkunde. Berlin. Vol. VII (1859),
pp. 1-31. (There is no map to this work, but the route followed
is easily traceable on a modern map owing to the place-names being
given in the journal.)]
[Footnote 14: V. HEUGLIN, _Reise in Nordost Africa und längs des
Rothen Meeres im Jahre 1857_. Petermann’s geogr. Mittheilungen,
1860. pp. 332-335. (This paper is accompanied by a map, which is,
however, lacking in the copy of the Khedivial Library).]
[Footnote 15: This I think is an error. A small isolated granite hill
west of Berenice is called Sikeit, and has been visited by Barth and
myself; but it is devoid of ruins. My Arabs called Berenice _Medinet
el Haras_.]
[Footnote 16: There was no “Geziret Elba” known to the sailors
of Halaib at the time of my survey. The “Elba Island” of the
Admiralty Chart is called Geziret el Dibia; it is a very small island,
which looks like a boat from a distance.]
[Footnote 17: Though the Bisharin are now very orderly and friendly,
the ancient dread of their country still persists to such a degree
that it is almost impossible to persuade Ababda Arabs to go near
the Elba district.]
[Footnote 18: SCHWEINFURTH, _Reise an der Kuste des Rothen Meeres
von Kosser bis Suakin_, Zeits. für allgem. Erdkunde. Berlin, Band
XVIII (1865), pp. 131-150, 283-313, 320-384. A special account of
the Elba district is given with a map, in another paper, _Das Land
am Elba- und Soturba-Gebirge_ in Petermann’s geog. Mittheilungen,
1865. pp. 330-340. Schweinfurth also published several other papers
dealing with the rich botanical results of his expedition.]
[Footnote 19: I found many of the natives could not recognise the name
Halaib, which has become the official name of their village. They
call it “Oleiyib,” sounding the final consonant only slightly;
so that Schweinfurth’s “Elei” is not very different from the
local name.]
[Footnote 20: COLSTON, _Journal d’un voyage du Caire
à Keneh, Bérénice et Berber_. Bull. Soc. Khédiv. de
Géographie. 1886. pp. 489-568.]
[Footnote 21: PURDY, _Reconnaissance entre Bérénice et
Berber_. _Ibid._ pp. 431-435, with a map.]
[Footnote 22: CORA, _La route de Kéneh à Bérénice levée en 1873,
par le Colonel R. E. Colston_. Bull. Soc. Khéd. de Géog. Cairo,
Sept. 1891. pp. 533-538, with map.]
[Footnote 23: GOLÉNISCHEFF, _Une Excursion à Bérénice_. Recueil
de Travaux. Vol. XIII (1891), pp. 75-96.]
[Footnote 24: Golénischeff names this place _Abu Greïa_, a name
which he remarks is the same as that of a station near Berenice. Garia
Abu Medrik is the name given to it by the Arab guides accompanying
the Survey expeditions.]
[Footnote 25: FLOYER, _Etude sur le Nord Etbai_. Cairo, 1893.]
[Footnote 26: _Further Routes in the Eastern Desert of Egypt._
Geog. Journal. London, 1893. pp. 408-431.]
[Footnote 27: _Notes on the Geology of the Northern Etbai._
Quart. Journal Geol. Soc. London, 1892. pp. 576-582.]
[Footnote 28: Professor HULL, in the discussion on Floyer’s paper,
suggested, even in the absence of specimens, that Floyer’s “blue
clay” was really a decomposed Archæan schist. My observations
have proved the sagacity of this suggestion.]
[Footnote 29: BENT, _A visit to the Northern
Sudan_. Geogr. Journal. London. Vol. VIII (1896), pp. 335-353.]
[Footnote 30: MACALISTER, _The Emerald Mines of Northern
Etbai_. Geog. Journal. London. Vol. XVI (1900), pp. 537-549.]
[Footnote 31: _Berichte der Commission für Oceanographische
Forschungen._ Sechste Reihe, Wien 1898, and Siebente Reihe, Wien,
1901.]
[Footnote 32: _See_ p. 65.]
CHAPTER II.
* * * * *
=GENERAL DESCRIPTION OF SOUTH-EASTERN EGYPT.=
* * * * *
In this chapter will be given a brief general account of the district,
under the heads of:—
1. Extent.
2. Relief.
3. Hydrography.
4. Coast-line.
5. Climate.
6. Scenery.
7. Animal and Plant Life.
8. Water Supplies.
9. Geology.
10. Mineral Products.
11. Antiquities.
12. Inhabitants.
13. Languages.
14. Industries.
15. Communications.
16. Government.
The subjects of topography, water supplies, and geology, will be
further considered more fully in succeeding chapters.
=Extent.=
As already mentioned in the introduction, the district treated of
in this volume lies between the parallels of 25° and 22° of north
latitude, and between the meridian of 34° E. and the Red Sea. It
comprises an area of about 56,000 square kilometres (22,000 square
miles).
=Relief.[33]=
The higher mountains of the Eastern Desert generally form the
watershed between the Nile and the Red Sea. This watershed is much
nearer to the coast than to the Nile, with the result that the
eastward drainage is much steeper than to the west.
Commencing from the north (_see_ the orographical map, Plate I),
the principal mountain masses are:—
(i) The Migif — Hafafit — Nugrus — Hangalia — Zabara group
(1,505 metres[34]), cut off to the south by the Wadi Gemal (_Fd_).
(ii) The Abu Hamamid — Hamata — Abu Gurdi group (1,978 metres),
limited on the south by the Wadi Lahami (_Hg_).
(iii) The Um Gunud — Dahanib — Batoga group (1,270 metres), lying
between Wadi Lahami on the north and Wadi Khoda (_Hj_) on the south.
(iv) The Abu Dahr — Orga — Um Tenedba group (1,131 metres),
separating the drainage of Wadi Betan (_Fl_) from Wadis Khoda and
Rahaba (_Hl_).
(v) The Faraid group, the _Mons Pentadactylus_ of Ptolemy, comprising
some very remarkable granite peaks (1,366 metres), lying near the
coast between Wadi Khoda and Wadi Rahaba.
(vi) The Awamtib — Abraq — Dif — Aqab el Negum — Mishbih
group (1,353 metres), forming the tripartite watershed between the
great Wadi systems of Kharit and Alaqi on the west, and that of Wadi
Hodein on the east.
(vii) The Gerf — Abu Hodeid group, a mighty mass rising to 1,736
metres, lying between Wadi Hodein (_Jn_) and Wadi Hasium (_Hs_).
(viii) The Meisah — Adar Qaqa — Is group, between the Wadis
Hasium and Di-ib (_Mr_).
(ix) The Elba — Shendib group (1,912 metres[35]), a great mass of
spiky mountains lying near the sea between Wadi Di-ib and the coast.
Besides these main groups, there are numerous more or less isolated
mountains, of which Gebels Abu Khrug (_Bd_, 870 metres), Hamrat
Mukbud (_Cf_, 890 metres), Zergat Naam (_Ej_, 845 metres), and the
two Niqrubs (_Fn_ and _Fo_, 829 metres and 1,078 metres) are examples.
Some of the mountains, especially the granite “bodkin” of Gebel
Faraid (_Hl_), and some of the peaks of the Elba group, appear to
be unclimbable. A few others are rather dangerous of ascent, as,
for example, Gebel Abu Hamamid (_Ef_) on account of its steepness,
and Gebel Abu Dahr (_Gk_) by reason of combined steepness and rotten
rock, which comes away in tons at a touch. The highest peak of all
within the district, Gebel Hamata (_Gf_), is a comparatively easy
climb from the north.
=Hydrography.=
The course of the main watershed which parts the Red Sea and Nile
drainages is highly irregular both in altitude and direction, as will
be evident from the orographical map (Plate I), on which it is shown
by a red line. From Gebel Hamrat Wogud, in the north, it passes east
of Gebel Atut, thence through the high masses of Gebels Hangalia,
Nugrus, Hafafit, and Migif, beyond which it drops southward through
the low country round Gebel Abu Had. Entering the mountains again
at Gebel Nukheira, it takes an eastward bend, passing along the
great ridges of Gebels Abu Hamamid, Um Usher, Um Hasidok, and Ras el
Kharit. Striking southward across the head of Wadi Kharit, it courses
through the mountains of Mikbi and Abu Gurdi, thence dropping to the
south on the plain near the hills called Marwot Elemikan. Turning here
sharply westward over the plain, it passes through the hill-mass of
Gebel Abu Derega and on to Gebel Zergat Naam, south-west of which it
crosses the low tract at the head of Wadi el Arned to the sandstone
plateaux of Dagalai, whence it courses a little to the west of
Gebel Um Reit and enters the mountainous tract of Gebel Aqab el
Negum. Its further course has not been traced in detail, but from
guides’ statements and the indications of the main drainage-lines
it is believed to run as shown on the map, in a great curve through
the two sharp peaks of Gebel Sheyenit to the west of Gebel Mishbih,
and then in another flatter curve south-eastwards to Gebel Soaorib,
at the head of Wadi Hasium. Continuing along the mountain ridges of
Gebel Soaorib, it crosses to Gebel Is,[36] separating the Wadi Is
from the heads of Wadi Alaqi on the Sudan frontier.
The watershed is for a great part of its course quite impassable for
camels. The principal places where it can be crossed are at the head
of Wadi Nugrus, near Abu Had, the Wadi Marasan between Huluz and
Wadi el Sheikh, the heads of Wadi Lahami, Wadi el Fil, Wadi Arned,
and Wadi Um Reit, passes at Aqab el Negum and Hamrat el Feg, near
Gebel Mishbih, the head of Wadi Hasium, and the pass of Adar Ameit,
north of Gebel Is. All these places are practicable for baggage
camels, though in some of them, as, for instance, at the head of
Wadi Nugrus, care is required because the track is steep and stony.
The principal drainage-basins are shown on the small scale map
on Plate II. The westward drainage ultimately reaches the Nile by
the three main trunk wadis of Shait, Kharit, and Alaqi; Shait and
Kharit enter the Nile Valley at Kom Ombo, while Alaqi debouches near
Dakka. The eastward drainage is much more complex, the principal
trunk wadis, such as Um Khariga, Gemal, Khoda, Rahaba, Hodein, Ibib,
Di-ib, and Serimtai, being separated by very numerous minor wadis
draining independently to the sea.[37]
Nearly all the wadis contain vegetation in the form of trees and
bushes, and plant life flourishes as a rule far more luxuriously in
wadis draining seawards than in those leading to the Nile. Feqoh,
Naam, and the lower reaches of Hodein are, however, exceptionally
barren. Forming, as they do, the only possible roads, furnishing
the entire supply of camel food, and containing most of the wells,
the wadis are to the desert what the Nile is to Egypt proper. The
intervening mountains are of no interest to the Arabs, except when
they contain water-reservoirs. Hence the place-naming starts from
the wadis, even the smallest of which have names unless they are
barren. Mountains are generally named after the nearest wadi, and may
thus have two names when situated between two wadis, the particular
name used depending on which side the mountain is seen from.
=Coast-line.=
The coast-line of this part of Egypt is somewhat irregular, the
peninsula of Ras Benas forming a prominent projection in latitude
24°. In the south part of the area the eastward extension of the
country, culminating in Ras Hadarba (Cape Elba of existing maps),
is very marked, extending nearly to 37° of east longitude. The
coast is almost entirely fringed by coral reefs, passage through
which is only possible at certain points, and then only with the
utmost care in navigation.[38] Between the feet of the mountains and
the sea there extends a gently sloping plain, varying in width from
about eight to twenty-five kilometres, covered with sand, over which
the drainage meanders in shallow courses, often only traceable by
the vegetation which occurs along them. A rather surprising result
brought out by the levelling observations is that the slope of the
coast plain, even where it looks flattest and sandiest, is as steep
as the floors of some of the wadis draining on to it, and several
times more steep than the beds of the wadis which drain westwards
to the Nile, its fall seawards averaging six metres per kilometre
and reaching over ten metres per kilometre in some sections.
=Climate.=
The climate of the district is predominantly hot and dry to the
west of the watershed, hot and moist eastward of it; but very cold
weather is apt to prevail for a few weeks in January and February,
with strong north winds, on both sides of the watershed, and the
transition from piercing cold to great heat at these times is often
brought about very suddenly by a change of wind direction. There
is seldom any frost, but water-bags are occasionally frozen on the
mountain tops at night. Cool north-west winds prevail in the north
part of the area, while hot damp winds from the south-east are usual
in the south. In the central part, round Berenice, absolute calms are
frequent.[39] The highest mountain-masses are frequently swathed in
clouds for weeks together, especially from January to March. The hot,
dry, sand-laden winds called _Khamsin_ occasionally blow for four
or five days together in March and April; at these times the shade
temperature rises to over 45° C., and the air is thick with sand and
dust. Rain falls in most years, but its quantity is very variable;
in some years there is barely enough to keep the wells supplied, and
much of the vegetation withers; in others, heavy storms produce wild
downrushes in the wadis, filling them for short periods with raging
torrents. Curious electrical and optical phenomena can sometimes be
seen on the mountain-tops during storms and in mists.[40] The Elba
region is seldom free from clouds, and receives far more rain than
any other portion of the area, forming in fact the northern limit of
the rainy tropical zone; it is in consequence relatively well wooded,
while the other mountains are a dreary waste of naked rocks.
PLATE II.
[Illustration: SKETCH-MAP OF SOUTH-EASTERN EGYPT.
Showing Drainage-Basins.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)
Scale 1:2,000,000.]
=Scenery.=
The predominant types of scenery are extensive sandy plains and
gaunt rugged mountains. In the low-lands, pleasant relief from
the stony monotony is afforded by the trees and scrub which occur
along most of the wadis, though their struggle for existence is
often evidenced by miles of withered and blackened scrub in places
which a few years ago were green and flourishing. The bareness
of the mountains becomes slightly relieved in the Elba district,
where beautiful trees and flowering plants thrive high up the
mountain-side along all the drainage lines. As to the forms of
the mountains, one sees extensive broken sandstone plateaux at
Gebel Abraq (_El_), remarkable rounded granite bosses at Gebels
Muelih (_Ab_), Nugrus (_Dc_), Selaia (_Fh_), and Um Rasein (_Jr_),
jagged and spiky granite peaks in the mountains of Faraid (_Jk_),
Qash Amir (_Os_), and Elba (_Ps_), and broken masses of gneiss,
dark schists and serpentines at Gebels Hafafit (_Dc_), Hangalia
(_Dc_), Abu Hamamid (_Ef_), Hamata (_Gf_), and Gerf (_Hp_). Perhaps
the most remarkable of all the peaks are those of Faraid (_Jk_),
which from the north look like the expanded fingers of a huge hand,
whence they received their name of _Mons Pentadactylus_ in antiquity,
while one specially sharp peak is styled very appropriately “the
Bodkin” on Admiralty Charts. The mass of Elba forms a very fine
view from the north, but the prevalence of clouds about its summits
frequently hides it from view for months together. The views from the
mountain-tops are extensive and beautiful, especially at sunrise and
sunset, when the peaks take on wonderful colours, and the views from
the summits when the entire lower landscape is bathed in clouds,
through which only the higher peaks project like islands from
a great sea, are not less remarkable. Though a good look out was
kept from the highest mountains across the sea, the mountains of
the opposite shore of Arabia were never with certainty made out;
the cone of Zeberged Island was, however, often seen. It is stated
by d’Anville, on the authority of Castro,[41] that both the Arabian
and African mountains can be seen from the summit of Zeberged.
=Animal and Plant Life.=
Both animal and plant life is mainly confined to the drainage
lines. Of wild animals suitable for human food, gazelles can be
shot fairly frequently in the south part of the area, but are very
scarce in the north. Sand grouse and partridges can occasionally
be obtained round Abu Saafa, while doves are very abundant in the
groves near Bir Akwamtra, at the foot of Gebel Elba. Ibex were never
seen with certainty, though their horns and lairs were often found
on the mountains. Conies inhabit the rocks near Bir Abraq and Bir
Madi. The wild ass has disappeared from the area, as also has the
ostrich, though fragments of ostrich eggs picked up here and there,
and drawings of this bird on the rocks, attest its presence here in
recent times. Vultures, kites, and ravens are everywhere in evidence,
and several kinds of smaller birds, such as swallows and wagtails,
are often seen about the greener wadis. Lizards of many kinds are to
be seen. Scorpions and snakes are seldom met with. Of butterflies
and moths, especially the latter, many varieties occur. The common
fly occurs in such numbers as to be a great pest, but mosquitoes and
sand-flies are practically absent. Camel ticks infest the ground
under all trees used as shade by travelling Arabs. Earwigs are in
some places very abundant, and a great variety of beetles and bugs
occur. Near the sea, whole armies of crabs are to be seen marching
on the shore, and hermit crabs are very numerous in all sorts of
gasteropod dwellings.
Of plant life the district contains a great variety. The north and
central parts of the area contain the same trees and bushes as abound
further north in Egypt,[42] and camel food is moderately abundant. As
Elba is approached, many beautiful flowering plants not found further
north are met with, while in the clefts of the slopes of Elba itself
is a far richer vegetation than occurs wild in any other part of
Egypt. I found the approach to Elba was stopped for baggage camels
some four kilometres from the summit owing to the closeness of the
trees, and the ascent on foot up the clefts of the mountain-face
for the remainder of the way was more like going through an English
wood than up a desert mountain. Many varieties of sweet-smelling
flowers and some fruit-bearing trees unfamiliar in Egypt were seen,
while mosses and lichens covered the tumbled masses of granite in
many places. Schweinfurth, who examined the botany of this region
in 1864, found that of 300 species of plants collected in the Elba
district, the vast majority were of Abyssinian types; scarcely 100
were living in other more northerly parts of the Eastern Desert of
Egypt, while still fewer are indigenous to the Nile Valley, and only
fifteen species were of those found wild in Europe.[43]
=Water Supplies.[44]=
The sources of water comprise _galts_ (rock basins forming rain
water reservoirs in the mountains), springs and wells. Of these,
_galts_ yield the purest water, and form the principal supply of the
pastoral Arabs, except in years of no rainfall, while springs and
wells, the latter usually rude excavations in the alluvia of wadis,
are most used by travellers from their easier accessibility. Small
_galts_ are called _megal_ (Ababda) or _megwel_ (Bisharin); they
are frequently accompanied by small springs.
The small scale map on Plate III, which shows all sources known
to exist within the area, gives a good idea of the distribution of
water supplies. Water is scarce in the western parts of the country,
Bir Abu Hashim being the only source within a radius of about sixty
kilometres of itself, but _galts_ and wells are fairly frequent among
the mountainous tracts further east. The springs of Abraq and Abu
Saafa are the most important sources in the central area. The portion
of the country under the Sudan Administration is far richer in water
that the Egyptian part, containing numerous fine wells and springs,
such as Birs Meneiga, Abu Hodeid, Akwamtra, and Frukit. The coast
plain is waterless, except for salty wells near the sea.
Water can usually be obtained at intervals of about two or three
days when on the march, and in some parts much more frequently. The
water of certain wells and springs has a purgative effect due to
the absorption of magnesium salts, especially after a long interval
without rain. That of others, again, such as Muelih and Shalatein,
is so salty as to be only drinkable by camels.
=Geology.[45]=
The rocks composing this part of Egypt are principally igneous and
metamorphic deposits of very ancient origin. Granite is most prominent
in the Nugrus, Faraid, and Elba areas, schists and diorites cover a
large portion of the remaining country, and huge masses of serpentines
form the mountains of Abu Dahr, Korabkansi, and Gerf. Of sedimentary
rocks, plateaux of Nubian sandstone (Cretaceous) cover large areas
round Bir Abraq and westward of it, while a narrow belt of the
same rock also occurs along the sea coast in the north part of the
district. Gypseous limestones (Miocene?) form the hills of Ras Benas
and occur along the coast north of Wadi Lahami, as well as in small
areas near the coast further south in the neighbourhood of Halaib.
PLATE III.
[Illustration: SKETCH-MAP OF SOUTH-EASTERN EGYPT.
Showing the Water-sources and the Roads connecting them.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)
Scale 1:2,000,000.]
Crushing of the older rocks is almost everywhere strongly evidenced,
but faulting is difficult to trace except in the sandstone areas,
where it is strongly marked. The presence of clearly defined
overthrust faulting in the Abraq area shows that tangential earth
movements, so rare in this part of the world,[46] have not been
altogether absent.
=Mineral Products.=
The mineral resources of this part of Egypt are not of very great
importance, owing partly to its inaccessible situation and desert
character. Gold and copper ores occur in places; other localities
contain beryl and peridots, while others, again, bear iron ores,
gypsum, sulphur, steatite, asbestos, and magnesite, and good building
stones abound over large areas.
The presence of ruins and excavations at places like Hangalia, Sikait,
Zabara, Romit, and Darahib, are evidence of mining activity in the
past, but the mean nature of the accommodation for the workers,
and the presence of old stone hand mills where gold was the thing
sought for, confirm the statement of Diodorus[47] that the mines
were worked by miserable convicts.
In recent years much prospecting has been done to test whether the
ancient mines could be developed and made commercially productive
under modern conditions. In the case of many areas, including that
round Darahib, the mines of which are believed to be those referred
to with a map in the Turin papyrus of the Nineteenth Dynasty,[48] the
prospecting licences have been surrendered to the Government because
the results were unfavourable. In a few other cases prospecting is
still being carried out, and in three localities the results have
been sufficiently encouraging for exploitation to be undertaken.
The following tables, compiled from information supplied by the
Mines Department, give particulars of the prospecting licences and
mining leases at present (1912) held within the area described in
this book:—
PROSPECTING LICENCES.
--------+----------------+---------+----------+-----------------------
Licence|Date of Licence.|Principal|Holder of |Situation of Area
No. | | Mineral | Licence. |licensed.
| | sought. | |
--------+----------------+---------+----------+-----------------------
49 | Nov. 1, 1909 | Gold. |Mr. Mack. |Kurdeman district.
| | | |
50 | „ 1, 1909 | „ | „ |Sabahia district.
| | | |
75 | May 14, 1911 | „ | „ |North-east side of
| | | |Gebel Zabara.
| | | |
59 | Feb. 17, 1910 |Sulphur. | Mr. |Gebel Ranga, near the
| | |Venizelos.|mouth of Wadi Abu
| | | |Ghusun.
| | | |
60 | „ 17, 1910 | „ | „ |Adjoining the
| | | |foregoing.
| | | |
61 |March 19, 1910 | „ | „ | „ „ „
--------+----------------+---------+----------+-----------------------
MINING LEASES.
------+--------------+----------+----------+-----------+-------------
Lease|Date of Lease.| Period | Mineral | Holder of |Area leased.
No. | |for which |exploited.| Lease. |
| | granted. | | |
------+--------------+----------+----------+-----------+-------------
13 | Dec. 1, 1910 |30 years. | Gold. | African |25 acres
| | | |Reefs, Ltd.|near Gebel
| | | | |Um el Tiur
| | | | |el Tahtani.
| | | | |
15 | Jan. 1, 1912 |30 years. | Gold. |Mr. Wells. |25 acres
| | | | |near Gebel
| | | | |Sukari.
| | | | |
55 | June 1, 1906 |30 years. | Peridot. | Peridot & |Zeberged
| | | | Egyptian |(St. John’s
| | | | Gems Co., |Island).
| | | | Ltd. |
------+--------------+----------+----------+-----------+-------------
Of the above three mining leases, the last mentioned (the Peridot
and Egyptian Gems Co., Ltd.) is the only one under which any
considerable exploitation has been carried on, large numbers of
beautiful peridots having been obtained from the mines. The two
gold mining undertakings have been commenced too recently for much
to have been as yet accomplished.
=Antiquities.=
The archæological remains of pre-Arab times in this part of Egypt
comprise the small ruined temples of Berenice and Sikait, the ruins
of stations along the old mining roads, the ancient mines with the
rude habitations of the miners, and sundry markings on rocks near
the roads.
The =Temple of Berenice= is a low inconspicuous structure measuring
only some ten metres square, containing five small rooms and a tiny
corridor and staircase.[49] Owing to its exposed situation on the
coast and the soft limestone (from Ras Benas) of which it is built,
it is in a very dilapidated condition, and it is difficult to make
out many of the inscriptions on its walls. The axial direction of
the temple (63° 20′ east of true north) appears to show that
it was oriented to face the rising sun at the summer solstice. Of
the village (one can hardly call it a city) of Berenice, only
insignificant remains exist near the temple. The houses were mere
hovels built of rough lumps of coral.
There are three =temples in Wadi Sikait=; they are small rock-hewn
structures in even worse preservation than that of Berenice.[50]
Many attempts have been made to trace the =ancient mining roads=
mentioned by classical writers. The stations on the road from _Koptos_
(Quft) to Berenice, enumerated by Pliny and Antoninus, have not been
with certainty identified. The absence of any reliable map of the
main features of the country has hitherto prevented travellers from
locating the positions of stations found, while in careful surveying
it has generally been necessary to travel by other roads than the
ancient ones, so that it cannot be hoped that all the ruined stations,
many of which are invisible till one is close to them, have been
included in the maps. Now that all the principal features of the
country have been accurately laid down, it will be much easier for
future travellers to locate precisely any ruins they may come across.
Of the road leading from _Contra-Apollinopolis_ (Edfu) to the
emerald mines of Sikait and Zabara, much more is known, this route
having been traversed by Golénischeff[51] and most of its stations
located by the Geological Survey. Leading from Edfu, past Bir Abad,
the ruins of a large station and rock temple occur at a distance
of about forty-five kilometres from the Nile, at a place now called
_Kanais_ (the churches), where a well yielding good water was sunk
three years ago by the Mines Department. About forty-five kilometres
further on is the station called Gariat Abu Medrik, where there are
two ancient stucco-lined cylindrical reservoirs, but no well. At the
next station, called Samut, there is a good well in the centre of a
large rubble ruin. As all the stations just mentioned lie outside
the limits of the maps which accompany this memoir, I give their
approximate geographical positions below:—
------------------+-----------+------------+-----------
Station. |Latitude N.|Longitude E.| Altitude
| | |above Sea.
------------------+-----------+------------+-----------
| | | metres.
| | |
Edfu | 24° 58′ | 32° 54′ | 90
| | |
Kanais | 25° 0 ′ | 33° 19′ | 205
| | |
Gariat Abu Medrik| 24° 55′ | 33° 41′ | 295
| | |
Samut | 24° 49′ | 33° 54′ | 340
------------------+-----------+------------+-----------
The next station after Samut appears to have been the ruins near
Gebel Dweig. Further on, after passing over the watershed, is
another station with two cisterns in a semicircular enclosure. The
road continues past Gebel Abu Had to the Wadi Gemal, where there are
two more cisterns, this time in a triangular enclosure, and thence
up to the Wadi Nugrus and Wadi Sikait to the mines. The Edfu-Sikait
road may have joined the Quft-Berenice road at the Wadi Gemal station.
A third ancient road is believed to have led northward from Berenice
to Qoseir, along the coast; while a fourth, from near Dakka on the
Nile up the Wadi Alaqi to the gold mines of the south, is now a
regular route to the Nile Valley Company’s mine of Um Gariart.
The =ancient emerald mines of Zabara and Sikait= consist of numerous
irregular shafts, mostly of no very great depth, excavated in schists
of micaceous and talcose types. The =old gold mines=, such as those
at Sukari, Um Eleiga, Seiga, Romit, and the Darahib district, are on
a considerable scale, excavations having been carried on in quartz
veins to fair depths. The dwellings at the mines were for the most
part only miserable hovels of rubble stone. A view of those of Um
Eleiga is given on Plate IV. The ancient quartz-grinding mills, mostly
made of a hard diorite, are frequently found among the ruins of the
hovels. There is no clear evidence that any of the mines yielded a
very rich output; the workings were of the nature of penal settlements
(Prof. Mahaffy[52] has aptly termed them a “tropical Siberia”)
in times when life and labour were cheap, and a very moderate yield
may under those conditions have been satisfactory.[53]
PLATE IV.
[Illustration: Ruins of Um Eleiga. Gebel Abu Dahr in the Background.]
[Illustration: Ruins in Wadi Shenshef.]
Besides those at the mining camps and stations, there are some
other extensive collections of ruins in the district, two of the
most considerable being at Shenshef and Bir Meneiga. The =ruins at
Shenshef= (_see_ Plate IV) are in part those of well-built houses,
furnished with doors and windows, formed of slabs of fissile quartzose
schist, quarried in the neighbouring hills. There are wells at
Shenshef, but apparently no mines; the presence of watch towers on
the hills, and the peculiar situation of the place, suggest that it
may have been a slave dealer’s stronghold where slaves were herded
till they could be shipped from Berenice. The better houses may have
been those of the overseers, while the ruder hovels accommodated the
slaves, and sentinels at the watch towers prevented any attempt at
escape. The =ruins at Bir Meneiga=, though extensive, are very rude,
and probably only represent a camping ground near the springs. A large
rubble enclosure near Abraq springs has been thought by Purdy[54]
to have been a hunting station of the Ptolemies.
In many places there are =marks and drawings on the rocks= near
roads. These are frequently spirited representations of animals,
among which the ostrich is often seen. At the Galt el Aguz, near
the watershed at the head of one of the branches of Wadi Garara,
the drawings are accompanied by rude Greek inscriptions. At Abu
Saafa, one of the springs issues from a niche cut in the sandstone,
having a carved cornice with the remains of a Greek inscription on it.
Another class of remains are found scattered over the area in the
form of =cylindrical rubble piles=, four metres in diameter and from
one to two metres high. The natives consider these to be tombs of
pre-Arab date.
Of =Arab tombs= in the area, the most considerable is that of
Sheikh Shadli, near Gebel Abu Hamamid, a view of which is shown on
Plate V. It is a well-built tomb of several domes, inhabited by a
Moorish guardian. A yearly pilgrimage is made to this place by the
Ababda Arabs, who hold the memory of Shadli in high veneration. The
next largest tomb is probably that of Sheikh Hamid, near Abraq
springs. Near the nose of Ras Benas is a large sheikh’s tomb,
where sailors perform their devotions, and smaller tombs of the
same type, built of drift-wood, are to be seen at other points near
the coast. Cemeteries of small Arab graves exist near every well
and spring.
=Inhabitants.=
The South-Eastern Desert of Egypt is inhabited by nomad Arabs of the
various Ababda and Bisharin tribes.[55] Ababda (Ashabab and Meleikab)
occupy the country north of Muqsim and Bir Shalatein, while Bisharin
(Hamedorab, Kurbeilab, Koatil, and Balgab) inhabit the country to
the south.[56] Only guesses are available as to their numbers, but
it is not probable that they comprise so much as one inhabitant for
each five square kilometres. A casual journey through the country
would lead one to think that it was inhabited to an even less
degree, but the Arabs mostly camp in selected narrow wadis out of
sight of the traveller. They are a people of good physique, hardy,
intelligent, and fair workers if once their employer knows how to
handle them. They share, however, in the universal Bedouin dislike to
protracted regular work; after a few months of regular routine, even
the semi-nomad routine of a survey-expedition, they experience strong
desires for their own independent roaming life, and it is impossible
to retain them for longer periods. Many of the Ababda who are settled
near the Nile have lost their true desert character, and on desert
expeditions men of this class are far less satisfactory than nomads;
they do not know the country, but fear the desert and are continually
desirous of returning to the valley. The better desert guides,
on the other hand, love the wilderness, and they have a perfectly
marvellous geographic instinct. The skeleton on which they arrange
their knowledge is always the system of drainage. If a map of their
country is laid before them, and a few points named to them, they
will delight in tracing out and naming all the wadis and peaks. But
they have very vague ideas of proportion, and can only read a map
when it is laid on the ground in its true orientation with respect
to the meridian. The Ababda are generally regarded as the best type
of Egyptian desert Arab, while my experience of the Bisharin of the
Elba district is that they are superior, in industry, intelligence,
truthfulness, and orderliness, to the Ababda.[57] It is, however,
necessary either to understand the Bishari tongue, or to have men
who can interpret into Arabic, as the great mass of the Bisharin
understand only their own language, which is quite different from
Arabic.[58] Education is very backward, but there is a _kuttab_
(elementary school) at Halaib, where instruction in Arabic reading
and writing is given to boys. All the Arabs are of course Moslems,
but they are not at all fanatical.
PLATE V.
[Illustration: Tomb of Sheikh Shadli.]
[Illustration: Bir Shadli.]
The manner of life of the Arabs is very simple. Most of the men have
only a single cotton wrap about their middle, though some wear the
ordinary galabia and cotton drawers. Their camps are rude tents of
matting about two metres in diameter, but the men commonly sleep in
the open, sheltering themselves from winds by their camel saddles,
covered only with their cotton wrap, which they spread over their
entire bodies, including their heads. They wear no head covering,
having heavy “mops” of curled black hair plentifully supplied
with mutton fat. Their food consists almost entirely of milk and
meat, of which their flocks and herds give them a plentiful supply;
they eat but little bread, but they are fond of a kind of gruel of
flour and water, and of dates, which are imported from Arabia _via_
Suakin. Only a few of them smoke tobacco, and that generally in
soapstone pipes which they carve out for themselves. Intoxicants are
unknown amongst true desert Arabs. For arms, they carry swords and
knives, seldom fire-arms. Of their tribal customs, I saw but little;
Linant de Bellefonds gives an interesting account of them in his
“L’Etbaye.” On festive occasions, camel-racing and dancing
are favourite amusements.
Slavery appears to be non-existent at present, for in the course of
my twenty months’ wanderings I received no complaint under this
head, as I should almost certainly have done had any oppressive
servitude existed.
=Languages.=
My own study of the Ababda and Bishari tongues has been mainly
confined to their geographical terms. The Ababda nowadays almost
all speak Arabic, and most of their place-names are either Arabic or
closely akin to it. A marked feature of their tongue is a fondness
for diminutives. Thus we have _Sellim_ and _Seleim_, _Hafafit_ and
_Hefeifit_, _Faraid_, and _Fereyid_, _Wadi_ and _Wadai_, in each of
which the second of the pair is a diminutive formed by vowel-change,
generally accompanied by a change in the placing of the stress. The
commonest special geographical terms in Ababda country are: _erf_,
a ridge; _rod_, a tributary wadi; _talet_, a small tributary wadi;
_kab_, a watershed or pass; _hamrat_, a (red) granite mountain;
_zergat_, a black mountain; _galt_, a rock basin containing rain
water; and _megal_, a small water hole. Thus we have such names as
_Hamrat Selma_, _Zergat Naam_, and so on, the name often giving a
clue to the nature of the rock.
As soon as one passes into Bisharin country the change in the
nature of place-names is very striking. The definite article is no
longer _el_, but _o_, _u_, _ei_, _e_ (masc.), and _to_, _tu_, _tei_,
_ti_ (fem.). Many place-names end in _ai_ and _oi_. The principal
geographical terms are: _kwan_, a wadi; _da-aiyob_, a depression from
which there is no drainage outlet; _aweib_ and _riba_, a mountain;
_kulet_, a hill; _megwel_, a water hole; _adar_, red; _hadal_,
black; _sotai_, green; _eire_, white; _sarara_, deep; _salala_,
rather deep (applied to wells). Hence we get such combinations as:
_Hadal Aweib Meisah_, the black mountain near Wadi Meisah; _Eir
Arib_, the white (granite) rock; _Sarobi Kwan_, the wadi where
the Sarob plant (_Capparis sodada_) grows; _Bir Sararat Seyet_,
the deep well in Wadi Seyet, and so on. A mountain called _adar_ is
generally of red granite, while one called _hadal_ is usually diorite
or serpentine. _Asotriba_, the green mountain south of Gebel Elba,
receives its name from the vegetation on it.
=Industries.=
The principal industries carried on by the desert Arabs are the
rearing of camels, sheep and goats, especially the first-named. The
Bisharin devote much attention to camel-breeding, and supply many
animals annually to the Coast Guard Administration. Their camels are
very superior animals, and need to be hardy in order to negotiate
the steep mountain passes of their country. Sheep and goats can be
bought cheaply in the south, and are driven in to Aswân for sale
at the higher rates there prevailing. It is common to find a flock
of hundreds of sheep being watered at wells such as Bir Abu Hashim
and Qoleib on the route to Kom Ombo; but many animals drop and die
on the weary march from well to well.
Charcoal burning has been practised, especially in the Ababda country,
but is not much carried on now; this industry deserves strong
opposition, for it only impoverishes the country, and the _seyal_
trees are few enough for the support of camels in years of drought.
In recent years some employment has been found for the Arabs
by prospectors for mining companies, both as miners and for
camel-transport, and they are occasionally, as in the present
expedition, employed on Government work.
For the information of future travellers, it may be worth
while to mention the prices paid for local labour on the survey
expeditions. The men and animals were all the best obtainable of
their particular class, and the prices include saddles and fodder
for camels, their own provision of water and food for the men, and,
in the case of sheikhs, postmen, and guides, their riding camels
and fodder:—
_Mills, per day._[59]
Responsible sheikhs in charge of all Arabs 200
Skilled guides (also employed as beacon builders) 150
Postmen journeying regularly to and from the
Nile Valley 150
Baggage camels, each to carry 300 pounds’ load,
with one driver to every two camels, the drivers
to act as general labourers at a camp and to
collect wood and water and to carry supplies up
the mountains when required 120
Riding camels 120
Porters 70 to 80
A small amount of agriculture is practised in the Wadi Di-ib, slightly
south of the Sudan frontier, but there is none actually within the
district here described. My camels were fed for some time on _durra_
(Indian corn) brought from Wadi Di-ib.
A little fishing is carried on near Berenice and at Mersa Shab and
Halaib, but only for the food of the fishermen, who subsist almost
entirely on it, and thus recall the _Ichthyophages_ of Ptolemy. When
I had abundance of excellent fish at Shab and Halaib, I noticed
that but few of my Bisharin cared to partake of what was to me a
very welcome change of diet.
Halaib is the only permanent village, and even it is merely a
miserable collection of wooden huts and tents, where trade is
confined to dates, fat, corn, sugar, and such like necessaries;
supplies are brought by boat from Suakin and sold to the local Arabs.
=Communications.=
There are numerous camel-roads connecting the various wells with each
other and with the Nile, the principal of which are indicated on Plate
III (p. 26). The most usual starting points from the valley are Edfu,
Kom Ombo, Aswân, Dakka, and Berber. The roads lie mostly along wadis,
and are far from being very direct, being necessarily so chosen as
to pass water supplies and to avoid very steep places. From Aswân
or Kom Ombo, Berenice can be reached in about seven or eight days
by luggage camels, and the roads are fairly good; water is least
scarce on the Kom Ombo road, which takes advantage of the wells of
Qoleib and Abu Hashim. Between any two wells, there are generally
several possible roads. The one taken by any particular traveller is
naturally that which his guides happen to know best, or that along
which the most camel food is to be found at the time; hardly any two
Europeans have journeyed by precisely the same road. A “road”
in desert parlance is only a track by which camels have passed at
some time or other; there is nothing of the nature of a _made_ road,
even along the ancient routes mentioned in the Antonine Itinerary; and
the tracks are sometimes obliterated by sand. Since the opening up of
Port Sudan, the Elba district is most easily reached from that place,
whence it is about 340 kilometres distant, by two roads of nearly
equal length, one skirting the coast and the other more inland; the
latter passes good wells at about two days’ intervals.[60] To reach
Elba from the valley, a camel journey of more than 500 kilometres is
necessary whether Aswân, Dakka, or Berber be the starting point. The
ports of Berenice, Shab, and Halaib are only touched occasionally
and irregularly by coasting boats and Coast Guard steamers. News is
passed orally among the wandering Arabs with remarkable rapidity,
but naturally it frequently gets somewhat modified in transit.
=Government.=
The geographical frontier between Egypt and the Sudan is the 22nd
parallel of north latitude. But for administrative purposes it
has been found convenient to consider all Bisharin Arabs as under
the Sudan Government, and all Ababda under that of Egypt. The
administrative frontier therefore runs between the districts of the
two main tribal divisions, along a zigzag line from Gebel Muqsim,
_via_ Gebel Um el Tiur el Foqani, Gebel Niqrub el Foqani, and Bir
Meneiga, to Bir Shalatein on the coast.[61] A territory of some
16,000 square kilometres in the extreme south-east corner of Egypt
is thus placed for purposes of government under the Sudan mudiria
of Berber, under which arrangement a moawin and small police force
are maintained in the fort of Halaib. The remainder of the area is
administered by the Egyptian mudir of Aswân. In Egypt, the Arabs
are not taxed except in respect of any lands they may own in the
Nile Valley. In the Sudan a tax is levied on each tribe in return
for police protection and other advantages; the tax is paid very
willingly, for the Bisharin are less poor than the Ababda, and
thoroughly appreciate the advantage of good government, while they
have unbounded faith in the justice of Anglo-Egyptian officials in
settling their disputes. One of the incidents which most strongly
impressed itself on my remembrance during my travels in the district
was the meeting near Gebel Korabkansi of an English inspector from
Berber, to whom a number of Bisharin Arabs engaged in disputes stated
their rival claims quietly and reasonably, both sides having the
utmost confidence that the judgment given would be just and fair. In
Egypt, the Arabs are less friendly in their feelings towards the
government, and prefer to settle their differences among themselves;
a circumstance no doubt due to the fact that Egyptian governors
have had their hands full with matters connected with the valley,
and have had no time to become acquainted with Bedouin ideas and
customs, while the Arabs, independent for centuries and very poor,
are afraid of misunderstanding and taxation. It would, I think, be
unfair to tax the true desert Arabs of Egypt, even to the moderate
extent which is done for the Arabs of the Sudan, for their country
is much more barren than that of the Bisharin, and their sources of
income are consequently fewer. In a year of little or no rainfall,
there is not enough vegetation to feed their animals, so that many
are lost, and the only way a tax could be raised at such times would
be by cutting down trees for charcoal; but, as already mentioned,
any encouragement of the charcoal industry would soon impoverish the
country still further, the thorny acacia trees being the principal
reserve camel food in rainless years. That so many Ababda are
settled in and near the Nile Valley is possibly in part due to their
having been driven from the desert by the growing scarcity of trees
consequent on the prosecution of the charcoal industry in the past.
* * * * *
[Footnote 33: The mountains and hills will be found described in
fuller detail in Chapter VI.]
[Footnote 34: The altitudes refer to the highest points of the
groups.]
[Footnote 35: This is the altitude of Shendib, the highest of the
group in Egypt; but the peaks of Asotriba, which is part of the same
mass lying within the Sudan, rise considerably higher.]
[Footnote 36: In the map on Plate I, I have shown the watershed
crossing directly from Gebel Soaorib across the high intervening
mountains to Gebel Is, which is how it appeared to me from my station
on Hadal Aweib Meisah. But Mr. Morrow Campbell’s map (referred to
on p. 15) shows the heads of Wadi Soaorib to extend further west
than I could see them; and if this is correct, as it probably is
since Mr. Morrow Campbell doubtless approached the watershed more
closely than I did, the watershed between Gebel Soaorib and Gebel
Is lies further west than I have shown it on Plate I. In drawing
the wadis on the geological and tribal maps on Plates XX and XXVI,
I have shown the westward extension of the heads of Wadi Soaorib
according to Mr. Morrow Campbell.]
[Footnote 37: The wadis will be found described at length in Chapters
IV and V.]
[Footnote 38: See the _Red Sea and Gulf of Aden Pilot_, published
by the Admiralty.]
[Footnote 39: See my short paper on the meteorology of the Berenice
district in _Survey Notes_, Sept. 1907, p. 325.]
[Footnote 40: I have given short accounts of some of these phenomena
in _Survey Notes_, April 1907, p. 219, and in the _Cairo Scientific
Journal_, May 1908, p. 206.]
[Footnote 41: D’ANVILLE, _Mémoires sur l’Egypte_. p. 234.]
[Footnote 42: _See_ BARRON and HUME, _Topography and Geology of the
Eastern Desert, Central Portion_. Cairo, 1902. pp. 98-104.]
[Footnote 43: SCHWEINFURTH, in _Petermann’s Mittheilungen_, 1865.]
[Footnote 44: For a fuller description of the water-sources of the
region, _see_ Chapter VII.]
[Footnote 45: For a fuller account of the geology, _see_ Chapters
VIII to XI, and the geological map on Plate XX.]
[Footnote 46: SUESS, _The Face of the Earth_. Miss Sollas’
translation. Vol. I. Oxford, 1904. p. 376.]
[Footnote 47: Lib. III, 12-14.]
[Footnote 48: _See_ DUNN, _Notes on the Mineral Deposits of the
Anglo-Egyptian Sudan_, published by the Sudan Government. Khartoum,
1911. p. 15.]
[Footnote 49: For a plan of the temple and notes on its inscriptions,
_see_ GOLÉNISCHEFF, Une Excursion à Bérénice, _Recueil de
Travaux_. XIII (1891). pp. 75-96.]
[Footnote 50: MACALISTER, _Geog. Journal_. Vol. XVI (1900). p. 546.]
[Footnote 51: _Op. cit._ Golénischeff gives sketch plans of the
stations.]
[Footnote 52: _The Empire of the Ptolemies._ London, 1895. p. 130.]
[Footnote 53: DIODORUS (I. 49) probably greatly exaggerated the
value of the produce of the mines. _See_ UHLEMANN, _Handbuch der
gesammten aegyptischen Alterthumskunde_, Zweiter Theil, Leipzig,
1857, pp. 148-151, where a very clear account, mainly derived from
Diodorus, is given of the mining methods used by the ancients.]
[Footnote 54: _Bulletin Soc. Khéd. de Géogr._ 1886. p. 443.]
[Footnote 55: According to Mr. Bramly (The Anglo-Egyptian
Sudan. 1905. p. 91) the Bisharin are not true Arabs, and are of
Hamitic descent.]
[Footnote 56: Regarding the geographical boundaries of the different
tribes, _see_ Chapter XII.]
[Footnote 57: Schweinfurth did not have the same experience in 1864;
but one speaks as one finds. Schweinfurth was reluctant to pass
judgment, not knowing the language, and possibly in the interval
since 1864 the people have improved.]
[Footnote 58: On the Bishari language, _see_ ALMKVIST, _Die
Bishari-sprache_, Upsala, 1881-1885; REINISCH, _Die Bedauye-sprache
in Nordost-Africa_, Wien, 1893; and REINISCH, _Wörterbuch der
Bedauye-sprache_, Wien, 1895.]
[Footnote 59: The millieme is practically equivalent to an English
farthing.]
[Footnote 60: For a detailed description of this road, _see_
Chapter XIII.]
[Footnote 61: Arrêté of the Ministry of Interior, Egypt, June
25, 1902.]
CHAPTER III.
* * * * *
=SURVEYING METHODS AND PRINCIPAL GEOGRAPHICAL RESULTS.=
* * * * *
=Triangulation.=
=Base-Lines=—The triangulation was commenced by measuring a base
line[62] near Gebel Muelih by means of a 100-metre steel tape, which
had been previously standardised at the Khedivial Observatory. A level
tract having been selected, in such a position as to afford easy
connection with points already triangulated from the Nile Valley,
a line about two and a half kilometres long was ranged out, along
which wooden pegs were driven flush with the ground at 100-metre
intervals. The inequalities of the ground between the pegs were
levelled off by tiny embankments and cuttings, so as to enable
the tape to lie flat. On each peg was nailed a zinc plate having a
millimetre scale running in the direction of the line. In measuring,
the tape was laid on the ground, stretched to a constant tension by a
spring balance at each end, in such manner that its end marks fell on
the zinc scales, and readings were simultaneously taken on the scales
at the two ends. Temperatures were taken in several places along
the tape by mercurial thermometers. The operation of measurement
was carried out in the early morning, so as to avoid any large
difference of temperature between the ground and the air. The levels
of the pegs were found by spirit levelling. After correction for the
initial error of the tape, temperature, stretch, and inclination,
the true length of the base-line reduced to sea-level was found,
as the mean of two separate measurements at different tensions,
to be 2,482·280 metres. The azimuth of the line was found by
observations of _Polaris_ at elongation to be 30° 30′ 6″ E. of
N. The geographical position of the west end of the line was found by
triangulation-connexion with the Nile Valley by Mr. Villiers Stuart
to be latitude 24° 53′ 36″·7 N., longitude 34° 4′ 17″·9 E.
A second connexion to a base-line was made near Gebel Um Harba, where
a base had been previously measured by Mr. Villiers Stuart in the
course of his triangulation of the western part of the desert. In
this case the connexion was not made to the actual base-line, but
to another main line tied directly on to it. The data at this point
of connexion from the two triangulations afforded a useful check on
the accuracy of the work, and were as follows:—
------------------+------------------+----------------+------------
|From Mr. Stuart’s | From my |Difference.
| triangulation. | triangulation. |
+------------------+----------------+------------
Latitude N. | 23° 36′ 55″·0 | 23° 36′ 55″·6 | 0″·6
| | |
Longitude E. | 34° 30′ 38″·1 | 34° 30′ 37″·6 | 0″·5
| | |
Length of line | | |
to Dagalai beacon| 13,170·2 metres. |13,167·9 metres.|2·3 metres.
------------------+------------------+----------------+------------
=Reconnaissance for triangulation points= was carried out
simultaneously with the triangulation itself. The distance of likely
looking peaks was determined either by intersecting them from distant
stations, or by special small triangulations from short bases, and
such selection made as seemed most likely to secure well shaped
figures and a good command of surrounding country. As a rule,
the highest summits were selected as main (occupied) stations,
while all other prominent peaks and other features were fixed by
intersection from two or more main stations. The form adopted for
the main triangulation net was a series of quadrilateral figures
with diagonals, combined with centric polygons, all the angles of
the figures being generally measured. The average length of side
was about thirty-five kilometres.
=Beacons.=—Main stations were marked by wrought-iron beacons,
consisting of two lengths of stove piping about 15 centimetres
diameter by 1½ metres long, the upper length fitting into a faucet
made by splaying out the lower tube. Near the top of the tube were
affixed four sheet iron wings, bolted on to angle iron cleats. A
conical cairn of stones was built up round the tube, nearly up to the
wings, so that the beacon when erected was about three metres high,
two metres in diameter across the base of the cairn, and about a
metre wide across the wings. The beacons were taken down while a
station was being occupied, and replaced on leaving.
Intersected points were sometimes marked with a beacon or cairn,
but in general the peaks were simply bisected from several stations,
as it was found that this gave sufficiently accurate results.
=Measurement of Horizontal Angles.=—Angles were measured with a
6-inch theodolite furnished with reading microscopes graduated to
10″ and permitting of reliable estimations to 1″. The angles
between main points were read on four arcs to eliminate circle
errors. Intersected points were observed on one arc only. The average
error of closure of main triangles was 3″·3.
=Field Computation and Plotting of Triangulated Points.=—The
triangles were computed by the ordinary method, but the angles
were rounded off to 10″ to enable the sines to be taken direct
from the logarithmic tables, and the logarithms were only taken
to five places. The length of the sides having been thus found, the
geographical positions were found by the ordinary _L M Z_ computation,
using, however, only two latitude terms and 5-place logarithms,
while azimuths were only taken out to the nearest 10″. The
abbreviated form of computation used will be best illustrated by
an example:—[63]
_Computation of Position of_ △ _No. 260 from No. 275._
_l_ = 20042 m. { φ = 23° 55′ 30″·6
275 {
_Z_ = 64° 29′ 20″ E of N. { λ = 34° 54′ 36″·9
Log _l_ = 4·30194 Log _l_² = 8·604
- -
Log cos _Z_ = 1·63416 Log sin² _Z_ = 1·911
- -
_B_ 2·51194 _C_ = 9·053
------- -----
-
2·44804 = 1·568
------- -----
_d_φ, 1st term = + 280″·6 Log _l_ = 4·30194
-
2nd term = − 0″·4 Log sin _Z_ = 1·95545
-------------- -
_d_φ = 280″·2 _A′_ = 2·50948
-------
= 4′ 40″·2 = 2·76687
-
φ = 23° 55′ 30″·6 Log cos φ′ = 1·96072
-------------- -------
φ′ = 24° 0′ 10″·8 = 2·80615
-------------- -------
_d_λ = 640″·0
Whence = 10′ 40″·0
{ φ′ = 24° 0′ 10″·8 λ = 34° 54′ 36″·9
260 { --------------
{ λ′ = 35° 5′ 16″·9 λ′ = 35° 5′ 16″·9
--------------
In the above, it will be noticed that the azimuth is always noted
as so much east or west of north or south. If this convention be
adopted, one may consider the first term of _d_φ as always +,
and the second term will be + if the azimuth contains the word
south,—if it is from the north, while the total _d_φ is to be added
or subtracted according as one is going north or south. A somewhat
similar convention is adopted in neglecting the sign of _d_λ till
the actual addition or subtraction is made. It was found in the
field that this method prevented any mistake of sign, while being
much simpler to work than one involving angles greater than 90°.
The geographical coordinates thus found were plotted directly on to
the plane-table sheets, on which the graticule at 10′ intervals
was the first thing drawn. The odd minutes and seconds were first
converted into minutes and decimals, and then into kilometres by
multiplying by the factors appropriate to the latitude, so that the
plotting could be done by the ordinary scale of kilometres. To avoid
difficulties of paper-shrinkage, as many points as possible were
plotted at the time of drawing the graticule, and in general the
points had to be plotted as far ahead as possible for controlling
the traversing and sketching.
=Astronomical Observations.=—Astronomical checks on the
triangulation were obtained by observations of latitude at certain
selected main stations 60-120 kilometres apart, and by azimuth
observations for certain main lines.
The method used for =latitude= was that of observing the times of
equal altitudes of three or more stars, selected as near to the
meridian[64] as possible. This method presents great advantages
over the usual _Polaris_ and circummeridian altitudes, in that the
observations are more easily made, and yield much more accurate
results, because uncertainties in refraction are largely eliminated
and the errors of circle graduation are not involved, the altitudes
not being read at all.[65] The theodolite used was the same as
was employed in triangulation, and the times were taken by a half
chronometer watch, preferably one marking sidereal time with a rate
which could be considered negligible during the hour or so occupied
by the observation. The first star taken was usually _Polaris_, and
the vertical circle was left clamped at its altitude. For the other
stars, any dislevelment was corrected by touching up the levelling
screws just before the instant of observation; this was found better,
than taking bubble readings and correcting for slight difference
of altitude.
The method which I found best in the field for reducing
the observations differs somewhat from that described by
Chauvenet. Assuming approximate values for the latitude and watch
error, I first calculated the altitude of each star from the formula
sin _h_ = sin φ sin ε + cos φ cos δ cos _t_
If the assumed latitude and watch error were correct, all the stars
would give the same value for _h_. If not, each star would give an
equation of the form
_h_ + cos _A_ _d_φ + cos φ sin _A_ _dT_ − _h_0 = 0
where _A_ is the star’s azimuth, _d_φ the required correction
to the assumed latitude, _dT_ the required correction to the
assumed watch times, and _h_0 the true altitude common to the three
stars. The values of cos _A_ and cos φ sin _A_ were calculated from
the ordinary formula
sin _A_ = (cos δ sin _t_)/cos _h_
by four-place logarithms (using the approximate values for φ, _t_,
and _h_, since these are quite sufficiently accurate for the purpose)
and inserted into the three star-equations.[66] By then solving the
three simultaneous equations for _d_φ, the required correction to
the assumed latitude was at once obtained.
As the method is one not usually treated of in books on practical
astronomy, I give on the following pages the reduction of an
observation worked out in full.
_Latitude by Equal Altitudes of Three Stars._
Station on Gebel Um Heshenib. January 30, 1906.
Approximate φ = 24° 20′ 50″ N.
„ λ = 34° 51′ 0″ E.
Sidereal watch U. and C. 30811, approximately 2m 22s fast on L.S.T.,
rate negligible.
Observed times of equal altitudes by watch:—
_Polaris_ 3h 33m 54s·2
α _Columbæ_ 3 42 40 ·8
ε _Canis majoris_ 4 24 35 ·8
_Polaris._
Watch time 3h 33m 54s·2
Watch fast 2 22 ·0
------------
L.S.T. 3 31 32 ·2
Star’s R.A. 1 25 9 ·1
------------
_t_ 2 6 23 ·1 = 31° 35′ 46″·5 W. of meridian.
------------
-
φ = 24° 20′ 50″ log sin 1·6151769
-
δ = 88° 48′ 33″·1 log sin 1·9999062
---------
- -
1·6150831 log cos δ 2·3177
-
Nat. (1) 0·4121764 log sin _t_ 1·7193
--------- ------
-
2·0370
- -
φ = 24° 20′ 50″ log cos 1·9595488 log cos _h_ 1·9560
------
- -
δ = 88° 48′ 33″·1 log cos 2·3176870 log sin _A_ 2·0810
- -
_t_ = 31° 35′ 46″·5 log cos 1·9303179 log cos φ 1·9595
--------- ------
-
2·0405
- -
2·2075537 Nat. = 0·011
---------
Nat. (2) 0·0161270
Nat. (1) 0·4121764 log cos _A_ 1·9999
---------
0·4283034 Nat. = 1·000
-
log sin _h_ 1·6317515
_h_ = 25° 21′ 35″·8
Whence the equation for _Polaris_ is
35·8 + 1·000 _d_φ − 0·011 _dT_ − _h_0 = 0 (1)
α _Columbæ._
Watch time 3h 42m 40s·8
Watch fast 2 22 ·0
------------
L.S.T. 3 40 18 ·8
Star’s R.A. 5 36 15 ·6
------------
_t_ 1 55 56 ·8 = 28° 59′ 12″·0 E. of meridian.
------------
-
φ = 24° 20′ 50″ log sin 1·6151769
-
δ = 34° 7′ 45″·7 log sin 1·7490118
---------
-
1·3641887
-
Nat. (1) 0·2313070 log cos δ 1·9179
--------- -
log sin _t_ 1·6854
------
- -
φ = 24° 20′ 50″ log cos 1·9595488 1·6033
- -
δ = 34° 7′ 45″·7 log cos 1·9179112 log cos _h_ 1·9560
------
- -
_t_ = 28° 59′ 12″·0 log cos 1·9418753 log sin _A_ 1·6473
---------
- -
1·8193353 log cos φ 1·9595
--------- ------
Nat. (2) 0·6596830 1·6068
Nat. (1) 0·2313070 Nat. = 0·404
---------
0·4283760
- -
log sin _h_ 1·6318196 log cos _A_ 1·9523
Nat. = 0·896
_h_ = 25° 21′ 51″·1
Whence the equation for α _Columbæ_ is
51·1 − 0·896 _d_φ + 0·404 _dT_ − _h_0 = 0 (2)
ε _Canis majoris._
Watch time 4h 24m 35s·8
Watch fast 2 22 ·0
------------
4 22 13 ·8
Star’s R.A. 6 54 57 ·1
------------
_t_ 2 32 43 ·3 = 38° 10′ 49″·5 E. of meridian.
------------
-
φ = 24° 20′ 50″ log sin 1·6151769
-
δ = 28° 50′ 52″·7 log sin 1·6834857
---------
-
1·2986626
Nat. (1) 0·1989128
---------
-
φ = 24° 20′ 50″ log cos 1·9595488
- -
δ = 28° 50′ 52″·7 log cos 1·9424561 log cos δ 1·9424
- -
_t_ = 38° 10′ 49″·5 log cos 1·8954602 log sin _t_ 1·7911
--------- ------
- -
1·7974651 1·7335
--------- -
Nat. (2) 0·6272853 log cos _h_ 1·9560
------
-
Nat. (1) 0·1989128 log sin _A_ 1·7775
--------- -
0·4283725 log cos φ 1·9595
- ------
log sin _h_ 1·6318215 1·7370
Nat. = 0·546
_h_ = 25° 21′ 51″·5
-
log cos _A_ 1·9034
Nat. = 0·801
Whence the equation for ε _Canis majoris_ is
51·5 − 0·801 _d_φ + 0·546 _dT_ − _h_0 = 0 (3)
Collecting the equations of the three stars, we have
35·8 + 1·000 _d_φ − 0·011 _dT_ − _h_0 = 0 (1)
51·1 − 0·896 _d_φ + 0·404 _dT_ − _h_0 = 0 (2)
51·5 − 0·801 _d_φ + 0·546 _dT_ − _h_0 = 0 (3)
By solving these equations for _d_φ, we find
_d_φ = + 6″·5
whence the latitude is found to be
24° 20′ 56″·5
It may be remarked that the above process was considerably shortened
when it was possible to get a pair of observations on the same south
star both east and west of the meridian, instead of on two separate
south stars. In that case the watch error was found at once from the
difference between the star’s R.A. and the mean of the two observed
times, and the latitude could be found from two equations instead of
three. The condition for this modification of the method was that
a nautical almanac star could be found culminating at an altitude
slightly greater than that of _Polaris_ at a time convenient for the
observation. It is not advisable to select a star which would give too
long an interval between the equal east and west altitudes. The best
results are obtainable when the interval between the two observations
of the south star is about an hour, and when _Polaris_ is near its
transit. Under such circumstances the watch correction is obtained
quite nearly enough for a good latitude; for, as Gauss[67] pointed
out, “the essential condition is not so much that the precise
instant when the star reaches a supposed place should be noted,
as that at the time which is noted the star should not be sensibly
distant from that place.”
The following table shows the latitudes found by observation and
triangulation at the various points. It may be remarked that the
method used for latitude determination was liable to observational
errors of 2″ or so, as well as to errors of possibly more
than double that amount due to plumb-line deflection among the
mountains,[68] so that the observed latitudes were only taken as
checks to prevent any gross error in triangulation being overlooked,
and not for any determination of the figure of the earth, for which
latter purpose more elaborate observations would have been necessary.
--------------------+--------------+--------------+-------------------
|Lat. observed.|Lat. computed | Difference
Point. | | from |computed-observed.
| |Triangulation.|
--------------------+--------------+--------------+-------------------
West Peg, Muelih |24° 53′ 40″·3 |24° 53′ 36″·7 | − 3″·6
Base | | |
| | |
Beacon on Gebel Um |24° 20′ 56″·5 |24° 20′ 49″·2 | − 7″·3
Heshenib | | |
| | |
„ „ Hill near|23° 55′ 33″·2 |23° 55′ 30″·6 | − 2″·6
Gebel Selaia | | |
| | |
„ „ Berenice |23° 54′ 39″·5 |23° 54′ 40″·3 | − 0″·8
Temple | | |
| | |
„ „ Gimeida |22° 46′ 33″·2 |22° 46′ 29″·4 | − 3″·8
Hill | | |
--------------------+--------------+--------------+-------------------
=Azimuths= were determined in the usual manner[69] by elongations
of close circumpolar stars, _Polaris_ or _51 Cephei_ being usually
selected. The azimuth mark used was an ordinary Egyptian _shamadan_
(candlestick with spring feed) with a glass globe, placed at a
distance of one to two kilometres, with its foot firmly bedded in
sand and stones to prevent any motion. The azimuths observed at the
different stations are shown in the following table:—
------------------------+----------------------+---------------------
Station of Observation.| Point to which | Azimuth observed.
| Azimuth is given. |
------------------------+----------------------+---------------------
Peg at West end of |Peg east end of base |33° 30′ 6″ E. of N.
Muelih Base | |
| |
Beacon on Gebel Um |Beacon on Gebel Hamata|45° 15′ 34″ E. of S.
Heshenib | |
| |
„ „ Hill near | „ „ Abu Gurdi |25° 30′ 35″ N. of E.
Gebel Selaia | |
| |
„ „ Berenice | „ „ Kalalat |61° 10′ 31″ W. of S.
Temple | |
| |
„ „ Gimeida Hill | „ „ Hamra Dom | 6° 14′ 46″ E. of S.
| |
| |
Centre of Halaib Fort | „ „ Elba |83° 25′ 0″ W. of S.
------------------------+----------------------+---------------------
The observed azimuths, unlike the observed latitudes, were more
accurate than the results of triangulation, repetition having shown
them to be reliable within 2″ or 3″, an error of which magnitude
would soon be surpassed in the process of continuing a chain of
azimuths with the unadjusted values of the angles of the triangles,
which were the only values possible to be used in the field. On
arriving at an azimuth station, therefore, a fresh chain of azimuths
was begun from the results of the observation, and continued to the
next station where astronomical observations were undertaken. The
accumulated azimuth error was, however, never found to exceed 10″
in any chain, a quantity which could not sensibly affect the computed
positions of points for plotting on the maps.
=Connexion with the Sudan Surveys.=—At the south end of the
area, connexion was made to a number of points triangulated by
the Sudan Surveys, but as the Sudan triangulation was commenced
as an independent piece of work from an observed latitude and a
telegraphically determined longitude, the connexion affords no
check on the accuracy of the triangulations. The difference found
between my positions and those of the Sudan Surveys was practically
constant for all the Sudan points connected, and amounted to 3″·5
in latitude and 26″ in longitude[70]; these figures represent the
errors in the assumed latitude and longitude of the starting point
of the Sudan Surveys, and will be employed as corrections to the
Sudan positions now that a complete chain of triangulation connects
Berber with the Mediterranean.
=Levels of Triangulation Points.=—The altitudes above sea-level
of all triangulation points were determined by vertical angular
measurements carried out at the occupied stations, an actual sea-level
datum being obtained by including rocks awash in the sea among the
triangulated points. To secure constancy of atmospheric refraction
as far as possible, vertical angles were always read in the middle of
the day, where the change of refraction is slowest. For the occupied
stations, refraction and curvature were eliminated by reciprocal
observations. For intersected points the formula _h_ = _d_ _tan_
θ + (1 − _k_)/2_r_ _d_² was used, the value of _d_ tan θ being
first found by five-figure logarithms and then that of the curvature
and refraction correction (1 − _k_)/2_r_ _d_² by means of the very
convenient “Universal” slide rule of Nessler.[71] The value of _k_
found from a discussion of the first few reciprocal observations was
found to be very nearly 0·13, corresponding with the mean of European
determinations, and this value for the coefficient was employed
throughout the work for intersected points.[72] For obtaining the
correction (1 − _k_)/2_r_ _d_² by the slide rule, a mark _R_ was
scratched at 1210[73] on the lower scale of the slide; by bringing
this mark _R_ opposite to the distance (in kilometres) on the lower
scale (or, where the logarithm of the distance was more convenient,
by bringing the mark vertically under that logarithm on the log scale
of the rule by means of the cursor) the correction could be read off
directly on the lowest fixed scale opposite the end-graduation of
the slide. Usually four or five values for the altitude of a single
point were obtained from a corresponding number of stations, and
the mean taken; the various values generally agreed within two metres.
The constant combination of vertical angular measurements with
horizontal ones was of great service from another point of view
from that of providing altitude data for the maps. It frequently
happened that a peak observed at one station could not be identified
among a number of similar peaks visible at another station. When
this trouble arose, the vertical angles offered a way out of
the difficulty. Vertical and horizontal angles were read off to
a number of likely-looking peaks; on working out the triangles to
the nearest minute of the observed angles, the distance of each peak
was obtained on the assumption that it was the one required. Then to
find which of the several peaks was the correct one, the elevations
were worked out, assuming the distances correct; in only one case
would the level agree from the two stations, and this obviously
discriminated the peak required. The working out of the triangles
for this purpose could be done with sufficient accuracy in a very
few minutes by means of the slide rule, and many points were thus
saved from rejection consequent on misidentification.
Checks on absolute level were frequently obtained by observing
depression angles to the sea horizon, using the formula θ = 107·8
√{_h_}, where θ is in seconds of arc and _h_ is the altitude in
metres. But for high stations the horizon is so distant that very
small variations in refraction cause rather large errors in the
result, so that this method only furnished a rough check.
=Summary of Triangulated Positions.=
The following tables give the geographical positions and altitudes
above sea-level of all points triangulated, arranged in order of
diminishing latitude, _i.e._, from north to south. The list includes
the points fixed within the Sudan for connexion with the Sudan
Surveys. Stations occupied are indicated by an asterisk against the
number of the point. It will be noticed that in some cases several
different mountains bear the same name though widely distant from
each other; also that where a single mountain mass possesses several
peaks or summits, each of these has been fixed separately.
SUMMARY OF TRIANGULATED POSITIONS.
--------+--------------------+-----------+--------+---------+---------
Field | | | | |
Number| Name. | Mark. |Latitude|Longitude|Altitude
of | | | N. | E. | Metres.
Point.| | | | |
--------+--------------------+-----------+--------+---------+---------
| | | ° ′ ″| ° ′ ″ |
| | | | |
21 |G. Hamrat Wogud | cairn. |25 9 34|34 20 0 | 1,103
| | | | |
29 |G. Iteima | „ |25 8 1|34 11 13 | 849
| | | | |
* 204 |G. Igli | „ |25 4 6|34 36 16 | 975
| | | | |
* 26a|G. Atut | „ |25 0 56|34 23 49 | 908
| | | | |
* 203 |Erf el Fahid | „ |25 0 5|34 11 52 | 579
| | | | |
14 |G. Hagar Dungash | „ |24 59 12|34 2 33 | 815
| | | | |
* 218 |G. Sukari | „ |24 56 50|34 42 50 | 476
| | | | |
216 |G. Um Tundeba | summit. |24 55 48|34 47 29 | 550
| | | | |
* 202 |Muelih base | E. peg. |24 54 44|34 5 7 | 406
| | | | |
219 |Isolated hill near | summit. |24 54 23|34 54 21 | 190
|sea | | | |
| | | | |
* 201 |Muelih base | W. peg. |24 53 37|34 4 18 | 398
| | | | |
19 |G. Muelih | cairn. |24 52 44|34 0 37 | 707
| | | | |
* 225 |Kurdeman mines | „ |24 52 35|34 41 35 | 525
| | | | |
71 |Marwot Rod el Ligah | „ |21 51 31|34 8 21 | 514
| | | | |
206 |G. Mudergeg | summit. |24 51 0|34 22 1 | 885
| | | | |
205 |G. Hangalia | „ |24 50 29|34 38 43 | 1,241
| | | | |
* 215 |G. Ghadir | cairn. |24 50 9|34 47 22 | 636
| | | | |
* 32a|G. Nugrus | „ |24 48 34|34 35 47 | 1,505
| | | | |
* 25 |G. Migif | „ |24 47 23|34 27 30 | 1,199
| | | | |
* 214 |G. Allawi | „ |24 46 42|34 49 39 | 515
| | | | |
211 |G. Zabara | „ |24 45 21|34 41 53 | 1,361
| | | | |
224 |G. Lewewi | „ |24 44 38|34 46 39 | 654
| | | | |
212 |Ridge near G. Zabara| N. end. |24 43 48|34 40 56 | 1,104
| | | | |
221 |Hill near sea | summit. |24 42 31| 35 3 15 | —
| | | | |
208 |G. Hamrat Selma | „ |24 41 58|34 20 58 | 761
| | | | |
210 |Peak in G. Hafafit | cairn. |24 40 44|34 37 8 | 722
| | | | |
240 |Wadi Gemal island | N. end. |24 40 45|35 9 6 | 0
| | | | |
* 223 |G. Sikait | cairn. |24 39 55|34 48 5 | 771
| | | | |
213 |G. Um Moghar | summit. |24 39 16|34 41 5 | 860
| | | | |
24a|G. Abu Khrug | cairn. |24 38 57|34 16 19 | 870
| | | | |
20 |G. Sufra | beacon. |24 38 42|34 4 13 | 690
| | | | |
241 |Wadi Gemal island | S. end. |24 38 38|35 10 36 | 0
| | | | |
207 |G. Nahud | N. cone. |24 35 36|34 22 14 | 662
| | | | |
* 209 |Peak in G. Hafafit | beacon. |24 35 32|34 45 22 | 744
| | | | |
* 222 |Madaret Um Gamil | „ |24 34 52|34 56 28 | 454
| | | | |
226 |G. Abu Had | summit. |24 34 12|34 36 6 | 633
| | | | |
242 |Low spur of coast | tip. |24 33 47|35 10 2 | 0
| | | | |
235 |G. Um Regeba | summit. |24 33 36|34 42 29 | 571
| | | | |
233 |G. Nahud | S. cone. |24 33 35|34 20 11 | 662
| | | | |
239 |Low spur of coast | tip. |24 28 43|35 10 58 | 0
| | | | |
247 |G. Um Suerab | summit. |24 26 50|34 42 33 | 1,024
| | | | |
231 |G. Um Sueh | „ |24 26 45|34 54 30 | 781
| | | | |
236 |G. el Abiad | „ |24 26 27|34 48 56 | 892
| | | | |
* 227 |G. Abu Hegilig | „ |24 26 16|34 58 32 | 607
| | | | |
237 |G. Um el Abbas | „ |24 26 11|34 56 33 | 697
| | | | |
232 |G. Nukheira | „ |24 25 58|34 32 53 | 876
| | | | |
73 |G. Um Goraf | cairn. |24 25 33|34 18 28 | —
| | | | |
252 |G. Durunkat | centre. |24 23 43|34 45 51 | 924
| | | | |
274 |S. end of low sandy | — |24 22 41|35 22 56 | 0
|island | | | |
| | | | |
255 |G. Um Sedri |S. peak of |24 22 0|34 41 3 | 970
| | twin. | | |
| | | | |
234 |G. el Heda | summit. |24 20 56|34 30 11 | 862
| | | | |
248 |G. Sarobi (S. peak) | „ |24 20 50|35 9 0 | 471
| | | | |
* 228 |G. Um Heshenib | beacon. |24 20 49|34 50 53 | 1,135
| | | | |
243 |G. Hefeiri | summit. |24 20 22|35 1 21 | 612
| | | | |
246 |G. Khulla | „ |24 19 43|34 38 42 | 978
| | | | |
253 |G. Tarfawi | N. end of |24 18 46|34 55 54 | 1,363
| | ridge. | | |
| | | | |
251 |G. Marasan | summit. |24 17 34|34 44 56 | 1,261
| | | | |
249 |G. Abu Ghusun | „ |24 16 1|34 58 17 | 1,389
| | | | |
245 |G. Metawit | „ |24 15 51|34 31 48 | 741
| | | | |
* 230 |G. Abu Hamamid | beacon. |24 14 41|34 47 38 | 1,747
| | | | |
250 |G. Um Usher | summit. |24 14 11|34 53 21 | 1,487
| | | | |
259 |G. Um Hasidok | „ |24 12 45|34 54 46 | 1,497
| | | | |
* 229 |G. Hamata | beacon. |24 12 17|35 0 16 | 1,978
| | | | |
258 |G. Abarun | summit. |24 11 20|34 50 18 | 1,602
| | | | |
257 |G. Abu Argub | „ |24 11 1|34 45 43 | 1,609
| | | | |
75 |G. Hamrat Mukbud | cairn. |24 9 53|34 23 17 | 890
| | | | |
254 |G. Ras el Kharit | peak. |24 9 25|35 1 55 | 1,661
| | | | |
261 |G. Khashir | summit. |24 9 14|35 4 50 | 1,565
| | | | |
262 |G. Ras el Kharit | peak. |24 9 2|35 0 28 | 1,564
| | | | |
* 256 |G. Kahfa | beacon. |24 8 18|34 38 55 | 1,018
| | | | |
* 399 |Hill near Bir Qoleib| beacon. |24 8 6|33 42 46 | 355
| | | | |
400 |Bir Qoleib |clay basin.|24 6 36|33 41 20 | 239
| | | | |
287 |G. el Anbat | summit. |24 5 12|34 54 58 | 788
| | | | |
263 |G. Mikbi | S. end of |24 4 54|35 4 49 | 1,388
| | ridge. | | |
| | | | |
276 |G. Um Huk | cairn. |24 4 41|35 15 34 | 517
| | | | |
279 |G. Um Sellim | E. peak. |24 3 52|35 9 51 | 947
| | | | |
320 |Peak N. of Berenice | summit. |24 3 41 |35 26 30 | 276
| | | | |
264 |G. Egat | peak. |24 3 40 | 35 3 32 | 1,277
| | | | |
273 |G. Egat | summit. |24 2 52 | 35 2 29 | 1,422
| | | | |
280 |G. Abu Ghalqa | cairn. | 24 1 7 |35 16 47 | 561
| | | | |
* 260 |G. Abu Gurdi | beacon. |24 0 11 | 35 5 17 | 1,562
| | | | |
288 |G. Derhib | summit. | 24 0 8 | 35 1 29 | 1,160
| | | | |
* 315 |Hill near Berenice | beacon. | 24 0 4 |35 30 37 | 196
| | | | |
268 |G. el Homur | summit. |23 58 54|34 55 16 | 731
| | | | |
289 |G. Um Gunud | cairn. |23 57 46|35 12 10 | 989
| | | | |
* 339 |Limestone hill on | beacon. |23 57 16|35 43 10 | 187
|Ras Benas | | | |
| | | | |
271 |G. Selaia | summit. |23 57 14|34 52 13 | 787
| | | | |
* 317 |Hill on Ras Benas | beacon. |23 56 40|35 39 44 | 193
| | | | |
* 316 |Limestone peak, Ras | „ |23 56 36| 35 36 9 | 189
|Benas | | | |
| | | | |
* 338 |Hill on Ras Benas | cairn. |23 56 1 |35 40 53 | 197
| | | | |
291 |G. Aidab | summit. |23 55 52|35 13 38 | 848
| | | | |
270 |Hill near G. Selaia | „ |23 55 46|34 53 58 | 623
| | | | |
* 275 |Low hill near G. | beacon. |23 55 30|34 54 37 | 563
|Selaia | | | |
| | | | |
278 |G. Geneina | peak near |23 54 56|34 47 45 | 548
| | N. end. | | |
| | | | |
336 |G. Um Maiat | N. end. |23 54 45|35 13 35 | 928
| | | | |
* 313 |Berenice Temple | beacon. |23 54 39|35 28 26 | 8
| | | | |
290 |Marwot Elemikan | summit. |23 54 14| 35 6 8 | 648
| | | | |
319 |Peak N. of G. | „ |23 54 10|35 13 55 | 870
|Kalalat | | | |
| | | | |
334 |Hill near Wadi | „ |23 53 57| 35 22 0 | —
|Mindeit | | | |
| | | | |
340 |Sheikh’s tomb at | centre. |23 53 50|35 47 13 | 3
|Ras Benas | | | |
| | | | |
341 |Tip of Ras Benas | sandy |23 53 42| 35 47 5 | 0
| | point. | | |
| | | | |
266 |G. Abu Derega | summit. |23 53 38|34 59 13 | 831
| | | | |
335 |G. Um Maiat | S. end. |23 53 34|35 14 48 | 842
| | | | |
333 |High range N. of G. | N. end. |23 53 3 | 35 15 1 | 875
|Kalalat | | | |
| | | | |
77 |G. el Nekeiba | cairn. |23 52 34|34 22 10 | 570
| | | | |
330 |Hill near Wadi | summit. |23 52 29|35 22 18 | 328
|Kalalat | | | |
| | | | |
318 |G. Um Maiat | central |23 52 24|35 15 36 | 821
| | peak. | | |
| | | | |
332 |High range N. of G. | S. end. |23 51 59|35 16 29 | 762
|Kalalat | | | |
| | | | |
331 |G. Kalalat |minor peak.|23 50 48|35 15 51 | 743
| | | | |
294 |N. end of Mukawar | — |23 50 47|35 48 31 | 0
|Island | | | |
| | | | |
293 |G. Batoga | central |23 50 7 |35 20 46 | 802
| | peak. | | |
| | | | |
329 |G. Kalalat | N. peak. |23 49 57| 35 17 6 | 1,080
| | | | |
294a|S. end of Mukawar | — |23 49 53|35 48 19 | 0
|Island | | | |
| | | | |
314 |G. Batoga (S. peak) | beacon. |23 49 37| 35 21 9 | 785
| | | | |
* 282 |G. Kalalat | „ |23 49 9 |35 17 36 | 1,125
| | | | |
328 |G. Batoga |minor peak.|23 48 57|35 22 47 | 413
| | | | |
353 |Minor peak of G. | S. one of |23 47 37|35 18 46 | 894
|Kalalat | pair. | | |
| | | | |
355 |G. Um Hegilig | summit. |23 47 13|35 14 32 | 966
| | | | |
327 |G. Dibag | NW. peak. |23 46 47|35 21 23 | 517
| | | | |
308 |G. Dibag | SE. peak. |23 46 40| 35 22 4 | 544
| | | | |
* 265 |G. Dahanib | beacon. |23 45 44|35 11 10 | 1,270
| | | | |
* 269 |G. Um Bisella | „ |23 45 34|34 57 39 | 824
| | | | |
* 277 |G. Zergat Naam | „ |23 45 28|34 40 34 | 823
| | | | |
345 |G. Reyan | N. peak. |23 45 20|35 17 50 | 740
| | | | |
346 |G. Reyan | S. peak. |23 44 7 |35 17 20 | 863
| | | | |
* 343 |Hill near Shenshef | beacon. |23 44 5 |35 22 40 | 290
|ruins | | | |
| | | | |
292 |Erf el Gemal | W. end of |23 43 37|34 52 10 | 673
| | ridge. | | |
| | | | |
272 |G. Hagar el Fil | summit. |23 43 5 | 34 42 3 | 845
| | | | |
281 |G. Shut | „ |23 42 35|35 16 59 | 930
| | | | |
398 |Bir Abu Hashim | principal |23 41 56| 34 4 26 | 320
| | well. | | |
| | | | |
* 397 |Hill near Bir Abu | beacon. |23 41 44| 34 3 33 | 386
|Hashim | | | |
| | | | |
348 |Hill near W. Salib | summit. |23 41 5 | 35 7 3 | 703
|Abiad | | | |
| | | | |
325 |G. Um Etli | central |23 39 54|35 23 22 | 795
| | peak. | | |
| | | | |
384 |G. Abu Husenat | summit. |23 39 45| 35 1 15 | 725
| | | | |
326 |G. Um Etli | W. peak. |23 39 32|35 21 52 | 844
| | | | |
324 |G. Um Etli | E. peak. |23 39 26|35 23 53 | 764
| | | | |
295 |G. Hendusi |sharp peak.|23 39 15|34 58 44 | 678
| | | | |
344 |G. Um Akra | beacon. |23 37 58|35 16 41 | 1,050
| | | | |
* 385 |Ruins of Um Eleiga | „ |23 37 20| 35 3 5 | 599
| | | | |
302 |Peak near G. Abu | summit. |23 37 16| 35 6 44 | 840
|Dahr | | | |
| | | | |
* 79 |Um Harba | beacon. |23 36 56|34 30 38 | 688
| | | | |
356 |G. Um Akra | S. peak. |23 36 35|35 16 58 | 970
| | | | |
347 |G. Hindia | summit. |23 36 27|35 13 39 | 873
| | | | |
337 |Zeberged Island | central |23 36 16|36 11 42 | 238
| | peak. | | |
| | | | |
* 267a|G. Abu Dahr | beacon. |23 36 8 | 35 5 46 | 1,131
| | | | |
305 |G. Abu Sieiyil | summit. |23 35 16| 35 1 4 | 833
| | | | |
321 |G. Faraid | peak. |23 34 8 |35 23 18 | 1,131
| | | | |
323 |G. Faraid | „ |23 33 29|35 21 50 | 1,341
| | | | |
361 |Hill S. of G. Abu | summit. |23 33 28| 35 4 42 | 912
|Dahr | | | |
| | | | |
322 |G. Faraid | highest |23 33 7 |35 22 10 | 1,366
| | peak. | | |
| | | | |
342 |G. Faraid | „ |23 31 53|35 22 46 | 1,068
| | | | |
360 |Hill S. of G. Abu | summit. |23 31 43| 35 5 15 | 772
|Dahr | | | |
| | | | |
362 |Hill S. of G. Abu | „ |23 31 37| 35 2 49 | 793
|Dahr | | | |
| | | | |
359 |Hill S. of G. Abu | „ |23 31 17| 35 6 22 | 784
|Dahr | | | |
| | | | |
* 285 |G. Faraid | peak. |23 30 53|35 20 25 | 1,259
| | | | |
* 85 |G. Um Khafur | beacon. |23 29 54|34 29 19 | 560
| | | | |
357 |G. Faraid |minor peak.|23 29 35|35 17 30 | 862
| | | | |
286 |G. Faraid | “The |23 28 58|35 20 35 | 1,232
| | Bodkin.” | | |
| | | | |
350 |G. Faraid | outlying |23 28 39|35 17 35 | 875
| | peak. | | |
| | | | |
351 |G. Faraid | peak. |23 28 35|35 16 31 | 954
| | | | |
352 |Granite peak near | summit. |23 27 48|35 13 15 | 697
|Wadi Rahaba | | | |
| | | | |
349 |G. Faraid | outlying |23 27 14| 35 19 5 | 904
| | peak. | | |
| | | | |
297 |G. Orga | beacon. |23 26 21| 35 8 17 | 682
| | | | |
363 |Hill near Wadi | summit. |23 26 18|35 12 38 | 506
|Rahaba | | | |
| | | | |
* 296 |G. Abraq | beacon. |23 25 19|34 46 48 | 667
| | | | |
365 |Hill near Wadi | summit. |23 25 2 |35 11 42 | 536
|Rahaba | | | |
| | | | |
389 |G. Faraid |minor peak.|23 24 57|35 24 42 | 585
| | | | |
358 |G. Faraid | peak. |23 22 39|35 22 19 | 916
| | | | |
395a|G. Abraq | „ |23 22 26|34 50 18 | 699
| | | | |
395 |G. Abraq | „ |23 22 19| 34 50 4 | 705
| | | | |
* 87 |G. Awamtib | beacon. |23 20 59|34 26 39 | 793
| | | | |
* 299 |G. Um Tenedba | „ |23 19 48|35 10 40 | 656
| | | | |
368 |Hill near G. Um | summit. |23 18 43|35 12 36 | 555
|Tenedba | | | |
| | | | |
* 390 |Plateau near Abu | beacon. |23 18 40|34 48 30 | 639
|Saafa | | | |
| | | | |
307 |G. Saalek | peak E. |23 18 18|34 31 10 | 753
| | side. | | |
| | | | |
* 354a|G. Fereyid | beacon. |23 17 29|35 22 48 | 612
| | | | |
394 |G. Hodein | „ |23 16 20|34 53 25 | 695
| | | | |
380 |G. Hodein | corner of |23 16 18|34 52 5 | 718
| | scarp. | | |
| | | | |
304 |Peak W. of G. Um | summit. |23 15 26|34 30 14 | 805
|Reit | | | |
| | | | |
306 |Peak W. of G. Um | „ |23 15 23|34 31 47 | 837
|Reit | | | |
| | | | |
366 |Hill near Wadi | „ |23 15 4|35 16 25 | 420
|Rahaba | | | |
| | | | |
* 300 |G. Um Reit | beacon. |23 15 4|34 34 17 | 857
| | | | |
* 298a|G. Harhagit | „ |23 14 35|35 12 52 | 542
| | | | |
393 |G. Tibatib | summit. |23 12 41|35 1 28 | 396
| | | | |
387 |Hill near Wadi | „ |23 12 24|35 16 51 | 383
|Hodein | | | |
| | | | |
396 |Granite peak near | „ |23 11 11|35 20 35 | 355
|Wadi Rahaba | | | |
| | | | |
392 |Rock in sea | (level |23 10 55|35 35 57 | 0
| | datum). | | |
| | | | |
310 |Isolated hill west | summit. |23 10 35|34 25 23 | 703
|of G. Etresia | | | |
| | | | |
388 |Hill near Wadi | „ |23 10 33|35 16 32 | 309
|Hodein | | | |
| | | | |
423 |G. Kala | „ |23 10 3|34 45 49 | 808
| | | | |
503 |G. Etresia |E. summit. |23 9 24|34 30 43 | 1,037
| | | | |
303 |Hill E. of G. | summit. |23 9 15|34 32 23 | 922
|Etresia | | | |
| | | | |
* 375a|G. Anfeib | beacon. |23 8 24|34 59 19 | 705
| | | | |
364 |Hill NE. of G. el | summit. |23 8 0|35 21 46 | 359
|Anbat | | | |
| | | | |
* 386 |Close to Bir | beacon. |23 7 57|35 36 23 | 13
|Shalatein | | | |
| | | | |
502 |G. Etresia | summit. |23 7 53|34 31 24 | 1,038
| | | | |
407 |G. Kala | „ |23 7 42|34 42 58 | 846
| | | | |
311 |Isolated hill north | „ |23 7 16|34 24 39 | 901
|of G. Shigigat | | | |
| | | | |
425 |G. Kala | „ |23 7 11|34 42 37 | 783
| | | | |
424 |G. Kala | „ |23 6 51|34 42 30 | 739
| | | | |
501 |G. Etus | „ |23 6 19|34 29 53 | 997
| | | | |
* 367a|G. el Anbat | beacon. |23 6 5|35 19 27 | 390
| | | | |
312 |G. Shigigat |conspicuous|23 5 37 |34 23 39 | 1,023
| | peak. | | |
| | | | |
406 |G. Kala | summit. |23 5 16|34 42 19 | 629
| | | | |
500 |G. Aqab el Negum | „ |23 3 26|34 27 20 | 1,149
| | | | |
496 |G. Natetiai | peak. |23 3 8|34 21 0 | 1,022
| | | | |
499 |Peak near Aqab el | summit. |23 2 43|34 26 3 | 998
|Negum | | | |
| | | | |
498 |Peak near Aqab el | „ |23 2 22|34 25 36 | 979
|Negum | | | |
| | | | |
497 |Peak near Aqab el | „ |23 1 56|34 25 42 | 974
|Negum | | | |
| | | | |
495 |G. Natetiai | peak. |23 0 49|34 22 7 | 1,164
| | | | |
373 |G. Niqrub el Tahtani| high |23 0 42|35 0 58 | 828
| | pinnacle. | | |
| | | | |
373a|G. Niqrub el Tahtani| beacon. |23 0 39|35 0 53 | 829
| | | | |
* 369a|G. Beida | „ |23 0 14|35 16 54 | 716
| | | | |
494 |G. Natetiai | peak. |22 59 35|34 22 22 | 977
| | | | |
508 |Peak in S. part of | summit. |22 58 45|34 20 29 | 885
|G. Feg | | | |
| | | | |
391 |G. Humariai | „ |22 58 38|35 9 36 | 563
| | | | |
382 |Hill S. of Wadi | „ |22 58 10|35 12 58 | 631
|Beida | | | |
| | | | |
507 |Peak in S. part of | „ |22 58 2|34 19 15 | 836
|G. Feg | | | |
| | | | |
381a|Hill S. of Wadi | „ |22 57 30|35 16 53 | 631
|Beida | | | |
| | | | |
379 |G. Mismih | „ |22 56 56|34 45 32 | 599
| | | | |
381 |Hill S. of Wadi | „ |22 56 47|35 17 3 | 615
|Beida | | | |
| | | | |
510 |Conical hill | „ |22 54 48|34 40 27 | 504
| | | | |
* 401 |G. Kolaiqo | beacon. |22 54 13|35 24 35 | 320
| | | | |
* 374 |G. Niqrub el Foqani | „ |22 51 29|34 56 49 | 1,078
| | | | |
509 |G. Waqif | summit. |22 51 21|34 38 57 | 556
| | | | |
466 |Tree at Mersa Shab | centre. |22 50 56|35 47 3 | 1
| | | | |
419 |G. Um el Kalala | N. peak. |22 50 23|34 44 14 | 672
| | | | |
506 |G. Sheyenit | „ |22 50 13|34 18 23 | 853
| | | | |
505 |G. Sheyenit | S. peak. |22 49 58|34 18 15 | 887
| | | | |
415 |G. Um el Kalala | „ |22 49 26|34 44 18 | 655
| | | | |
418 |Hill close to Bir | beacon. |22 47 46|35 1 39 | 556
|Madi | | | |
| | | | |
* 408 |G. Meneiga | „ |22 47 35|35 11 7 | 1,032
| | | | |
* 402 |G. Meneiga | highest |22 47 31|35 10 57 | 1,092
| | point. | | |
| | | | |
430 |Hill near Wadi | summit. |22 46 29|35 20 11 | 443
|Tikosha | | | |
| | | | |
* 410 |Gemeida hill | beacon. |22 46 29|35 37 49 | 123
| | | | |
437 |Hill SSE. of Bir | summit. |22 45 58|35 13 3 | 987
|Meneiga | | | |
| | | | |
434 |Peak near Wadi Ti | „ |22 44 36|35 17 54 | 774
|Ilak | | | |
| | | | |
376 |G. Shabih | highest |22 44 26|34 50 21 | 1,117
| | peak. | | |
| | | | |
527 |G. Mishbih |NW. summit.|22 44 21|34 41 23 | 1,321
| | | | |
378 |G. Mishbih | beacon. |22 44 18|34 41 20 | 1,316
| | | | |
440 |Ridge near head of |high point.|22 44 15|35 12 18 | 1,092
|W. Shellal el Gharbi| | | |
| | | | |
447 |Qrein Salama | summit. |22 44 5|35 24 32 | 354
| | | | |
435 |Peak near Wadi Ti | „ |22 44 4|35 17 46 | 849
|Ilak | | | |
| | | | |
431 |Hill N. of Wadi | „ |22 43 55|35 18 52 | 670
|Muqur | | | |
| | | | |
414 |G. el Naga | smaller |22 43 32|34 27 22 | 747
| | hill. | | |
| | | | |
91 |G. Seiga | cairn. |22 43 31|34 16 16 | 905
| | | | |
377 |G. Mishbih | E. peak. |22 43 28|34 42 39 | 1,311
| | | | |
526 |G. Mishbih | peak. |22 42 52|34 41 27 | 1,353
| | | | |
413 |G. el Naga | N. peak. |22 42 42|34 27 46 | 787
| | | | |
445 |G. Tueiwi | summit. |22 42 40|35 5 56 | 836
| | | | |
* 403 |G. Gerf |high point |22 42 15|35 11 43 | 1,339
| | on ridge | | |
| | | | |
427 |G. Gerf | minor |22 42 13|35 13 32 | 1,327
| | summit. | | |
| | | | |
* 370 |G. Gerf | beacon. |22 42 6|35 12 16 | 1,419
| | | | |
412 |G. el Naga | S. peak. |22 42 0|34 28 25 | 827
| | | | |
436 |Peak near Wadi Muqur| summit. |22 41 58|35 18 22 | 778
| | | | |
493 |G. Mishbih | S. peak. |22 41 44|34 42 41 | 988
| | | | |
432 |Peak near Wadi Muqur| summit. |22 41 40|35 17 35 | 962
| | | | |
383 |G. Muqur | „ |22 41 31|35 16 50 | 1,058
| | | | |
433 |Hill near Bir | „ |22 41 16|35 0 57 | 797
|Sararat Seyet | | | |
| | | | |
426 |Peak near Wadi | summit. |22 41 6|35 14 30 | 1,258
|Diqdib | | | |
| | | | |
438 |Peak near Wadi | „ |22 41 3|35 17 54 | 911
|Qadiloi | | | |
| | | | |
429 |Peak near Wadi | „ |22 40 51|35 9 55 | 1,227
|Eirahimib | | | |
| | | | |
371 |G. Shweib | „ |22 40 43|34 43 57 | 914
| | | | |
428 |Peak near Wadi | „ |22 40 38|35 10 29 | 1,327
|Eirahimib | | | |
| | | | |
531 |Mt. near Bir Baaneit| „ |22 40 1|35 18 15 | 909
| | | | |
404 |G. Gerf | minor |22 39 59|35 10 7 | 1,318
| | summit. | | |
| | | | |
405 |G. Korabkansi | „ |22 39 39|35 0 44 | 1,052
| | | | |
446 |G. Korabkansi | N. peak. |22 39 35|34 59 32 | 1,176
| | | | |
614 |G. Hamra Dom | „ |22 39 34|35 38 19 | 326
| | | | |
439 |Peak near Wadi | summit. |22 39 17|35 16 11 | 1,028
|Diqdib | | | |
| | | | |
* 372 |G. Korabkansi | beacon. |22 39 16|34 59 55 | 1,230
| | | | |
420 |Peak near Wadi | cairn. |22 39 11|35 10 21 | 1,298
|Difoteb | | | |
| | | | |
* 417 |G. Hamra Dom | beacon. |22 39 6|35 38 42 | 388
| | | | |
450 |Tibansi Tikam Ankwei| summit. |22 39 5|35 32 11 | 345
| | | | |
475 |Peak near Wadi | „ |22 38 20|35 11 42 | 1,344
|Sherefa | | | |
| | | | |
411 |G. Hamra Dom | central |22 38 2|35 39 12 | 381
| | peak | | |
| | | | |
473 |Hill near Wadi Um | summit. |22 37 54|35 17 56 | 926
|Saha | | | |
| | | | |
532 |Hill near Wadi Um | „ |22 37 53|35 17 56 | 932
|Saha | | | |
| | | | |
444 |G. Dreb | peak. |22 36 54|35 6 20 | 1,139
| | | | |
615 |G. Hamra Dom | S. peak. |22 36 48|35 39 36 | 317
| | | | |
443 |G. Dreb | peak. |22 36 41|35 7 0 | 1,148
| | | | |
442 |G. Dreb | „ |22 36 40|35 7 46 | 1,137
| | | | |
476 |G. Dreb | „ |22 36 16|35 9 15 | 1,176
| | | | |
478 |G. Dreb | „ |22 36 10|35 8 21 | 1,224
| | | | |
477 |G. Dreb | „ |22 36 1|35 8 56 | 1,191
| | | | |
504 |G. Kulyeit | summit. |22 35 50|34 16 38 | 724
| | | | |
441a|G. Dreb | peak. |22 35 18|35 8 24 | 1,293
| | | | |
533 |Kilia Arib | summit. |22 35 2|35 18 46 | 647
| | | | |
441 |G. Dreb | peak. |22 35 0|35 8 36 | 1,288
| | | | |
535 |G. Dreb | „ |22 34 15|35 9 42 | 1,095
| | | | |
534 |Tibashoi Tomakolat | summit. |22 33 4|35 19 40 | 464
| | | | |
* 449a|Kolmanab hill | beacon. |22 32 26|35 53 36 | 137
| | | | |
566 |Hill near Wadi Ibib | summit. |22 32 2|35 37 36 | 459
| | | | |
619 |Point near Kolmanab | — |22 31 55|35 52 40 | 110
| | | | |
612 |G. Medarai |minor peak.|22 31 23|35 13 5 | 1,103
| | | | |
520 |G. Medarai | summit. |22 30 58|35 12 5 | 1,299
| | | | |
610 |G. Medarai |minor peak.|22 30 56|35 14 37 | 922
| | | | |
485 |G. Anweiyib |N. summit. |22 30 22|34 53 42 | 871
| | | | |
* 567a|G. Eqrun (W. summit)| beacon. |22 30 10|35 37 9 | 473
| | | | |
567 |G. Eqrun |SE. summit.|22 30 0|35 37 18 | 468
| | | | |
665 |Adar Aweib Um | summit. |22 29 28|35 33 2 | 455
|Bishtit | | | |
| | | | |
577 |Granite hill | „ |22 29 19|35 54 6 | 143
| | | | |
522 |G. Medarai | S. peak. |22 29 8|35 12 4 | 1,114
| | | | |
528 |G. Anweiyib | summit. |22 29 5|34 53 32 | 864
| | | | |
587 |G. Um Rasein | N. peak. |22 28 52|35 20 44 | 791
| | | | |
* 416 |G. Um Rasein | beacon. |22 28 12|35 20 19 | 909
| | | | |
* 575 |Einiwai hill | „ |22 27 50|35 57 59 | 138
| | | | |
521 |G. Abu Hireiq |N. summit. |22 27 39|35 14 58 | 1,116
| | | | |
609 |Hill near Wadi | summit. |22 27 21|35 15 51 | 856
|Merdiyeb | | | |
| | | | |
613 |Tahaqayet | „ |22 26 47|35 40 23 | 432
| | | | |
596 |Hill near Wadi Odruk| „ |22 26 47|35 18 42 | 639
| | | | |
595 |Hill near Wadi Odruk| „ |22 26 25|35 19 17 | 615
| | | | |
582 |Granite hill | „ |22 26 23|35 56 20 | 155
| | | | |
592 |Near Wadi Odruk | peak. |22 26 9|35 20 9 | 627
| | | | |
523 |G. Abu Hireiq | highest |22 25 57|35 14 39 | 1,319
| | point. | | |
| | | | |
581 |Osnei hill | summit. |22 25 38|35 50 42 | 251
| | | | |
455 |Hill near Bir Um | „ |22 25 14|35 33 19 | 634
|Bishtit | | | |
| | | | |
472 |Mt. near Wadi Abu | „ |22 24 43|35 16 13 | 1,256
|Hireiq | | | |
| | | | |
611 |G. Adatalob Hadal | beacon. |22 24 38|35 48 22 | 381
| | | | |
451 |Titailibab | summit. |22 24 32|35 38 52 | 593
| | | | |
459 |G. Orgem | NW. peak |22 24 31|35 31 1 | 779
| | | | |
576 |G. Orgem | SE. peak. |22 24 21|35 31 11 | 775
| | | | |
488 |G. Anweiyib |NW. summit.|22 24 16|34 49 46 | 884
| | | | |
471 |Mt. near Wadi Abu | summit. |22 23 56|35 16 41 | 1,226
|Hireiq | | | |
| | | | |
486 |G. Anweiyib |SE. summit.|22 23 37|34 51 25 | 921
| | | | |
664 |Hill S. of | summit. |22 23 26|35 39 5 | 554
|Titailibab | | | |
| | | | |
422 |G. Abu Hodeid | beacon. |22 23 18|35 14 9 | 1,482
| | | | |
572 |G. Adatalob Adara | summit. |22 23 1|35 49 58 | 385
| | | | |
603 |Near Wadi Tikraneib | peak. |22 22 57|35 18 38 | 732
| | | | |
454 |G. Meis-heit-ar | summit. |22 22 37|35 34 44 | 717
| | | | |
470 |Mt. near Bir Abu | „ |22 22 31|35 17 33 | 1,074
|Hodeid | | | |
| | | | |
479 |G. Mansur Diab | „ |22 22 28|35 10 49 | 1,091
| | | | |
469 |Mt. near Bir Abu | „ |22 22 10|35 17 51 | 1,078
|Hodeid | | | |
| | | | |
457 |Hill near head of | „ |22 22 3|35 32 42 | 738
|Wadi Qidmib | | | |
| | | | |
583 |G. Tishushi Tiboki | minor |22 22 0|35 57 12 | 284
| | summit. | | |
| | | | |
647 |Abu Hodeid Oqla | summit. |22 21 29|35 17 51 | 992
| | | | |
492 |G. Um el Tiur el | „ |22 21 26|34 34 46 | 783
|Tahtani | | | |
| | | | |
666 |G. Meis-heit-ar | „ |22 21 15|35 34 48 | 721
| | | | |
580 |G. Tishushi Tiboki | highest |22 21 14|35 55 46 | 359
| | point. | | |
| | | | |
* 569a|Ti Keferiai | beacon. |22 21 0|35 49 47 | 494
| | | | |
598 |G. Hamra Tit | SW. peak. |22 20 6|35 20 44 | 642
| | | | |
461 |G. Qidmib | summit. |22 19 55|35 30 45 | 1,037
| | | | |
* 456 |O Shakafa | „ |22 19 44|35 34 42 | 751
| | | | |
597 |G. Geror |NE. summit.|22 19 31| 35 52 4 | 434
| | | | |
462 |G. Qidmib | summit. |22 19 13|35 30 23 | 1,108
| | | | |
464 |G. Qidmib | „ |22 19 4|35 29 18 | 1,070
| | | | |
463 |G. Qidmib | „ |22 18 49|35 30 15 | 1,099
| | | | |
616 |G. Geror |high point.|22 18 37|35 50 18 | 510
| | | | |
584 |G. Qidmib | summit. |22 18 18|35 29 20 | 1,089
| | | | |
453 |Adar Aqdeib | summit. |22 18 6|35 37 51 | 736
| | | | |
490 |G. Um el Tiur el | „ |22 17 56|34 41 14 | 946
|Foqani | | | |
| | | | |
602 |G. Geror | summit. |22 17 51|35 50 55 | 516
| | | | |
649 |G. el Sela | peak. |22 17 37|36 14 17 | 433
| | | | |
487 |G. Hadal Derqa | summit. |22 16 40|35 9 55 | 1,108
| | | | |
* 460 |Hadal Aweib Meisah | beacon. |22 16 39|35 31 55 | 1,224
| | | | |
650 |G. el Sela | peak. |22 16 32|36 12 59 | 560
| | | | |
491 |G. el Adraq | summit. |22 16 22|34 35 3 | 770
| | | | |
421 |Qara Saba | „ |22 16 7|35 41 34 | 778
| | | | |
601 |G. Um Seleim | „ |22 15 58|35 21 35 | 1,098
| | | | |
480 |G. Hadal Derqa | SE. peak. |22 15 50|35 10 59 | 1,090
| | | | |
585 |Hadal Aweib Meisah | minor |22 15 48|35 30 10 | 1,092
| | summit. | | |
| | | | |
604 |G. Leqaq | summit. |22 15 40|35 20 8 | 1,192
| | | | |
512 |G. Heianai |NW. summit.|22 14 40|35 1 30 | 1,007
| | | | |
668 |G. Hamida | minor |22 14 34|35 46 13 | 583
| | summit. | | |
| | | | |
620 |Qash Amir | beacon. |22 14 31|36 12 20 | 724
| | | | |
651 |G. Sul Hamid | highest |22 14 16|36 4 53 | 572
| | peak. | | |
| | | | |
568 |G. Balatitda | summit. |22 13 56|35 58 5 | 592
| | | | |
513 |G. Hilwit Hasium | NE. peak. |22 13 50|35 14 38 | 1,037
| | | | |
468 |G. Adar Qaqa | summit. |22 13 47|35 19 0 | 1,606
| | | | |
482 |G. Heianai |SE. summit.|22 13 41|35 3 11 | 1,256
| | | | |
618 |G. Hamida | minor |22 13 36|35 46 47 | 701
| | summit. | | |
| | | | |
608 |G. Adar Qaqa | „ |22 13 33|35 19 21 | 1,542
| | | | |
448 |G. Hamida | summit. |22 13 32|35 46 33 | 754
| | | | |
* 458 |Halaib Fort | centre of |22 13 25|36 38 56 | 8
| | top. | | |
| | | | |
556 |G. Elba | peak |22 13 21|36 22 23 | 820
| | near Bir | | |
| |Kansisrob. | | |
| | | | |
652 |Hill E. of G. | peak. |22 13 20|35 59 43 | 491
|Balatitda | | | |
| | | | |
555 |Karam Elba | summit. |22 13 13|36 25 40 | 586
| | | | |
525 |G. Shanaiyet | „ |22 13 4|34 49 43 | 907
| | | | |
653 |Hill near Wadi | „ |22 13 4|35 50 12 | 511
|Warabeit | | | |
| | | | |
676 |G. Elba | peak near |22 13 2|36 20 54 | 935
| | Wadi | | |
| | Yahameib. | | |
| | | | |
662 |G. Balatitda | minor |22 12 56|35 57 44 | 493
| | summit. | | |
| | | | |
489 |G. el Hateib | summit. |22 12 44|34 43 18 | 854
| | | | |
674 |Hill near Wadi | summit. |22 12 42|36 13 10 | 507
|Siamtit | | | |
| | | | |
516 |G. Hilwit Hasium | SW. peak. |22 12 30|35 13 14 | 952
| | | | |
669 |Mt. south of Hadal | summit. |22 12 21|35 30 40 | 1,072
|Aweib Meisah | | | |
| | | | |
481 |G. el Arib | „ |22 12 15|35 8 32 | 1,112
| | | | |
579a|G. Um Ein | beacon. |22 11 52|35 39 4 | 901
| | | | |
667 |Hill near head of | summit. |22 11 40|35 47 6 | 651
|Wadi Warabeit | | | |
| | | | |
467 |G. Soaorib | „ |22 11 33|35 20 13 | 1,469
| | | | |
* 536 |G. Elba | beacon. |22 11 27|36 20 52 | 1,428
| | | | |
621 |G. Elba |minor peak.|22 11 16|36 23 44 | 1,102
| | | | |
675 |G. Elba | „ |22 11 10|36 20 35 | 1,394
| | | | |
483 |G. Heleikonti | summit. |22 11 7|34 57 59 | 1,151
| | | | |
573 |G. Warabeit | „ |22 11 1|35 47 52 | 794
| | | | |
518 |G. Soaorib | „ |22 10 54|35 17 48 | 1,397
| | | | |
* 571 |Adar Aweib | beacon. |22 10 50|35 54 0 | 620
| | | | |
538 |G. Elba |minor peak.|22 10 17|36 19 34 | 1,217
| | | | |
606 |G. Soaorib | summit. |22 10 14|35 21 25 | 1,349
| | | | |
98 |G. Muqsim | cairn. |22 10 11|34 1 12 | 825
| | | | |
589 |Mt. near Wadi | summit. |22 10 10|35 30 45 | 1,266
|Baueiwai | | | |
| | | | |
537 |G. Elba | highest |22 10 3|36 21 52 | 1,435
| | point. | | |
| | | | |
617 |G. Mashushenai | summit. |22 9 54|35 49 45 | 634
| | | | |
605 |G. Soaorib | peak. |22 9 50|35 21 45 | 1,383
| | | | |
678 |G. O Sir Eirab | summit. |22 9 24|36 20 56 | 842
| | | | |
677 |Hill near W. O Sir | „ |22 9 7|36 15 56 | 724
|Hadal | | | |
| | | | |
519 |Peak near Wadi Kirir| „ |22 8 24|35 18 27 | 1,328
| | | | |
465 |G. Soaorib | „ |22 8 22|35 23 36 | 1,431
| | | | |
590 |Mt. N. of Wadi Adar | NE. peak. |22 8 16|35 31 2 | 1,294
|Ameit el Sharqi | | | |
| | | | |
670 |Hill near Wadi Aqwem| summit. |22 8 12|35 43 30 | 724
| | | | |
578 |Hill near Da-aiyob | „ |22 7 45|35 44 8 | 833
|Wushaq | | | |
| | | | |
681 |G. Hanquf |minor peak.|22 7 45|36 16 54 | 789
| | | | |
591 |Mt. N. of Wadi Adar | SW. peak. |22 7 12|35 29 54 | 1,299
|Ameit el Sharqi | | | |
| | | | |
682 |G. Hanquf |minor peak.|22 6 54 |36 17 18 | 877
| | | | |
524 |G. Um Reddam | summit. |22 6 23|34 59 55 | 1,109
| | | | |
657 |G. Miatit | W. peak. |22 6 14|35 34 12 | 1,229
| | | | |
511 |Mt. near G. Egat | summit |22 5 53|34 53 1 | 985
| | | | |
484 |G. Egat | „ |22 5 39|34 52 15 | 1,145
| | | | |
586 |G. Miatit | SE. peak. |22 5 36|35 35 34 | 1,257
| | | | |
659 |Mt. near Wadi Adar | peak. |22 5 20|35 25 30 | 1,440
|Ameit el Gharbi | | | |
| | | | |
540 |G. Hanquf | N. peak. |22 4 52|36 18 45 | 1,397
| | | | |
452 |Hill near W. Di-ib | summit. |22 4 14|36 1 32 | 491
| | | | |
655 |G. Suruk | E. peak. |22 4 10|35 38 7 | 1,059
| | | | |
588 |G. Suruk | highest |22 3 50|35 35 28 | 1,327
| | point. | | |
| | | | |
673 |Hill near G. Suruk | peak. |22 3 46|35 40 16 | 846
| | | | |
656 |G. Shendib | „ |22 3 40|35 36 1 | 1,275
| | | | |
515 |Mt. near G. Himeitra| „ |22 3 17|35 17 52 | 1,134
| | | | |
685 |G. Shendib | „ |22 3 8|36 13 44 | 1,427
| | | | |
539 |G. Shendodai | highest |22 3 1|36 25 31 | 1,529
| | peak. | | |
| | | | |
672 |Hill near G. Suruk | peak. |22 3 0|35 40 25 | 847
| | | | |
661 |G. Shiab | „ |22 2 57|35 45 18 | 855
| | | | |
* 607 |G. Hadarba | beacon. |22 2 53|36 47 23 | 217
| | | | |
654 |G. Shiab | highest |22 2 51|35 44 7 | 987
| | point. | | |
| | | | |
517 |G. Himeitra | summit. |22 2 46|35 14 19 | 1,231
| | | | |
474 |G. Is | cairn on |22 2 36|35 28 4 | 1,736
| | summit. | | |
| | | | |
599 |G. Is | peak. |22 2 24|35 27 35 | 1,659
| | | | |
627 |G. Shendodai | S. peak. |22 2 12|36 25 22 | 1,395
| | | | |
684 |Hill near G. Shendib| summit. |22 2 12|36 9 6 | 601
| | | | |
600 |G. Is | peak. |22 2 11|35 26 56 | 1,594
| | | | |
671 |Hill near G. Suruk | „ |22 1 54|35 40 20 | 903
| | | | |
593 |Mt. east of G. Is | N. peak. |22 1 38|35 31 56 | 1,290
| | | | |
570 |G. Hanquf | highest |22 1 32|36 20 14 | 1,465
| | point. | | |
| | | | |
640 |G. Shendib | peak. |22 1 26|36 14 47 | 1,724
| | | | |
641 |G. Shendib | „ |22 1 8|36 14 59 | 1,698
| | | | |
594 |Mt. east of G. Is | S. peak. |22 1 2|35 31 11 | 1,474
| | | | |
642 |G. Shendib | peak. |22 0 51|36 15 0 | 1,696
| | | | |
543 |G. Shendib | beacon. |22 0 48|36 16 30 | 1,912
| | | | |
546 |G. Shendib | peak. |22 0 46|36 14 49 | 1,674
| | | | |
544 |G. Shendib | peak. |22 0 45|36 16 10 | 1,852
| | | | |
687 |Hill near G. Shellal| summit. |22 0 40|36 9 2 | 614
| | | | |
557 |G. Shellal | peak. |22 0 39|36 30 30 | 1,269
| | | | |
529 |G. Shellal | E. peak. |22 0 34|36 30 45 | 1,279
| | | | |
574 |G. Shellal | highest |22 0 15|36 29 40 | 1,409
| | point. | | |
| | | | |
545 |G. Shendib | peak. |21 59 56|36 17 6 | 1,863
| | | | |
547 |G. Shendib | „ |21 59 49|36 15 42 | 1,668
| | | | |
550 |G. Shendib | „ |21 59 8|36 14 16 | 1,565
| | | | |
645 |G. Shendib | „ |21 59 7|36 13 22 | 1,227
| | | | |
549 |G. Shendib | „ |21 59 6|36 14 40 | 1,525
| | | | |
644 |G. Shendib | „ |21 59 0|36 15 20 | 1,552
| | | | |
646 |G. Shendib | „ |21 58 58|36 13 11 | 1,196
| | | | |
660 |Low hill near W. | summit. |21 58 24|36 4 25 | 500
|Shendib | | | |
| | | | |
541 |G. Qeda | E. peak. |21 56 24|36 28 11 | 1,850
| | | | |
542 |G. Qeda | W. peak. |21 56 16|36 26 12 | 1,872
| | | | |
514 |Hadal Aweib | summit. |21 52 40|35 22 26 | 1,780
| | | | |
628 |G. Asotriba | highest |21 51 55|36 30 26 | 2,216
| | point. | | |
| | | | |
551 |Eir Aweit | peak. |21 50 30|36 22 48 | 1,715
| | | | |
552 |Eir Aweit | „ |21 49 56|36 23 1 | 1,678
| | | | |
564 |G. Obkeik | N. peak. |21 49 55|35 39 40 | 1,837
| | | | |
548 |G. Asotriba | S. peak. |21 49 30|36 30 40 | 2,082
| | | | |
565 |G. Obkeik | S. peak. |21 49 6|35 39 29 | 1,856
| | | | |
553 |Eir Aweit | highest |21 47 57|36 22 40 | 1,853
| | peak. | | |
| | | | |
554 |Eir Aweit | peak. |21 47 38|36 22 32 | 1,759
| | | | |
658 |Adar It |sharp peak.|21 47 1|36 19 14 | 1,170
| | | | |
409 | | beacon. |21 44 21|34 36 53 | —
| | | | |
558 |Arit | peak. |21 40 26|36 22 50 | 1,529
| | | | |
559 |Arit | „ |21 39 25|36 22 32 | 1,772
| | | | |
663 |Karai Awa | summit. |21 39 18|36 10 21 | 1,056
| | | | |
562 |Arit | peak. |21 38 3|36 18 57 | 1,410
| | | | |
560 |Arit | highest |21 36 51|36 23 27 | 1,810
| | peak. | | |
| | | | |
563 |Arit |high peak. |21 36 1|36 19 52 | 1,727
| | | | |
561 |Arit | W. end of |21 35 50|36 22 48 | 1,532
| | ridge. | | |
--------+--------------------+-----------+--------+---------+---------
=Comparison of Positions determined on the Red Sea with those
previously found in Official Marine Surveys.=
It is interesting to compare the positions found for certain
triangulation points with those determined by the British
Admiralty surveyors and by Lieut. Koss, who accompanied the Austrian
research-ship “Pola” in 1895-6.[74] The three best defined points
of comparison are Berenice temple, the central peak of St. John’s
Island, and Halaib Fort. In the case of Berenice and St. John’s
Island the observation of the two prior surveys were made at stations
a little distance from my triangulation points, but the published
charts enable one to scale off the necessary corrections to reduce
the positions to those of the triangulated points. At Berenice,
the British Admiralty observation point, for which the latitude is
given as 23° 56′ 16″, is 1′ 26″ north of the temple, so
that the equivalent Admiralty latitude for the temple is 23° 54′
50″. Similarly Lieut. Koss’s observation point, where the latitude
found was 23° 56′ 27″, is 1′ 47″ north of the temple, giving
the latitude of the temple as 23° 54′ 40″. My triangulation
gives the latitude of the temple as 23° 54′ 39″, thus showing a
remarkably good agreement with that found by the “Pola” observer.
At St. John’s Island, owing to the smallness of the scale of
the available charts, it is a little more difficult to scale off
accurately the Admiralty position for the peak and the reduction
to the peak of Lieut. Koss’s point. As nearly as I can scale,
the Admiralty latitude for the peak is 23° 36′ 40″, while the
point where Lieut. Koss observed his latitude of 23° 35′ 47″,
near the south-west shore of the island, is approximately 40″ south
of the peak, giving the latitude of the peak as 23° 36′ 27″. I
found the latitude of the peak to be 23° 36′ 16″, thus again
showing as good an agreement as could be expected, having regard to
the fact that it is not easy to scale the latitude of the point much
within 10″ from the existing charts.
At Halaib Fort, the Admiralty latitude is 22° 14′ 10″, while the
“Pola” expedition found it 22° 13′ 26″, and my triangulation
gave the value 22° 13′ 25″. The close agreement between my
triangulation value and that observed by Lieut. Koss seems to prove
the Admiralty latitude of this point to be some 45″ too high.
Summarizing the latitudes of the three points for comparison we
have:—
---------------------+-----------+-----------+-------------
| Berenice |St. John’s |Halaib Fort.
| Temple. | Peak. |
+-----------+-----------+-------------
Admiralty Chart |23° 54′ 50″|23° 36′ 40″|22° 14′ 10″
| | |
“Pola” Expedition |23° 54′ 40″|23° 36′ 27″|22° 13′ 26″
| | |
Ball (Triangulation)|23° 54′ 39″|23° 36′ 16″|22° 13′ 25″
---------------------+-----------+-----------+-------------
If we make corresponding comparisons of the longitudes of these
three points, Berenice Temple, St. John’s Peak, and Halaib Fort,
we obtain much more wide divergences, as is only to be expected
from the fact that the Admiralty and “Pola” determinations were
made by transport of chronometers from Suez, which is over 500 miles
distant from Halaib.
For Berenice Temple the Admiralty longitude (obtained by applying the
scaled reduction of − 40″ to the observed longitude 35° 29′
11″ at the observation point) is 35° 28′ 31″. Lieut. Koss’s
transport of chronometers from Suez _via_ Jidda leads to a longitude
of 33° 30′ 20″ for his observation point, which lies 54″ east
of the temple; thus the “Pola” longitude for the temple is 35°
29′ 26″. My triangulation gives 35° 28′ 26″, thus agreeing
very nearly with the Admiralty value and differing by exactly 1′
from the value found by Lieut. Koss.
For St. John’s Peak, the longitude scaled from the Admiralty
Chart is 36° 10′ 20″. The observations of Lieut. Koss lead to
a longitude of 36° 12′ 38″ for his observation point, which is
about 35″ west of the peak; thus the “Pola” longitude for the
peak is 36° 13′ 13″. My triangulation gives 36° 11′ 42″,
being thus between the Admiralty and “Pola” values.
For Halaib Fort, the Admiralty longitude is 36° 37′ 3″,
while Lieut. Koss’s figures lead to the value 36° 40′ 38″;
my triangulation gives 36° 38′ 56″, thus again showing a value
between the two marine determinations.
Summarizing the longitudes obtained for the three points, we have:—
---------------------+-----------+-----------+-------------
| Berenice |St. John’s |Halaib Fort.
| Temple. | Peak. |
+-----------+-----------+-------------
Admiralty Chart |35° 28′ 31″|36° 10′ 20″|36° 37′ 3″
| | |
“Pola” Expedition |35° 29′ 26″|36° 13′ 13″|36° 40′ 38″
| | |
Ball (Triangulation)|35° 28′ 26″|36° 11′ 42″|36° 38′ 56″
---------------------+-----------+-----------+-------------
There can, of course, be no doubt of the immensely greater accuracy
of the triangulation method of determining longitude as compared
with that of chronometer transport in voyages lasting for months,
no matter how many chronometers are carried nor what care is
taken in the work. The above differences of longitude are small
when one considers that no absolute control of the chronometer of
the “Pola” expedition was obtained from October 23, 1895, when
the ship left Suez, till its return to the same port on January 27,
1896. If we examine the difference of longitude between points fairly
close together, we find rather better agreement between chronometers
and triangulation. Thus, for instance, between Berenice and Halaib,
a six days’ voyage, we have:—
--------------------+-------------+--------------
|Longitude by |Longitude by
|Chronometers |Triangulation
| (Koss). | (Ball).
+-------------+--------------
Halaib Fort | 36° 40′ 38″ | 36° 38′ 56″
| |
Berenice Temple | 35° 29′ 26″ | 35° 28′ 26″
+-------------+--------------
Difference | 1° 11′ 12″ | 1° 10′ 30″
--------------------+-------------+--------------
showing an error of only 42″, or about three seconds of time in
the six days.
The triangulation-positions:—
------------------+-------------+--------------
| Latitude N. | Longitude E.
+-------------+--------------
Berenice Temple | 23° 54′ 39″ | 35° 28′ 26″
| |
St. John’s Peak | 23° 36′ 16″ | 36° 11′ 42″
| |
Halaib Fort | 22° 13′ 25″ | 36° 38′ 56″
------------------+-------------+--------------
may therefore be taken as practically correct, and the three points
may be used as well-determined positions both for further discussion
of the “Pola” results and in further surveying expeditions in
the Red Sea.[75]
=Detail Surveying along Lines of March.=
All detail visible along lines of march from camp to camp was recorded
on plane-table sheets on a scale of 1:100,000. The usual process
was as follows: The plane-table sheet was first provided with a
graticule at 10′ intervals of latitude and longitude, and all the
triangulation points previously fixed within the area covered by the
sheet were marked in their computed places. Stations were chosen along
the route at an average distance apart of two or three kilometres,
the most commanding hills being selected, and the positions of these
were found by plane-table re-section from three or more triangulation
points. The compass, being frequently disturbed by magnetic rocks,[76]
was only used to get a first approximation to the true orientation
of the table. The plane-table station having been fixed on the map,
tacheometric readings were taken to all conspicuous points easy of
access within a radius of about two kilometres, and plotted at their
measured distances along the directions given by the alidade.
In the telemetric measurements a 5-inch tacheometer was used side
by side with the plane-table, and two staff-men were employed. As
the scale of the map was small, the sights were much longer than is
usual in tacheometry, and the maximum distance of 800 metres directly
readable by the four-metre staves employed was generally exceeded. For
the long distance readings, where the distance between two cross-wires
subtended more than the length of the staff, I devised the following
process. Bringing the centre wire to the base of the staff, a reading
of the vertical circle was taken; next, by the tangent-screw, the
wire was brought to the top of the staff, and a second reading of the
vertical circle was taken, the difference giving the angle subtended
by the four-metre staff. It is clear that the distance is as many
times greater than 800 metres, as the angle subtended is less than
17′ of arc, and the distance is thus found by simple proportion.
In the case of very long sights, even this method failed, because
the circle could only be read to half-minutes, which was too coarse
a graduation to give a good result, and in these cases the method
used was one of repetition. The wire being brought to the base of the
staff as before, and a first reading of the vertical circle taken,
the wire was brought to the top of the staff by the tangent screw,
then to the bottom again by altering the levelling screws slightly,
again to the top by the tangent screw, and so on, three or four times,
and then a second reading was taken on the vertical circle. The slight
alteration of level had no sensible influence on the result, and it
is obvious that by automatically summing up, say, four intercepts in
this way, a very much more accurate value of the subtense angle was
obtained than was possible from a single measurement. In practice
I found it was best to carry in the waistcoat pocket a card giving
the distance corresponding to any number of minutes of difference of
reading after a four-fold repetition, and it was quite practicable to
measure up to three kilometres of distance within one hundred metres
of the truth; as this only represented a millimetre on the sheet, and
as, moreover, errors were not cumulative, owing to the independent
fixation of each successive station by re-section, the accuracy was
all that could be desired, and the rapidity of measurement was very
great. In this long distance type of tacheometry, finely graduated
staves were of no use; the form of staff employed was a broad-faced
one, fifteen centimetres wide, bearing fifty-centimetre divisions
painted alternately black and white right across the whole breadth
of the staff.[77]
An average of about six or eight conspicuous points having been
telemetrically fixed from a station, the detail was sketched in around
them, and other more distant points were at the same time fixed by
plane-table intersections from several stations. At the stations the
pencil sketching of relief was by form-lines which were subsequently
replaced by hachure-rendering when inking up the sheets in camp.
Occasionally, when a high hill-station was employed overlooking a
long wadi, time was saved by reading only two distances, both in the
same wadi, one very near to the station and the other two or three
kilometres away, at the same time observing the depression-angles
to these points. The slope of the wadi being found in this way, the
depression-angles to intermediate points gave the distances of such
points without the necessity of staff reading at the intermediate
points at all. Thus, suppose the near point was close under the
station, with a distance of 500 metres and a depression-angle of 18°,
while the remote point up the wadi had a distance of three kilometres
and a depression-angle of 2° 30′. By means of a slide rule or
three-figure logarithms, the near point was found to be 163 metres
below the station, and the distant one 130 metres. A point in the
wadi estimated roughly as half way between the two would be about 146
metres below the station; so that if the observed depression-angle to
it was, say, 4° 40′, its distance would be 146/(_tan_ 4° 40′),
or 1·8 kilometres. Any possible error of preliminary estimation of
the distance in order to find the level would be without sensible
influence on the resulting true distance.
The process of traversing between stations was seldom resorted to,
as the method of fixing stations by re-section from triangulation
points is much more accurate (the errors not being cumulative)
besides being more rapid. But in certain tortuous cañon-like wadis,
where great and time-consuming climbs would have had to be undertaken
in order to see any triangulation points, the method of traversing
with the tacheometer had to be employed.
Levels along the line of march were measured trigonometrically
whenever possible; the vertical angles to one or more triangulation
points being read with the tacheometer, and the distances scaled off
the map, the differences of height, corrected for refraction, were
found by the slide rule in the same manner as in the triangulation
already described. Heights of passes and camps whence no triangulation
points were visible were determined by barometer-comparisons between
them and points of precisely determined altitude.
Names of places were written down by the guides in Arabic characters
on the spot where they were ascertained, and transliterated on the
Egyptian Government system for insertion in the map. Most of the
place-names were checked by getting the guides to give them from
several different stations.
=Detail Surveying at Occupied Triangulation Stations.=
It was generally necessary to remain for at least a week on the
mountain summits which formed the main triangulation stations,
for only on about one day in seven was the air clear enough for
sighting the beacons on the longer lines. Occasionally the entire
landscape was blotted out for ten or more consecutive days by clouds
surrounding the summit, while at other times it was possible to see
only for a limited distance round the station owing to haze. Such
times were made use of to map all visible detail within a moderate
range (say within a radius of twelve kilometres) round the station.
In this work the first stage was to find a small base, one end
of which was the station itself. Usually a minor peak of the same
range, 500 to 1,000 metres away from the station, was fairly easily
accessible, and was chosen for the other end of the base. The six-inch
theodolite being at the main station, the five-inch tacheometer was
set up at the auxiliary station, and all noteworthy hill tops, as well
as a few points along each main line of drainage, were triangulated
off this small base. The length of the base was found by including
one or two main triangulation points in the round of angles. These
minor triangles were conveniently reduced by the slide rule, and the
points plotted at once on the plane-table by means of the alidade
and the calculated distances. The base being short, it was necessary
to observe to fine marks; cracks in the rocks, and the droppings
of birds on the peaks, and the centres of selected tree trunks in
the wadis, were usually chosen. The levels of these minor points
were determined by vertical angulation in the ordinary way. Usually
about thirty points were thus fixed round each high station. Once a
number of points were fixed in the wadis, the levels of these gave
the slope, and the difference of height between any other parts of
the wadis and the station could be estimated to within a few metres by
means of the knowledge thus obtained. A sketch being now made of the
wadis, which appeared spread out almost like a map below the station,
a hundred or more points along them were selected, and their depths
below the station being very approximately known from the wadi slope,
their distances were found by observing depression angles to them
and reducing the vertical triangle by means of the slide rule on
the spot. In all, therefore, measurements were usually made of the
distances of from 100 to 200 conspicuous points in the area round
the station, and when these were plotted with the alidade on the
plane-table sheet it was not difficult to sketch in all the detail
with considerable accuracy. Usually it was not possible to see all
round the mountain from the station itself, so that subsidiary
plane-table stations near the main one were necessary. In other
cases more than one small base was measured in order to get good
angles to various points by the minor triangulation.
By the combined use of minor triangulation for peaks, and vertical
angulation for points situated along drainage lines, it was found
that far more sketching could be done in a few days at a main station
than would have been possible in the same time by tacheometric work
on the lower ground, and that of greater accuracy. More than half
of the entire detail sketching was in fact done at the main stations.
=Survey of the Coast-line.=
In the earlier portion of the work, _i.e._, north of latitude 24°,
the work on the coast-line was confined to the fixation of prominent
points such as spurs and tips of islands. Some of these were fixed
as intersected points during the triangulation, while others were
determined by observing the depression angle and azimuth to them from
trigonometrical stations of known altitude. In this latter method,
taking the mean coefficient of refraction as 0·13, the formula[78]
employed was
_d_ = 35·497 (θ − √{θ² − 11621 _h_})
where _d_ = distance in metres, θ = depression angle in seconds,
and _h_ = altitude of station in metres. This formula is rather
tedious to work out, though the work is relatively not so great if
a number of points are to be calculated from observations at the
same station. Prominent points having been fixed in this way, the
coast-line north of 24° was sketched in from the Admiralty Chart,
adjusting the longitude to fit the points fixed.
It was sometimes a little difficult, however, to identify the fixed
points on the existing charts, and hence I tried to find some
process of surveying the entire remaining coast-line _de novo_
in detail. Traversing along the coast was placed out of question
by the great expenditure of time and money which it would have
entailed. Eventually I was led to devise a new method, by which long
stretches of coast-line could be mapped by polar co-ordinates from
mountain stations with great speed and accuracy. The directions of
a series of points sufficiently close together along the coast were
taken by theodolite, and the depression angles simultaneously observed
with the vertical circle. Then, instead of computing the distances to
the points, they were plotted by a special scale graduated directly
in angles of dip; by thus doing away with all calculation at the
station, it was possible to lay down the points on the chart as
fast as the observations could be taken, usually at the rate of
four or five points a minute, and it was frequently possible to
map thirty kilometres or more of coast-line in an hour with great
accuracy. As I have given a full account of this new method in
a separate publication,[79] I shall not go into it further here,
but would refer those interested to the publication just mentioned.
With the aid of the new method the entire coast-line from just north
of Ras Benas southwards to the parallel of 22°, a distance of over
200 miles, was mapped in detail on the 100,000 scale. I had frequent
opportunities of testing the accuracy of the delineation of the coast,
both by mapping the same stretch from two widely-distant stations of
different heights, and by subsequently surveying small portions of
the coast directly by plane-table and tacheometer from triangulation
points on or near the coast; and in all cases I found the accuracy
to be very high, the differences found rarely exceeding the thickness
of a line on the map. The tides in the Red Sea are so small in range
(generally only about a metre) that variations of sea-level were
practically negligible during the operations. Bearing in mind the
great difficulties attending the survey of so inhospitable a coast
by the ordinary method of traversing, I believe the resulting outline
of the coast on my maps is very much more correct than that shown on
any previous charts. An accurate delineation of the coast-line in
this region is of course chiefly of value as indicating the extent
of land; it is of little importance to the navigator, for whom the
positions of the outlying dangerous reefs, mapped by the Admiralty
surveyors, are far more important.
=Location of the Administrative Boundary between Egypt and the Sudan.=
By an Arrêté of the Ministry of Interior issued in 1902 it was
enacted that the boundary between the administrative divisions of
Egypt and the Sudan should be as follows:—
Commencing at Bir Shalatein on the coast of the Red Sea, the limit
runs to Bir Meneiga, thence to Gebel Niqrub, thence to Gebel Um el
Tiur and to Deiga. From Deiga the line continues to Bir Esmet Omar,
thence to Gebel Bartazuga, and finally to the Nile at Korosko.
This frontier was defined after a commission had sat, at the Mudiria
of Aswân, to make enquiries as to the vested rights of the Bedouin
tribes, the guiding principle being that all Bisharin tribes should
be under Sudan administration, and all Ababda tribes (with one
exception) under the Government of Egypt. A map accompanied the
decision, but was of a very rough character, and the positions of
the points specified were not known within several miles.
Part of my work comprised the precise fixation of the points specified
in the Arrêté, with a view to laying down the boundary accurately
on a map. As was natural in the case of a boundary settled without
careful reference to the ground, certain difficulties arose in the
location. In the first place, there are two distinct Gebels Niqrub,
and two distinct Gebels Um el Tiur. I assumed the higher mountain of
each pair to be the one indicated. Secondly, the precise point of the
mountain was unspecified; I assumed the highest peak to be the point
referred to. Thirdly, the text of the Arrêté disagrees with the
map accompanying it, in that the map shows the line curved to pass
close to Gebel Mishbih, which is not mentioned in the Arrêté. I
assumed the text of the order to be determinative, and that between
the points specified the limit followed great circles on the globe,
_i.e._, practically straight lines on the map. The locality called
Deiga was not visited, and can only be approximately fixed; it
is said by guides to be a narrow road near Gebel Muqsim, of which
mountain several peaks were fixed by triangulation.
The following table gives the positions found for the various points
along the boundary from the sea to the meridian of 34° (1) from my
survey operations, and (2) as scaled from the map accompanying the
Ministerial Arrêté. A comparison of the two sets of positions will
show how much the survey has added to our knowledge of the geography
of this part of the desert.
-------------------+-----------------------+------------------------
| Latitude N. | Longitude E.
Point. +-----------------------+------------------------
| From my | From | From my | From
| Survey. |Arrêté Map.| Survey. |Arrêté Map.
-------------------+-----------+-----------+-----------+------------
Bir Shalatein |23° 8′ 5″|22° 39′ 0″|35° 36′ 28″|36° 2′ 30″
| | | |
Bir Meneiga |22° 47′ 8″|22° 41′ 30″|35° 12′ 20″|35° 2′ 30″
| | | |
Gebel Niqrub (El |22° 51′ 29″|22° 48′ 0″|34° 56′ 48″|34° 51′ 0″
Foqani) | | | |
| | | |
Gebel Um el Tiur |22° 17′ 54″|22° 18′ 30″|34° 41′ 1″|34° 32′ 0″
(El Foqani) | | | |
| | | |
Deiga (approx.) |22° 10′ 0″|22° 9′ 0″|34° 1′ 0″|34° 3′ 0″
-------------------+-----------+-----------+-----------+------------
=Variation of the Compass.=
Careful observations were made of the variation of the compass at
three stations, _viz._, Berenice Temple, Abu Saafa Springs, and near
Halaib Fort,[80] these three points being selected as being well-known
places and at the same time likely to be free from local magnetic
disturbance. Berenice is on the coast-plain where only coral and
sand occur; Abu Saafa is in a sandstone district about 100 kilometres
south-west of Berenice, and Halaib is on the calcareous and gypseous
rocks of the coast about 220 kilometres south-east of Abu Saafa.
The instrument used was a five-inch theodolite fitted with a good
trough compass. A lens was used to bring the needle accurately to
zero, and the sun or a star was employed to find the true meridian. In
each case several observations, each with an independent setting
of the needle, were made, and the mean taken. The values obtained
were:—
-------------------+---------------------------+------------------
Place. | Date and Time. |Compass-Variation
| | West.
-------------------+---------------------------+------------------
Berenice Temple |January 6, 1907, 5·30 p.m. | 2° 44′
| |
Abu Saafa Springs |October 25, 1907, 4 p.m. | 2° 37′
| |
Near Halaib Fort |May 7, 1908, 10 a.m. | 2° 18′
-------------------+---------------------------+------------------
In order to find to what degree of accuracy the results of these
determinations might be relied on, the instrument used was tested
against the Kew magnetometer at the Khedivial Observatory, Helwân,
after the completion of the work. Three observations for the
declination at Helwân gave the westerly variation as
2° 41′·2
2° 58′·8
2° 55′·0
--------
Mean 2° 55′·0
--------
while the true declination as given by the Kew magnetometer at the
same time was 2° 52′ 5″. Thus it appears reasonable to believe
the observed values to be within about 5′ of the truth.
It is rather curious to note that the declination observed at Abu
Saafa is less than that at Berenice, which lies further east, even
if allowance is made for the secular change in the interval. The
difference from what one would expect is, however, possibly owing to
errors of observation of the magnitude above-mentioned, or it may be
due to a slight local influence of magnetic rocks underground at Abu
Saafa, where the ground is near to the base of the Nubian sandstone
beds, which rest presumably on eruptive and metamorphic rocks.
It is interesting to compare the observations of declination at
Berenice and Halaib with those recorded by ROSSLER[81] at the same
places in 1895. Thus we have:—
----------------------------------+----------------------------------
Berenice. | Mersa Halaib.
------------------------+---------+-----------------------+----------
Rossler, Nov. 27, 1895 |3° 54′ |Rossler, Nov. 18, 1895 |3° 36′
| | |
Ball, Jan. 6, 1907 |2° 44′ |Ball, May 7, 1908 |2° 18′
+---------+ +----------
Diff. in 11·1 years|1° 10′ | Diff. in 12·5 years|1° 18′
| | |
Yearly decrease| 6′·3 | Yearly decrease| 6′·3
------------------------+---------+-----------------------+----------
We thus arrive at a yearly secular diminution of declination of
6′ 3″, confirming the value arrived at by Mr. KEELING[82] for
the rate of secular change in the Red Sea area from a comparison of
other observations. It may be therefore concluded that the rate of
3′ per annum given in the “Admiralty Pilot”[83] is only about
half the true value.
Travellers in the Eastern Desert should exercise care in the reliance
they place on compass bearings. Bearings taken with a compass are
generally normal in granite and sandstone country; but wherever dark
igneous and metamorphic rocks abound, disturbances are likely to
occur. Local deviations of 5° to 10° are quite common, and in some
serpentine areas even 40° of disturbance may be observed. In some
places, one can deflect the needle through a large angle by means
of a fragment of the rock no larger than a nut, so rich are some of
the basic rocks in magnetic minerals. Some lumps of rock even show
strong polarity, attracting or repelling the north pole of the needle
according as one part or another of the lump is presented to it.
* * * * *
[Footnote 62: This measurement was made in conjunction with
Messrs. Villiers Stuart, Charteris Stewart, and Clarke.]
[Footnote 63: The logarithms A′, B, and C are taken from
Merriman’s _Precise Surveying and Geodesy_, 1899, 255. p.]
[Footnote 64: CHAUVENET (_Spherical and Practical Astronomy_, Vol. I,
p. 283) shows that when both latitude and time are required, the three
stars should differ in azimuth by 120° to give the most accurate
results. But when only the latitude is required the stars are best
selected near to the meridian north and south of the zenith. This
is evident by considering that if two stars could be observed to
culminate at the same altitude on opposite sides of the zenith,
the latitude would be precisely determined independently of any
reference to time.]
[Footnote 65: I am indebted to Mr. B. H. Wade, of the Survey
Department, for drawing my attention to this method.]
[Footnote 66: The signs of the coefficients follow from those of
the trigonometrical functions; but it is useful to remember that the
coefficient of _d_φ is + or − according as the star is north or
south, while that of _dT_ is + or − according as the star is east
or west of the meridian.]
[Footnote 67: CHAUVENET, _Astronomy_, Vol. I, p. 283.]
[Footnote 68: In this connexion it is interesting to note that as the
general level of the country to the south of Gebel Um Heshenib is some
250 metres higher than that to the north of it, the plumb-line will
be deflected to the south by local attraction, thus explaining why
the observed latitude at that station exceeds by so much the value
calculated from the triangulation. Berenice temple, on the other
hand, is on a coast-plain remote from mountains, and the observed
latitude agrees closely with the calculated one.]
[Footnote 69: The method of observation and reduction was that usually
described in text books of field astronomy. _See_, for instance,
Michie and Harlow’s _Practical Astronomy_, 1902, pp. 161-168,
and the tables on pp. 198-201 of the same work.]
[Footnote 70: The Sudan Survey’s positions are all south-east of
those which I obtained for the same points.]
[Footnote 71: For calculations of this type and for tacheometric
and other reductions in the field, the Nessler “Universal” slide
rule, which is specially designed for surveyors, was found to be a
most valuable time-saver. _See_ my paper in the _Cairo Scientific
Journal_, “On the Use of the Slide-rule in Surveying,” Dec. 1907.]
[Footnote 72: A careful discussion which I have recently undertaken
of the entire series of reciprocal observations made during the three
seasons’ work shows that _k_ varies according to the altitude of
the lines and according as the lines pass over land or sea. I hope
later to publish a separate account of this discussion, which has an
important bearing on the vertical distribution of temperature in the
air. But I may here state that for overland lines the formula _k_ =
0·1503 + 0·0000164 (_h_ − 830), where _h_ is the mean altitude
of the line in metres, gives a good agreement with the observations;
while on oversea lines at altitudes above 100 metres _k_ is always
very near to 0·135. The errors in the resulting altitudes of
intersected points due to the uniform employment of _k_ = 0·13,
are very trifling, and will seldom exceed one or two metres; for
example, at a distance of thirty kilometres the substitution of _k_
= 0·16 for _k_ = 0·13 will only change the altitude by two metres.]
[Footnote 73: This number 1210 represents the significant figures
of √{106·84}, 6·84 metres being the correction given by (1 −
_k_)/2_r_ _d_² for a distance of ten kilometres.]
[Footnote 74: _Berichte der Commission für Oceanographische
Forschungen_, Sechste Reihe, Wien, 1898, pp. 13, 14.]
[Footnote 75: In particular, the adoption of the above three
longitudes as of equal accuracy with Suez will lead to a better
longitude for Jidda. The longitude of Jidda is at present fixed only
by chronometer transport from Suez, a distance of some 650 miles; but
by regarding Halaib as a fixed point the distance of comparison can
be reduced to 150 miles. The data for this revision of the longitude
of Jidda already exist in the Reports of the “Pola” expedition,
and the discussion is certainly worth undertaking before any future
surveys are conducted in the central portion of the Red Sea.]
[Footnote 76: The disturbance of the needle was of course most
frequent in the areas where dark igneous and metamorphic rocks
prevailed; in these regions disturbances of 10° were very frequent,
and in some cases, as for example on the serpentine deposits of
Sikait, as much as 40° was noticed. In the sandstone areas no
disturbances were marked.]
[Footnote 77: I have given a somewhat fuller account of this
process in a little paper on “Long-distance Tacheometry.” _Cairo
Scientific Journal_, Vol. IV, February 1910.]
[Footnote 78: JORDAN, _Handbuch der Vermessungskunde_. Stuttgart,
1897. Bd. II, p. 522.]
[Footnote 79: _A New Method of Coast Surveying_, Survey Department
Paper, No. 21. Cairo, 1911.]
[Footnote 80: The observations at Halaib were made at a point far
enough from the fort to avoid any chance of disturbance by the iron
rails which form part of the building.]
[Footnote 81: _Berichte der Commission für Oceanographische
Forschungen_, Sechste Reihe. Wien, 1898. pp. 221, 223.]
[Footnote 82: _Magnetic Observations in Egypt_, 1895-1905, Survey
Dept. Paper, No. 6. Cairo, 1907. p. 18.]
[Footnote 83: _Red Sea and Gulf of Aden Pilot._ 5th
edition. 1900. p. 7.]
CHAPTER IV.
* * * * *
=THE WADIS DRAINING WESTWARDS TO THE NILE.=
* * * * *
It has been already mentioned (p. 21) that all the drainage westward
from the main watershed ultimately reaches the Nile by the three
great trunk Wadis Shait, Kharit, and Alaqi. In the present chapter
a detailed description will be given of those parts of these
wadis and their tributaries which are known within the area under
discussion. The following scheme shows the relations of the principal
tributaries, important feeders of the tributaries themselves being
indicated in (brackets):—
{ Wadi Dweig.
{
WADI SHAIT { Wadi Muelih (Wadi Gerf, Rod el Ligah, Wadi Sibrit).
{
{ Wadi Hamish.
{ Wadi Hilgit (Wadi Um Hasidok, Wadi Um el Tiur).
{
{ Wadi Egat.
{
{ Wadi el Anbat.
{
{ Wadi Abarun.
{
{ Wadi Um Daba.
{
{ Wadi Abu Argub.
{
{ Wadi Safihat.
{
{ Wadi Um Sellim.
{
{ Wadi Medsus.
{
WADI KHARIT { Wadi Abu Gurdi.
{
{ Wadi Elemikan (Rod el Geneina).
{
{ Wadi Abu Hashim.
{
{ Wadi Helie.
{
{ Wadi Abu Hamamid (Wadi Marasani, Wadi el Sheikh).
{
{ Rod el Kharuf (Wadi Abu Had).
{
{ Wadi Khashab (Wadi Metawit, Wadi Antar).
{
{ Wadi Garara (Wadi el Kreim, Wadi Timsah, Wadi Ghadrib,
{ Wadi Abu Hashim, Wadi Abu Homur).
{
{ Wadi Natash.
{ Wadi Himeitra.
{
{ Miti Kwan (Wadi Duag, Wadi Kirir, Wadi Merau, Wadi
{ Miaus).
{
{ Wadi Dageina.
{
{ Wadi Alfawi.
{
{ Wadi Egat (Wadi Hiteib).
{
{ Wadi Hateib (Wadi Suhin).
{
WADI ALAQI { Wadi Guqub.
{
{ Wadi Um Teneideb.
{
{ Wadi Defeit (Wadi Sarid, Wadi Dauriai, Wadi Hamida,
{ Wadi Bint el Feqoh, Wadi Anweiyib, Wadi Meladoyeb, Rod
{ Hawanin, Wadi Bagharid).
{
{ Wadi Eleifat.
{
{ Wadi Seiga (Wadi Um Derera, Wadi Abu Had, Wadi Um
{ Gholqa).
Most of the drainage-lines mentioned in the description will be found
marked on the orographical map which forms Plate I; but the scale
of that map is too small for all the minor feeders to be indicated
with clearness.
=Wadi Shait=, an important main trunk wadi draining westwards to the
Nile, originates at the west foot of Gebel Ras Shait, in lat. 24°
50′, long. 34° 31′, and joins the Nile Valley a little to
the north of Kom Ombo. It has a total length of very nearly 200
kilometres, and an average fall of three metres per kilometre. The
fall is much more rapid in the upper reaches than lower down; in the
first fifty-five kilometres of its length, from the foot of Gebel
Ras Shait to Bir Um Gubur, the fall is 340 metres, or an average
gradient of six metres per kilometre, while from Bir Um Gubur, for
the remaining 140 kilometres of its course, its fall is only 250
metres, or an average gradient of less than two metres per kilometre.
The head of Wadi Shait is formed by the union of a number of
drainage channels from a kind of _cul-de-sac_ formed by Gebels
Migif, Ras Shait, and Mudergeg, where it is separated from the heads
of Wadi Gerf and Wadi Hafafit by flat sandy divides. Passing in a
south-westerly direction to the west of Gebel Migif and Gebel Dweig,
it receives as a tributary =Wadi Dweig= (in which are the ruins of an
ancient station) on the left. Taking thence a more westerly course it
traverses more open country, and then narrows among hills north-west
of the remarkable peak of Gebel Abu Khrug. At a bend further on is
=Bir Murra=, a shallow well sunk in the alluvium of the wadi floor
at the foot of a serpentine scarp; the water here (as the name of
the well indicates) is very bitter, and is generally drunk only by
camels. After passing Bir Murra, the wadi turns south-west, then
curves again near =Bir Um Gubur=, about three kilometres south-east
of Gebel Sufra, and about twelve kilometres below Bir Murra. Bir Um
Gubur is a shaft about two and a half metres diameter, sunk about
eight metres deep in the alluvium of the wadi; it was yielding good
supplies of excellent water in 1906. About ten kilometres below Bir
Um Gubur, =Wadi Hamish= joins Wadi Shait from the north-east. In the
remainder of the course of Wadi Shait to the Nile, the principal
water source is =Bir Heliwat=,[84] about ten kilometres below the
point of influx of Wadi Hamish, and the chief tributary wadis are
Muelih, Beza, and Midrik, all of which join it from the north-east.
The upper portions of Wadi Shait contain a fair abundance of trees
and scrub, but the lower parts are sandy arid wastes.
=Wadi Muelih= originates in the mountain called Gebel Iteima,
in lat. 25° 8′. For about sixteen kilometres its course lies
ill-defined over a sandy plain with scattered low hills, to Erf el
Fahid, a remarkable east and west quartz ridge nearly two kilometres
long rising among crushed diorites and schists to a height of 579
metres above sea, or ninety-five metres above the wadi, in lat. 25°
0′. After passing Erf el Fahid, the course of the wadi changes to
south-west, and gradually becomes more enclosed by low hills. The
first hills passed on the right are high ridges formed by great
quartz veins striking south-west, at the foot of which the wadi
forms a plain nearly a kilometre broad, with low hills and mounds
of dark gneisses and schists on the left. At ten kilometres below
Erf el Fahid, on the left of the wadi, is a horse-shoe shaped hill
of aplite called Marwot Rod el Ligaia, to the north and south of
which are other hills penetrated by networks of quartz veins. Two
kilometres further on, a band of diorite gneiss cuts across the wadi,
which then commences to narrow in among hills of crushed diorites,
grey gneisses, and schists, with many dykes of porphyrite and
felsite. These hills become progressively higher as one descends,
and near the meridian of 34° the wadi curves round the foot of Gebel
Muelih, a great bare white granite boss rising through darker rocks to
a height of 330 metres above the wadi, or 707 metres above sea. Just
after passing Gebel Muelih the wadi, which has here a width of only
some 200 metres, turns south-west again. At this turn, nearly in
the centre of the wadi floor, is =Bir Muelih=, an excavation about
six metres deep in the alluvium, yielding very salt water drinkable
only by camels. North-east of the well a track strikes over the hills
towards Dungash mine. From Bir Muelih the wadi continues in a roughly
south-west direction past Bir Samut (well about one kilometre north
of Wadi Muelih) and then takes a more southerly course draining into
Wadi Shait in longitude 33° 46′.
The wadi floor falls from a level of 484 metres near Erf el Fahid
to 375 metres at Bir Muelih, the length of the wadi between the two
places being about twenty-seven kilometres; this gives an average
fall of about four metres per kilometre; the actual gradient varies
from about two metres per kilometre in the broader portions to over
six metres per kilometre in the more enclosed parts of the wadi.
The upper parts of Wadi Muelih are barren and sandy, but the lower
portions contain a fair amount of vegetation. The principal feeders
of Wadi Muelih are Wadi Gerf, which enters by several openings on
the left above Gebel Muelih, Wadi Samut, entering on the right
in long. 33° 54′, and Wadi Sibrit, entering on the left in
long. 33° 50′.
=Wadi Gerf= is the collective name given to a number of rather
complicated drainage channels forming tributaries to Wadi Muelih. The
principal heads are to the east and west of Gebel Nugrus. The eastern
head is called =Wadi Hangalia=; it commences at about an altitude
of 811 metres due east of the highest point of Gebel Nugrus, at a
difficult pass leading over the main watershed to Wadi el Nom, and
curves round the north spurs of Gebel Nugrus to join the western
head. In the Wadi Hangalia are some old ruins of a mining camp,
and also some recent prospecting workings and a well giving a poor
supply of water. The Western head of Wadi Gerf commences in nearly
level ground on the main divide west of Gebel Nugrus, at an altitude
of 691 metres. These two main heads unite close to the east of Gebel
Ras Shait, whence Wadi Gerf courses about north-west through low
hills. A third head is in lat. 24° 52′, at a pass leading into
Wadi Um Khariga. A fourth, called =Rod el Atut=, takes the drainage
from all sides of the conspicuous black cone of Gebel Atut. A fifth,
called =Rod Um el Farag=, drains from the mass of moderately high
hills further west called Um el Huetat; these hills contain some old
mines, chiefly in talc schists. The drainages from these various heads
all eventually take a west-south-west course among low hills and over
a sandy plain and enter Wadi Muelih by several openings near longitude
34°. Minor tributaries are =Wadi Abu Seyal= and =Wadi Um Seyal=,
south-east of Gebel Atut, =Rod el Ligaia=, in longitude 34° 10′;
and =Rod el Ligah=, in latitude 24° 50′.
The principal hills of the plain over which Wadi Gerf and its
tributaries run their course are some very remarkable small black
peaks collectively called Khusa el Faraon, a light coloured hill
called Marwot Rod el Ligah, and a ridge called Erf el Sagur; these
two last rise to 514 and 523 metres above sea-level respectively.
Wadi Gerf possesses a fair amount of vegetation, except where it
meanders over the sandy plains; in the tributaries Wadi Um Seyal
and Wadi Abu Seyal acacia trees are specially numerous.
=Wadi Sibrit= is a long narrow wadi following a course somewhat south
of west, originating to the west of Gebel Mudergeg and joining Wadi
Muelih in longitude 33° 50′. It possesses many trees and a good
well, =Bir Sibrit=. This latter is an excavation in the wadi floor,
in longitude 33° 58′; it is said to yield a constant supply. In
the spring of 1906 I found the water was at a depth of eight metres
below the surface, and of good quality.
=Wadi Kharit=, one of the greatest trunk wadis of Egypt, has its
principal head at Gebel Ras el Kharit, on the main watershed
in latitude 14° 10′ and longitude 35°. Pursuing a course
the prevailing direction of which is a little north of west,
and collecting the drainage from numerous great wadis on its way,
it debouches on the Kom Ombo plain and reaches the Nile at the same
point as another great wadi, Shait, in latitude 24° 35′. The length
of the main channel is over 260 kilometres, and of its tributaries
probably more than twenty times as great. It drains an area of more
than 23,000 square kilometres. Its average fall is about two metres
per kilometre, but in its lower reaches its gradient is less than
half this amount.
The principal tributaries of Wadi Kharit, which will be separately
described, are the Wadis Natash, Antar, Khashab, Abu Hamamid,
Elemikan, and Garara (this last with Wadis Timsah and Ghadrib as
great feeders). I now propose to trace out the course of the main
wadi in some detail, leaving its greater tributaries for separate
description, but including its minor feeders.
The main head of Wadi Kharit is on the Nile-Red Sea divide, between
Gebel Ras el Kharit and Gebel Mikbi, at an altitude of considerably
more than 600 metres above the sea. The wadi at first courses a
little south of west, over a gently falling sandy plain with hills
of bouldery granite, and curves round the south spurs of Gebel el
Anbat.[85] Here it receives two tributaries, one from the north-west
called Wadi Hilgit, and one from the south-east called Wadi Egat.[86]
=Wadi Hilgit= originates on the main watershed in longitude 34°
52′, near Gebel Um Usher. A very steep and difficult pass over
the watershed separates its head from that of another Wadi Hilgit
draining northward to Wadi Huluz. The two wadis are called Wadi
Hilgit lil Kharit and Wadi Hilgit lil Huluz respectively when it is
necessary to distinguish them. On its course southward to Kharit,
Wadi Hilgit receives as tributaries =Wadi Um Hasidok= and =Wadi Um
el Tiur=, draining the mountains of the same names.
=Wadi Egat= drains part of the west slopes of Gebel Abu Gurdi and
the south part of Gebel Egat, for the first half of its course being
shut in by high hills and for the latter half passing over a gently
falling plain.
After passing Gebel el Anbat, Wadi Kharit continues its course a
little south of west, in broad shallow drainage channels over a great
sandy plain. In this part of its course it receives many important
feeders from the mountain masses which limit the plain to the
north. The principal of these feeders are the =Wadis Anbat=, =Abarun=,
=Um Daba=, =Abu Argub=, =Safihat=, =Um Sellim=, and =Medsus=. Near
where Wadi Medsus enters, Wadi Kharit takes a more southerly course,
passing north of a mass of low dark hills called Gebel Geneina,
and here it receives =Wadi Abu Gurdi=, draining the west slopes of
the mountain of the same name, the ill-defined Wadi Elemikan (_see_
p. 84), draining the extensive plain south of Gebel Abu Gurdi, and
the =Rod el Geneina=, draining from the hills of Geneina. A little
further on, curving to the north-west, it receives =Wadi Abu Hashim=
and =Wadi Abu Selili=, which drain the south flanks of Gebel Kahfa.
The next feeder is the =Wadi Helie=, which drains the west slopes
of Gebel Kahfa and enters Kharit from the north-east; a well, =Bir
Helie=, exists in this wadi about eight kilometres above its junction
with Kharit. The well appears to be of the same character as Bir Abu
Hamamid; it was yielding plenty of good water in the spring of 1906,
but in the autumn of the same year the supply was said to be smaller
and rather salty.
About ten kilometres below the point of influx of Wadi Helie, Wadi
Kharit receives Wadi Abu Hamamid (_see_ p. 85), coming from the
north-east, and some fourteen kilometres further on another tributary,
the =Rod el Kharuf=, enters from the opposite side conveying the
drainage from the north-west flanks of Gebel Zergat Naam.
In the remaining portion of its course to the Nile, Wadi Kharit
receives numerous other tributaries, of which the principal are Wadi
Khashab and Wadi Antar on the north, and the Wadi Garara on the south
(_see_ pp. 86 and 87).
On the whole, Wadi Kharit is poor in vegetation; trees are fairly
abundant in the central portion of its course, but both near its
head and near the river it is very barren. In consequence of its
sandy and arid character near the Nile, it is not usual for caravans
to journey along the wadi from its mouth; Arabs from Daraw usually
go up the tortuous and sandy Wadi Allawi, and thence enter Kharit
either by the Rod Abu Modellim or by a track among hills which leads
eastward to =Bir Qoleib=. Bir Qoleib is a good well in a small
tributary of Wadi Kharit, about seventy kilometres by road from
the Daraw. From Bir Qoleib to the wells of Abu Hamamid and Helie
the westward journey is about 110 kilometres, while from Bir Qoleib
to the well of Abu Hashim, south-east (on the road to Abu Saafa),
is a distance of about seventy-five kilometres.
=Wadi Elemikan= is the name given to an ill-defined system of
drainage channels meandering over the plain south of Gebel Abu
Gurdi. It originates on the main watershed, and at its head there
is a very easy pass over into the Wadi Lahami, which descends to the
sea. At this point, which is 590 metres above the sea, the watershed
is ill-defined, being a sandy plain; but while to the west the plain
continues with only a slight fall, to the east it soon gives place
to rugged country through which narrow wadis descend rapidly towards
the sea coast. The plain west of the watershed is remarkable for
the presence of three great bosses of quartz, the largest of which,
called Marwot Elemikan, rises as a conspicuous cone of dazzling
whiteness to a height of sixty-eight metres above the plain. Besides
the drainage from the plain itself, Wadi Elemikan receives feeders
from the hills which flank Gebel Abu Gurdi to the south, and also a
portion of the drainage from the Wadi Abu Gurdi, which divides into
two channels on emerging from the mountains. Passing between the
granite hills of Gebel Abu Derega and Gebel Selaia, Wadi Elemikan
courses a little north of westward over a great sandy plain to join
the Wadi Kharit north of Gebel Geneina in longitude 34° 36′. It
is a barren wadi, but water can sometimes be obtained a little north
of it at a small spring called =Megal el Selaia=, at the foot of a
low hill one kilometre south-east of the great rounded granite boss
of Gebel Selaia. I obtained a small supply of very good water here
early in 1906, but the spring is a very slow one and is said to fail
altogether in dry seasons.
=Wadi Abu Hamamid=, an important tributary of Wadi Kharit, originates
as a series of gullies in the mountains of Gebel Abu Hamamid, on the
west face of the main watershed, in longitude 34° 48′. It courses,
among high hills a little north of west to longitude 34° 41′,
then turns south-west and enters the plain which extends to the west
of Bir Shadli. Here it receives part of the drainage from Wadi el
Sheikh, and turns westward among lower hills, passing north of the
red hills called El Hamra, to Bir Abu Hamamid, and then turning
south-west between El Hamra and Hamrat Mukbud to join Kharit in
longitude 34° 23′.
=Bir Abu Hamamid= is an important well; it is a rude irregular
excavation, about six metres deep, in the wadi floor, down which
men can walk to fill their water skins. This well was yielding
more plentiful supplies in the autumn of 1906 than any of the other
wells in the neighbourhood; the water was rather salty and muddy,
but quite drinkable.
From near Bir Abu Hamamid, a track leads north-westward over the
hills to Bir Khashab and on to Bir Masur. To reach Bir Shadli,
one follows up the Wadi Abu Hamamid till it opens on to a plain,
and then strikes almost due eastward across the plain.
A small tributary which joins Wadi Abu Hamamid from the north-east,
in longitude 34° 41′, called =Wadi Marasani=, is important
as leading to a pass over the main watershed into Wadi Marasan,
a tributary of Wadi Huluz. The altitude of the pass is 685 metres
above sea; it is quite practicable for baggage camels.
=Wadi el Sheikh=, the only great tributary of Wadi Abu Hamamid,
originates in longitude 34° 40′, in the hilly tract west of Gebel
Abu Hamamid. In the upper part of its course, it is a narrow winding
wadi, mostly shut in by high hills, pursuing mainly a direction
a little west of south, fed by numerous lateral wadis entering
from among the hills to the east, of which the principal are the
=Wadis Um Somra=, =Krioni=, =Um Nasir=, =Um Hereini=, =Um Sereiha=,
=Um Deheisi=, =Um Retba=, and =Um Hargal=. Near the point where
Wadi Um Deheisi joins it, the Wadi el Sheikh emerges from the hill
country and meanders over a plain. At its entry on to the plain is
the tomb and well of =Sheikh Shadli=, views of which are given on
Plate V. The tomb, from which the wadi derives its name, is a white
domed structure, tended by a Moorish guardian. The Ababda Arabs
hold the memory of Sheikh Shadli in high veneration, and make yearly
pilgrimages to his tomb. The well, =Bir Shadli=, close to the tomb,
is a shallow excavation in the stony alluvium of the wadi floor. Here
there is a perennial supply of water, which, however, varies much in
quality and quantity; after rain, there forms a large pool of good
water, the surface being maintained almost level with the ground by
underground influx; while when there has been no rain for a year or
more the water is only found by digging to several metres depth,
and then only infiltrates slowly at the bottom of the hole, the
quality simultaneously falls off and the water acquires a saline
and purgative character.
After passing Bir Shadli and entering on the plain, Wadi el Sheikh
splits up into numerous channels, one of which joins the Wadi Abu
Hamamid, while the others continue in a south-westerly direction,
fed by the Wadis Um Retba and Um Hargal, draining from the north
flanks of Gebel Kahfa. Uniting together as they leave the plain to
re-form a single Wadi el Sheikh, these drainages turn westward among
the hills to join the Wadi Abu Hamamid.
Bir Shadli is one of the best-known centres of the Ababda
Arabs. Though there is no permanent settlement, it is seldom that many
days elapse without Arabs coming to the place to water their animals,
which graze in the adjoining wadis. Many roads converge here. To the
west, a track leads to Bir Abu Hamamid. To the north-east, a track
leads up the Wadi Sheikh, across Wadi Abu Hamamid, and by an easy
pass near Gebel Marasan over the main watershed into Wadi Huluz. To
the south-east there are several alternative routes by which one
can journey over easy passes north of Gebel Kahfa on to the plain
of Selaia and down the Wadi Lahami to Berenice. Yet another road
leads a little west of south across the Wadi Um Hargal, and by an
easy pass into Wadi Helie, a small tributary of Wadi Kharit which
drains the west side of Gebel Kahfa, and in which there is a well
of similar character to that of Abu Hamamid.
=Wadi Khashab= commences its course near Gebel el Heda, a little east
of longitude 34° 30′, and continues in a generally south-west
direction to the latitude of Gebel Hamrat Mukbud. Here it takes a
westerly course, passing south of Gebel Homr Akarim and entering
Wadi Kharit from the north in about longitude 33° 49′. Wadi
Khashab receives its name from its relatively well-wooded character;
in its upper parts it presents the appearance of a broad valley,
in which trees are so numerous as to give a very pleasing contrast
to the dreary wastes on either side of it. =Bir Khashab= is a series
of pits sunk in the wadi floor in about longitude 34° 23′, which
were yielding small supplies of water in 1906.
The principal feeders of Wadi Khashab are Wadi Metawit and Wadi
Antar. =Wadi Metawit= is a short valley originating near Gebel
Metawit, and joining Wadi Khashab a short distance above Bir
Khashab. It possesses an important well, =Bir Metawit=, excavated
about eight metres deep in the centre of the wadi floor, about three
kilometres north-north-west of the summit of Gebel Metawit, on a
road leading south-east from Bir Masur to Bir Shadli. This well,
near which are some large acacia trees, was yielding a plentiful
supply of excellent water in the spring of 1906.
=Wadi Antar= originates near the hills of Nukheira and El Heda,
and courses westward as a very wide shallow sandy depression south
of Gebel Um Goraf. At the foot of Gebel Derera it turns southward,
receiving the tributary Wadi el Anz from the left a little further
on; it turns again westward and then north-west to near Gebel Muktil,
beyond which it courses south-west and joins Wadi Khashab in longitude
33° 55′, a short distance only above the point where that wadi
enters Kharit.
=Wadi el Garara=, the great southern tributary of Wadi Kharit, heads
on the main watershed east of Gebel Um Harba. Pursuing at first
a north-westerly course over a sandy plain, it emerges between two
high sandstone hills ten kilometres north of Gebel Um Harba, and turns
somewhat more to the west, receiving the =Wadi el Kreim=, which drains
the south-east flanks of Gebel Zergat Naam. A little further on it
receives an unnamed tributary which courses north-westward from Gebel
Um Harba as a great valley nearly full of blown sand. Still further
on its course it is fed by another unnamed tributary which, coming
from the main watershed in latitude 23° 30′, courses over a wide
sandy plain north-westwards. This latter tributary is very barren,
but is of some importance as forming a very easy though sandy road
over the main watershed to the Wadi Arned (which leads to the springs
of Abu Saafa) and as passing, about five kilometres before reaching
the pass, a well known water-hole called =Galt el Aguz=. This galt
is a huge sandstone basin in the hills on the east side of the road,
fairly easy of access. After rain it holds an immense supply of water,
but owing to the porous nature of the sandstone it becomes dry in a
few months of drought; rude Greek inscriptions on the rocks, mixed
with spirited drawings of animals, show that this source of water
supply was known and used in Ptolemaic days. Besides the drainage
from the pass, the tributary first mentioned takes that from the
sandstone hills of Um Khafur situated further east.
A little lower down, Wadi Garara receives feeders from the north-east,
draining the hills round Gebel Nikeiba and Gebel Felieiti, and then
the long Wadi Timsah coming from the south.
Wadi Timsah heads among high granite hills a little north of latitude
23°, and courses in a nearly northerly direction for nearly ninety
kilometres to join Wadi Garara. The prevailing character of Wadi
Timsah itself is sandy and dreary, but its feeders from the eastern
hills are richer in vegetation, and in years when there is rain
they furnish in their upper portions good grazing ground for Arab
camels. The principal of these feeders, enumerating from the south
northwards, are the =Wadis Um el Rid=, =Awamtib= (with Wadi =Um
Marakh=), =Shabakhit=, and =Dagalai=. All these drain the western
parts of the high sandstone hills called by the same names. Water can
be got from galts here after rain. Near the head of Wadi Um el Rid,
there is a very easy pass over the main watershed into Wadi el Dreb,
which leads to the well of Um Reit.
Of the =Wadi Ghadrib=, which heads near the hills of Gebel Abu Rahia
and Gebel Um Rewat, in latitude 23°, and follows a course roughly
parallel to, but a few kilometres west of that of Wadi Timsah,
not very much is known. Its prevailing character is sandy and arid.
The small tributary called =Wadi Abu Hashim=, which enters Wadi
Garara from the south in about longitude 34° 5′, is important as
containing the important wells known as =Bir Abu Hashim=. The wells
are excavations in the alluvium of the wadi floor, and furnish good
water at a depth of about eight metres. A beacon has been erected
on a high hill to the west of the wells and overlooking them, the
position of which is latitude 23° 41′ 44″ N., longitude 34° 3′
33″ E., altitude 386 metres above sea and sixty-six metres above
the wells. The principal roads from Bir Abu Hashim are, to Aswân
(first water at Um Hibal, nearly one hundred kilometres distant), to
Daraw (first water at Bir Qoleib, seventy-five kilometres distant),
and to Abu Saafa Springs (a journey of about one hundred kilometres
with possibly water en route at the Galt el Aguz, sixty kilometres
from Abu Hashim).
=Wadi Natash= commences among the low hills forming the Nile —
Red Sea watershed between Gebel Migif and Gebel Abu Had. It pursues
a course roughly parallel with that of Wadi Shait, at first over a
sandy plain from which rise the two conspicuous cones called El Nahud
(the breasts), and afterwards narrowing in among hills. Pursuing a
somewhat devious course in a direction generally a little south of
west, Wadi Natash passes south of Gebel Nugra (in longitude 33°
40′) and enters on the great plain called Atmur Nugra, where it
joins the Wadi Kharit and drains to the Nile near Kom Ombo.
There is, I believe, no water source in Wadi Natash itself, but =Bir
Masur= is situated in a branch wadi only a few kilometres north of
it in longitude 34°. At Bir Masur there are numerous pits sunk in
the alluvium of the wadi, in one or more of which good water can
generally be found at a depth of about ten metres; but the supply
cannot always be relied on, for although I obtained plenty of water
in March 1906, I found there was only a very small quantity available
in October of the same year.
=Wadi Alaqi=, the greatest of all the Egyptian wadis draining
westwards to the Nile, has its head on the main watershed near
Gebel Is, close to the 22nd parallel in longitude 35° 27′. Its
main channel, over 350 kilometres in length, pursues a general
westerly course, winding at first, past the old mining centres of
Darahib and Alfawi, towards Gebel Muqsim, on the 34th meridian,
and then, curving round to the north of that mountain, it turns to
the north-west, past the gold mines of Um Gariart, and enters the
Nile Valley opposite the large village of Dakka, in latitude 23°
8′. The area of its basin is unknown, much of it being unexplored,
but it probably comprises no less than four square degrees of the
earth’s surface, or 44,000 square kilometres. Its heads and upper
tributaries lie among high mountainous tracts partly in Egypt and
partly in the Sudan, and occasionally the rainfall in these southern
parts of the eastern desert is sufficient to convert the usually dry
wadi into a temporary stream for a part or all of its length. That
it may on the rare occasions of sufficient rainfall discharge no
inconsiderable quantity of water into the Nile is proved by Linant’s
experience about 1830, when he records that the torrent from the
Wadi Alaqi into the Nile was so great as to prevent his _dahabîa_
sailing up the river past the point of influx, even with a good wind
and all sails set.[87] A great flow of water down the Wadi Alaqi
also occurred in the autumn of 1902 as a consequence of heavy rains
in the mountainous country east of the meridian 34° 30′. This
torrent was observed by Mr. John F. Wells, who was then manager of
the Um Gariart mine. In the early morning news was brought to the
mine that great waters were coming down the wadi. Except for a slight
rainfall at the heads of the Wadis Qoleib and Haimur, the drainage
of which did not appreciably swell the flood of the main wadi,
there had been no rain within one hundred kilometres of the mine,
and when the alarm was given, at 6.30 a.m., only a small trickling
of water down the wadi was visible, and the news was thought to
be an exaggeration. But an hour later the whole wadi was a raging
torrent, and by nine o’clock there was a mighty stream, over 300
metres wide and from one to two and a half metres deep, rushing past
the mine. The flow continued for about two and a half days. On this
occasion the stream, in spite of its magnitude at Um Gariart, did
not reach the Nile; after flowing for some seventy kilometres past
the mines, it entered a wide depression at Hagab Kara, some forty
kilometres from the mouth of the wadi, where it formed a great pool
and sank into the sand. Mr. Wells informs me that the water did not
penetrate the sandy and gravelly floor of the wadi to the bed rock
(the thickness of the sandy and gravelly layer at Um Gariart is
fourteen metres) till three months later, and then the rock, though
damp, did not absorb enough water to yield any supply to wells sunk
in it. The local Arabs stated that these downrushes of water, which
they term “seil,” occur on an average at about ten-year intervals;
the last one occurred seven years before that of 1902.
The part of the basin of Wadi Alaqi falling within the limits of the
district described in this volume includes the whole country west
of the main watershed between the parallels of 22° and 23°. This
area is drained by numerous tributaries of Alaqi, all entering the
main wadi from its north side. The following is a brief description
of these tributaries, commencing with the uppermost (easternmost)
of them.
=Wadi Himeitra= is a small wadi draining the south face of Gebel
Himeitra. It contains a well, =Bir Himeitra=, at the foot of the
mountain, which is said to yield constant supplies of water. Below
the well, Wadi Himeitra continues for about ten kilometres in
a south-westerly direction, joining the Wadi Alaqi about seven
kilometres above the ruins of Darahib.
The =Miti Kwan=, the next tributary of Alaqi, has its heads in
the north flanks of Gebel Himeitra. Near its head it receives
as feeders from the north-east the =Wadis Kirir= and =Duag=,
draining mountains of the same name which form part of the Adar
Qaqa range. About fourteen kilometres further down its course, the
Miti Kwan receives the =Wadi Merau=, which drains the hills of the
main watershed round Eir Arib. Below the point of influx of Merau,
the Miti Kwan pursues a very winding course among the hills for some
eleven kilometres, then receives from the north the =Wadi Miaus=,
a small wadi with many branches among the hills and containing a
well, =Bir Miaus=, about seven kilometres up from its mouth. After
receiving Wadi Miaus, the Miti Kwan continues a winding course for
about nine kilometres and enters the Wadi Alaqi on the 22nd parallel,
about fifteen kilometres below the ruins of Darahib. A well-known
road, connecting the Wadi Alaqi with the Abu Hodeid and Meisah wells,
leads up the Miti Kwan for a distance of some twenty-three kilometres,
and then passes northwards over a stony plain, crossing the watershed
into the head of Wadi Hasium, in which is Bir Kagog.
=Wadi Dageina= is a small many-branched tributary of Alaqi, draining
the hills east of Gebel Egat.
=Wadi Alfawi=, which enters Wadi Alaqi a little lower down its course,
is likewise a small wadi draining the hilly tract east of Gebel Egat;
there are some old mines on its western side close to its junction
with Wadi Alaqi.
=Wadi Egat=, the next important tributary of Alaqi, drains by
very numerous branches the remarkable peak of Gebel Egat and the
south faces of Gebel Heleikonti. It contains a well, =Bir Egat=,
situated east-south-east of the peak, about twenty-six kilometres
up from its junction with Alaqi, and there are extensive remains of
old mining operations to be seen in the same neighbourhood. Passing
east and south of Gebel Egat, the wadi emerges from the mountains,
coursing almost due west; and after receiving various feeders, the
principal of which is =Wadi Hiteib=, from the mountains to the north,
it enters Wadi Alaqi in longitude 34° 40′, about twenty kilometres
west of Gebel Egat.
=Wadi Hateib=,[88] which enters Wadi Alaqi about twenty kilometres
below Wadi Egat, has its heads in the south faces of Gebel Um el Tiur
el Foqani and the north flanks of Gebel el Hateib or Suhin. Coursing
generally south-westward, it receives small feeders on the west from
Gebels Adraq and Guqub. About four kilometres above where it enters
Wadi Alaqi, Wadi Hateib is joined from the east by =Wadi Suhin=,
the heads of which drain the south faces of Gebel Hateib or Suhin.
=Wadi Guqub=, a very small wadi which enters Alaqi six kilometres
lower down than Hateib, drains the hilly tract which here lies to
the north of Alaqi; it contains an important well, =Bir Guqub=,
which yields good water though in varying quantity. A road leads
from Wadi Alaqi up the Wadi Guqub past the well and on to Aswân,
_via_ El Haimur.
=Wadi Um Teneideb= drains the western faces of Gebels el Adraq
and Guqub, and joins Wadi Alaqi in longitude 34° 11′, about
thirty-three kilometres below Wadi Gugub. It has two main branches,
which unite about ten kilometres above the point of junction with
Wadi Alaqi. The old mines of Betam are situated near the northern
of the two branches, about seven kilometres west of Gebel el Adraq,
on the road just mentioned as leading from Wadi Alaqi to Aswân.
=Wadi Defeit=, which is probably the most important Egyptian tributary
of Wadi Alaqi, has its heads in Gebels Heleikontî and Heianai, about
the meridian of 35°. Its general course is that of a flat circular
arc convex to the north and having its chord east and west; the total
length of its main channel, from its head in Gebel Heleikontî to
its junction with Wadi Alaqi in longitude 34° 10′, is over one
hundred kilometres, while its numerous tributaries probably reach a
total length three times as great. The principal head of Wadi Defeit
is called =Wadi Sarid=; its branches extend among the hills close to
the heads of Wadi Egat and Wadi Miaus. The name Defeit is applied
to the wadi where Wadi Sarid is joined by the feeders from Gebel
Heleikontî. Passing between the high ranges of Heianai on the north,
and Heleikontî and Shanaiyet on the south, Wadi Defeit receives
numerous feeders, of which the principal are the =Wadis Dauriai=
and =Hamidâ=, both entering it from the mountain to the south;
continuing westwards, it cuts through the north end of the mass of
Gebel Um el Tiur el Foqani, and on emergence is joined by the =Wadi
Bint el Feqoh=, a great westward-coursing tributary draining the
north flanks of the Heianai range and the more northerly mountain
of Anweyib. Continuing its westward course, Wadi Defeit passes
between Gebels Um el Tiur el Tahtani and Adraq; then it enters on an
extensive tract of more open country, receiving three main feeders,
=Wadi Meladoyeb=, =Rod Hauanin=, and =Wadi Bagharid=, from the hills
to the north, before joining Wadi Alaqi.
=Wadi Seiga=, the next great northern tributary of Wadi Alaqi, has
only been partially explored. Its head is in the watershed range near
the conspicuous twin peaks of Gebel Sheyenit. Pursuing at first a
southerly course, it cuts through the east side of the mass of Gebel
Seiga; and about thirty kilometres lower down passes through hills
with old gold mines on either hand. Below the mines, Wadi Seiga takes
a south-westerly course, and receives a large tributary from either
side. That from the west, called =Wadi Deheis=, heads in Gebel Deheis
and curves round east of Gebel Abu Brush, receiving in its course
two great feeders, the =Wadis Um Gholqa= and =Abu Had=, both of which
head far to the north in the main watershed. The eastern tributary,
called =Wadi Um Derera=, drains the south part of the hill-mass in
which the Seiga mines are situated. Wadi Seiga joins Wadi Alaqi in
longitude 33° 53′, some forty-five kilometres below the mines;
the junction is outside the limits of the maps in this volume.
* * * * *
[Footnote 84: Dry in 1906.]
[Footnote 85: To be distinguished from another mountain of the same
name further south, near the Wadi Hodein.]
[Footnote 86: To be distinguished from the better known Wadi Egat
much further south, a feeder of Wadi Alaqi.]
[Footnote 87: “L’Etbaye.” p. 1.]
[Footnote 88: Mr. Campbell’s map names this Wadi Hadaiber. My
guides, however, gave the name Gebel Hateib to the mountain which
is drained by the wadi, and I have ventured to alter the name on
this ground. Mr. Campbell’s map names the mountain Gebel Suhin;
it probably has two names, as is quite usual in desert nomenclature,
because its two sides are drained by different wadis. There is a Wadi
Hiteib draining from the south-eastern part of the same hill-mass
into Wadi Egat.]
CHAPTER V.
* * * * *
=THE WADIS DRAINING EASTWARDS TO THE SEA.=
* * * * *
The eastward drainage differs strikingly from the westward in being
much steeper and more complex, due to the greater proximity of
the mountains to the sea than to the Nile. While all the westward
drainages form parts of but three great basins, there are on the
seaward side no less than forty-seven distinct drainage basins,
each having a separate outlet to sea (_see_ Plate II). Only two of
the eastern basins, Hodein and Di-it, are comparable in size with
the great basins of the west, the remainder being relatively small.
The following list gives the names in order, from north to south, of
the main wadis draining to the sea, with their tributaries so far as
they fall within the area treated of in this volume, the principal
feeders of the tributaries being indicated in parentheses. It may
be remarked that the minor feeders and tributaries are frequently
of greater importance to the Arabs than the main channels, owing to
their containing vegetation in greater abundance.
WADI DABUR.
WADI IGLI.
WADI UM KHARIGA.
WADI SUKARI.
WADI UM TUNDEBA.
WADI AMBA-UT.
{ Wadi Ghuel.
{
{ Wadi Fegas.
{
{ Wadi Ma-ud.
{
WADI GHADIR { Wadi Sabahia.
{
{ Wadi Zabara (Wadi Atabi, Wadi Um Abid, Wadi Um
{ Dafiri).
{
{ Wadi Allawi (Wadi Lewewi).
WADI UM GAMIL.
{ Wadi Huluz (Wadi Abiad lil Huluz, Wadi Mahali,
{ Wadi Tarfawi, Wadi Hilgit lil Huluz, Wadi Um
{ Semiuki, Wadi Um Hegiligi lil Huluz, Wadi
{ Marasan, Wadi Um Suerab lil Huluz, Wadi Abu
{ Gerifat, Wadi Um Iteili, Wadi Ga-etri, Wadi Abu
{ Etl).
{
{ Wadi Um Suerab lil Gemal.
{
{ Wadi Durunkat.
{
{ Wadi Hafafit (Wadi Abu Had, Wadi Hefeifit).
WADI GEMAL {
{ Wadi Nugrus (Wadai el Nom, Wadi Abu Rusheid,
{ Wadi Abu Sada, Wadi Sikait).
{
{ Wadi Mukhatatat.
{
{ Wadi Um Sueh.
{
{ Wadi Um Heran.
{
{ Wadi Nasbia.
{
{ Wadi Abiad (Wadi Um Seyal).
{
{ Wadi Um Kabu.
WADI UM EL ABBAS Wadai el Anz.
WADI ABU GHUSUN Wadi Romit (Wadi Shoab, Wadi Abu Hegilig, Wadi
Hefeiri).
WADI EL RANGA.
WADI HAMATA.
WADI HARATREIT.
WADI KHASHIR.
WADI MIKBI.
{ Wadi Um Karaba.
{
{ Wadi Eidab.
{
{ Wadi Um Gunud.
{
{ Wadi Um Rishan.
{
{ Wadi Um Homar.
WADI LAHAMI {
{ Wadi Sefent.
{
{ Wadi Um Khuzama.
{
{ Wadi Um Ghobasha.
{
{ Wadi Gumudlum.
{
{ Wadi Abu Marwa lil Lahami.
{ Wadi Naait (Wadi Um Sumur, Wadi Abu Marwa lil
WADI MUKHIT { Naait, Wadi Abu Ghalqa).
{
{ Wadi Abu Daba (Wadi Murra).
WADI ABU DIBBAN.
WADI MINDEIT Wadi Um Sellim lil Mindeit.
{ Wadi Um Maiat.
{
WADI KALALAT { Wadi Dibag lil Batoga.
{
{ Wadi Um Sellim.
WADI UM GORAN.
WADI KUNSEROB Wadi Dibag lil Kunserob.
WADI ABU BERIGA.
{ Wadi Abu Debebi lil Khoda.
{
{ Wadi Salib el Abiad.
{
{ Wadi Salib el Azraq (Wadi Um Karaba).
{
{ Wadi Allawi.
{
{ Wadi Um Tawil lil Khoda.
{
{ Wadi Hindia.
{
{ Wadi Um Akra.
{
WADI KHODA { Wadi Shut (Wadi Abu Hugban, Wadi Tawil lil
{ Shut).
{
{ Wadi Um Gubur.
{
{ Wadi Shib.
{
{ Wadi Um Seyal lil Khoda.
{
{ Wadi Gumudlum.
{
{ Wadi Bulluk.
{
{ Wadi Um Lassaf.
{
{ Wadi Shenshef.
WADI UM ETLI.
WADI SORUBIAB Wadi Bint el Kurdum.
{ Wadi Titai.
{
{ Wadi Abu Nikheil.
{
{ Wadi Abu Reye.
{
{ Wadi Um Buerat.
{
WADI RAHABA { Wadi Abiad (Rod Elbel, Wadi Abu Ribian).
{
{ Wadi Megah.
{
{ Wadi Hutit.
{
{ Wadi Dagalai lil Rahaba.
{
{ Wadi Abu Had.
{
{ Wadi Marafai.
{ Wadi Arned (Wadi Muegil, Wadi Um Arta).
{
{ Wadi Saalek.
{
{ Wadi Um Reit (Wadi Dreb, Wadi Malhat).
{
{ Talet Um Danaqa.
{
{ Talet Um Sideiri.
{
{ Wadi Gihab (Wadi Gihab Abu Derb).
{
{ Wadi Maghal.
{
{ Wadi Naam (Wadi Fil, Wadi Abu Seyal, Wadi Um
{ Bisilla, Wadi Erf Um Araka, Wadi Arais, Wadi
{ Silsila, Wadi Abraq, Wadi Betan).
{
{ Wadi Dif (Wadi Feqoh, Talet Um Karaba, Wadi
{ Enqireidia, Wadi Gelabat Shabai).
{
{ Wadi Orga el Atshani.
WADI HODEIN {
{ Wadi Orga el Rayani.
{
{ Wadi Anfeib (Wadi Anfeib el Tawayib, Wadi
{ Atalab, Wadi Mitatib).
{
{ Wadi Khasiya.
{
{ Wadi Madi (Wadi Difotib, Wadi Eirahimib, Wadi
{ Faditiai, Wadi Shellal el Gharbi, Wadi Sinatib,
{ Wadi Tugudbaia, Wadi Berendiyeb, Wadi Atluk,
{ Rod Mukrayib, Wadi Kolaiqo, Wadi Edunqul).
{
{ Wadi Um Tenedba.
{
{ Wadi Khashab (Wadi Dehaiartib).
{
{ Wadi Um Seleim.
{
{ Wadi Kreiga (Wadi Korbiai, Wadi Meneiga, Wadi
{ Abiad, Wadi Eberer, Wadi Shigig).
WADI KOLAIQO.
{ Wadi Radad.
{
{ Wadi Shellal el Sharqi.
{
{ Wadi Muqur (Wadi Ti Ilak, Wadi Tikosha).
{
{ Wadi Qadiloi (Talet Tihu Shana).
{
WADI SHAB { Wadi Baaneit.
{
{ Wadi Kilanai.
{
{ Wadi Diqdib.
{
{ Wadi Um Saha.
{
{ Wadi Sherefa el Sharqi.
{
{ Kwat Hewah.
{ Wadi Mantil Hasium.
{
{ Wadi Hilwit Hasium.
{
{ Wadi Shinai.
{
{ Wadi Delawet.
{
{ Wadi Abu Hodeid.
{
{ Rod Anut Berer.
{
{ Wadi Tikraneib.
{
WADI IBIB (HASIUM) { Wadi Abu Hireiq.
{
{ Wadi Odruk.
{
{ Wadi Nilateib.
{
{ Wadi Medarai (Wadi Merdiyeb, Wadi Um Rasein).
{
{ Wadi Soaorib (Wadi Haiyo, Wadi Hankuk, Wadi
{ Dishlo, Wadi Eimya, Wadi Qidmib).
{
{ Wadi Um Bishtit (Wadi Delawet, Wadi Orgem).
{
{ Wadi Habliai.
{ Wadi Sarobaiya.
{
{ Wadi Awitla.
{
{ Wadi Lasewid.
{
WADI MEISAH { Sarob Kwan.
{
{ Akla Da-aiyob.
{
{ Hanqun Ra-ub.
{
{ Wadi Eqaiyib.
{ Wadi Shendib.
{
{ Wadi Hareitra.
{
{ Wadi Qurat (Wadi Dibir, Wadi Hashimaiyib, Wadi
{ Oshqeq, Wadi Mashushenai).
{
{ O Harbub.
{
WADI KIRAF (DI-IB) { Wadi Salalob.
{
{ Wadi Warabeit (Sarob Kwan, Wadi Wi-eqwer, Wadi
{ Kwileimidaiyeib).
{
{ Wadi Qumad Lim.
{
{ Wad el Qireira (Wadi Didaut, Wadi Baueiwai).
{
{ Wadi Halal Hendiyeb.
WADI DI-IT.
WADI EIKWAN.
{ Wadi O Sir Hadal.
{
{ Wadi Qeirat.
WADI YOIDER {
{ Wadi Siamtit.
{
{ Wadi Akwamtra.
WADI AIDEIB Wadi Yahameib (Wadi Akau, Wadi Kansisrob).
WADI TODHI.
WADI DELOWA.
{ Wadi Um Seyal.
WADI SERIMTAI {
{ Wadi O Sir Eirab.
WADI SHELLAL.
WADI AQILHOQ.
WADI AQWEI.
WADI
KREIT-REIT-OR.
WADI QABATIT.
=Wadi Dabur= falls only partly within the district to be described
in the present volume. It drains the hill country between Gebels
Atut and Igli, by numerous feeders, and courses north-east to enter
the sea about latitude 25° 16′, beyond the limits shown on the map.
=Wadi Igli= is a short wadi draining from Gebel Igli and coursing a
little north of east to the sea somewhat south of latitude 25° 10′.
=Wadi Um Khariga= has its principal head in a _cul-de-sac_ west
of Gebel Ghuel and north of Gebel Hangalia, at an altitude of
approximately 800 metres above sea-level. Near its head there is an
easy pass entering from the west, forming a line of communication
with Hangalia mine; the highest point of the pass is 773 metres above
sea-level. After coursing for about twelve kilometres a little west
of north between the high hills called Gebel Um Khariga, with a rapid
fall, the wadi turns north-east, receiving just below the bend a large
tributary which heads in an easy pass to Wadi Ghadir. Near this place
a road crosses the wadi northwards through the low hills, and passes
west of Gebel Igli el Iswid; it is said to go on to Qena. Further
on in its course towards the sea, Wadi Um Khariga receives another
tributary draining the south flanks of Gebel Igli el Iswid. The
lower portion of Wadi Um Khariga has not been surveyed in detail;
but it passes through a tract of lower hills and enters the sea in
about latitude 25° 5′. The total length of the main channel of
Wadi Um Khariga is about fifty kilometres, and the area of its basin
is about 300 square kilometres.
=Wadi Sukari=, the next wadi to the south, heads at a pass from Wadi
Ghadir; for about nine kilometres it courses east of north between
the eastern range of Gebel Um Khariga and the craggy Gebel Sukari,
then turns more to the east and enters the sea a little south of Wadi
Um Khariga. Near the south end of Gebel Sukari there are numerous
ruins and some ancient gold mines.
=Wadi Um Tundeba= heads near the mountain of the same name, and
courses about north-east to the sea. In one of the heads of this wadi,
about three kilometres west of the summit of Gebel Um Tundeba, is
an important water source, called =Galt Um Tundeba=. This is a rock
basin situated about one kilometre up a little wadi; it contained
a good supply of water in December 1905, but as it depends for its
supply on rainfall in the surrounding hills, it cannot be relied on
as a permanent water source.
=Wadi Amba-ut= is a small wadi originating near the granite hills
called Gebel Amba-ut, and following a course about parallel with
the Wadi Um Tundeba seawards.
=Wadi Ghadir=, which drains by numerous tributaries the eastern
face of Gebels Hangalia and Zabara, as well as the hilly country
round Gebels Ghadir, Allawi, and Lewewi, has a basin of over 500
square kilometres and a length along its main channel, not counting
its feeders, of about forty-five kilometres; it enters the sea in
latitude 24° 50′.
The principal head of Wadi Ghadir is at an easy pass between Gebels
Ghuel and Um Khariga, in latitude 24° 55′, at an altitude of about
500 metres above sea-level. Coursing south-east, it receives important
feeders from gorges in the west face of Gebel Ghuel; the principal
of these feeders, =Wadi Ghuel=, contains water holes, which gave an
excellent supply of rain water in 1905-06. A little further along its
course, Wadi Ghadir passes the low hill district called =Kurdeman=,
where there are some old gold mines, and then receives as tributaries
=Wadi Fegas= and =Wadi Ma-ud=, draining the mountains of Ghuel and
Hangalia. Taking now a more easterly direction towards Gebel Ghadir,
it receives from the north-west =Wadi Sabahia=, draining the craggy
felsite hill of the same name; there are some old gold mines about
a kilometre north-east of this hill, in a branch of Wadi Sabahia.
The =Wadi Zabara=, an important tributary draining the north flanks
of Gebel Zabara and the south-east part of Gebel Hangalia, enters
Ghadir from the south-west, nearly opposite Wadi Sabahia. Wadi
Zabara has itself three main heads, called by the separate names of
=Wadi Atabi=, =Wadi Um Abid=, and =Wadi Um Dafiri=. There are ruins
and ancient mines close to where the Wadi Atabi joins Wadi Zabara,
while in the upper part of Wadi Um Dafiri are more extensive ruins
and numerous ancient emerald mines, as well as a series of rock
basins which were yielding good water in 1905-1906.
After receiving the Wadi Zabara, Wadi Ghadir continues its course
south-east past Gebel Ghadir, from the slopes of which numerous small
feeders enter the main channel. Almost due south of Gebel Ghadir,
in the southern one of two branches into which the wadi splits as
it passes round a low island-like mass of hills, is =Bir Ghadir=,
a well sunk in the alluvium of the wadi floor. When I visited it
early in 1906 this well was filled by downwash, and the Arabs of the
district deferred digging it out until the rock basins were empty; it
is an important water source and is said to yield good supplies. The
mines of Hangalia were supplied by water from Bir Ghadir in 1905,
when nearer sources were dry.
About six kilometres below the well, Wadi Ghadir passes close north
of Gebel Allawi, where there are some old gold mines. The =Wadi
Allawi=, which with its tributary =Wadi Lewewi= drains the hilly
country between Gebels Zabara and Sikait, enters Ghadir a little to
the east of Gebel Allawi; both Allawi and Lewewi are very tortuous
wadis, their names in fact meaning “crooked” in the Ababda tongue
(Lewewi is a diminutive of Allawi).
=Wadi Um Gamil=, the next wadi entering the sea to the south, drains
the hilly country south-east of Sikait. Very little is known about its
course, the only part surveyed being the heads east of Gebel Sikait.
=Wadi Gemal= is the terminal portion, about sixty kilometres in
length, of the main drainage channel from a basin nearly 200 square
kilometres in area. With its numerous large feeders, the principal
of which is Wadi Huluz, about eighty kilometres in length, the Wadi
Gemal drains the Hafafit and Nugrus ranges of mountains on the north,
and a great mass of high mountains, including Gebel Hamata, on the
south. It will be convenient here to describe only the Wadi Gemal
proper, leaving the great wadis which join to form it, and its major
tributaries, for separate treatment.
The name Wadi Gemal is first given to the drainage at the point
where Wadi Huluz turns sharply eastward in longitude 34° 39′.[89]
At this point the country becomes more open than in the gorge-like
Wadi Huluz. To the north is a mass of low granite hills, some of
which have remarkable shapes, with a great deal of drift sand,
while to the south are the higher dark hills flanking Gebel Um
Suerab. Among these surroundings the wadi pursues a winding course,
with a general north-easterly direction, receiving the Wadi Um Suerab
lil Gemal and the Wadi Durunkat as tributaries from the south.
About six kilometres below the point of influx of Wadi Durunkat, on
the right (south) side of Wadi Gemal, is a locality called =Geli=,
where there are extensive ruins. A very remarkable rock in the middle
of the main wadi marks the place whence a track leads south-east
past the ruins and across the heads of Wadis Um Ghazal and Mukhatatat
into the upper part of Wadi el Abiad.
Passing a remarkable bell-shaped hill (Gebel Um Regeba, rising to
571 metres above sea, the “mosque rock” of Floyer’s map) about
four kilometres on the left, Wadi Gemal receives two small feeders
coming from among the hills to the south, and then the important
tributary called Wadi Hafafit enters from the north-west.
Below the point of influx of Hafafit, the Wadi Gemal becomes more
narrow, and shut in by high hills. Near the meridian of 34° 49′
there are some ruins on the north side of the wadi, and a little
further on the Wadi Nugrus, one of the largest tributaries of Wadi
Gemal, enters from the north-west at a rather sharp bend. Further
down, Wadi Gemal receives =Wadi el Mukhatatat= and =Wadi Um Sueh=
from the south, and =Wadi Um Heran= and =Wadi el Nasbia= from the
north. The Wadi Abiad, which next joins Wadi Gemal from the south,
is an important feeder. Two kilometres below the mouth of Wadi el
Abiad, the =Wadi Um Kabu= enters Wadi Gemal from the north-west,
while nearly opposite to it is a small wadi, called =Um Sellimi=,
in which there are water pools after rain. The wadi now curves more
northward round the base of the double-topped hill mass called Madaret
Um Gamil. Just beyond the northward turn a road[90] leads up a narrow
tortuous gully in a north-westerly direction, passing close south
of the hill summit and forming the most ready means of ascent of
Madaret Um Gamil; the climb from the road at the top of the gully is
only about 200 metres. The course of the Wadi Gemal to the sea has not
been surveyed beyond four kilometres east of Madaret Um Gamil; it goes
through low hilly country and enters the sea in about latitude 24°.
The fall of the Wadi Gemal averages about six metres per kilometre,
being as low as four metres per kilometre in some places, and probably
exceeding ten metres per kilometre where it emerges from the hills on
to the coast-plain. It is interesting to note that the observations
of level indicate a local increase of gradient above the place of
influx of Hafafit and Nugrus. The Wadi Gemal is well supplied with
trees, as are also almost all its tributaries with the exception of
the sandy Wadi Hafafit.
=Wadi Huluz= is a long winding wadi, mostly shut in by high rock
walls, draining the high mountains round Gebel Hamata and coursing
north-east for a distance of over seventy-five kilometres to the
point, near Gebel Um Suerab, where, turning sharply eastward,
it enters more open country and takes the name of Wadi Gemal. The
slope of Wadi Huluz averages fifty metres per kilometre for the
first ten kilometres from its heads in the mountains. In the next
ten kilometres the slope is much flatter, being twenty metres per
kilometre. From twenty to forty kilometres from its head the average
fall is only ten metres per kilometre, while still further down the
rate of fall lessens till in the last reaches, just before entering
the Wadi Gemal, it is only six and a half metres per kilometre.
The principal heads of Wadi Huluz are close to the south-east
of Gebel Hamata, in a _cul-de-sac_ formed by the high mountains
of Gebel Hamata (1,978 metres above sea) and Gebel Ras el Kharit
(1,661 metres). Here a number of steep gorges unite to form the main
channel, which due south of Hamata has an altitude of 1,053 metres
above sea-level. Following a winding course among the mountains as
a rapidly falling valley with a sandy floor averaging 100 metres or
more in width, it passes west of the great mass of Hamata, receiving
the drainages from the north-east flanks of that mountain and from
the north face of Gebel Um Hasidok. At its crossing the meridian of
35° it receives as a feeder the =Wadi el Abiad lil Huluz=, which
drains the north face of Hamata and the south flanks of Gebel Abu
Ghusun; draining mostly from granite country, this feeder has a
floor of coarse granitic sand, from the whitish colour of which it
takes its name.
The next feeder of Wadi Huluz, called =Wadi Mahali=, enters from
the south, its head being on the main watershed between Gebels Um
Usher and Um Hasidok. Passing between Gebels Um Usher and Um Laham,
the Wadi Huluz receives =Wadi Tarfawi=, draining the mountain of the
same name from the east. Further down, feeders come in from Gebel
el Mehali on the south and from the high hills south of Gebel Um
Heshenib on the north. Near the meridian of 34° 50′ two important
tributaries enter Huluz near together from the south. The upper one,
=Wadi Hilgit lil Huluz=, heads in a very steep and difficult pass,
leading into Wadi Hilgit lil Kharit. The lower one, called =Wadi Um
Semiuki=, drains the north-east flanks of Gebel Abu Hamamid. Nearly
opposite the mouth of Wadi Um Semiuki is another feeder of Wadi Huluz,
which I believe forms the main drainage channel for the south face
of Gebel Um Heshenib; but it is said to be very steep and stony,
and my Arabs preferred to reach Gebel Um Heshenib by a small wadi,
containing several tombs, some four kilometres higher up Wadi Huluz,
whence there is a stony pass leading into the above-mentioned main
drainage channel at a point above the obstructions in it.
About eight kilometres further on, on the north-east side of the wadi,
there is a low gap over which by a very easy pass one can descend
into the head of Wadi Durunkat, leading to Wadi Gemal. Some three
kilometres lower down, Huluz receives two tributaries together;
one, from the south-east, is called =Wadi Um Hegiligi lil Huluz=,
while the other, from the south-west, is called =Wadi Marasan=
and heads in an easy pass on the main watershed, over which a track
leads south-east and south to the well and tomb of Sheikh Shadli.
Two sheikhs’ tombs and some smaller graves exist at a bend in
the Wadi Huluz, three kilometres below the point of influx of Wadi
Marasan. Below these enter as feeders =Wadi Um Suerab lil Huluz=
from the north, and =Wadi Abu Gerifat= from the south. The wadi
now becomes very tortuous. Near the meridian of 34° 40′, on the
south side of the wadi, at a bend where trees are very abundant,
is a small gully containing the important water holes called =Um
Gerifat=. These are rock basins fed by rain water draining down
steep gorges from the hills round the twin-peaked Gebel Um Sedri;
they are easily accessible in a few minutes from the main wadi, and
contained good supplies of water in the winter of 1905-1906. About
four kilometres lower down, the =Wadi Um Iteili= enters from the
east, and about five kilometres beyond this Huluz opens out into a
somewhat triangular space, when the =Wadi Gaetri= enters from the
west and =Wadi el Khisei= from the east. The Wadi Gaetri leads by
an important pass into the more open country to the west (wells of
Wadi Khashab and Wadi Natash).
At the open space above-mentioned, Wadi Huluz turns northward, winding
somewhat, for some eight kilometres, and then, after receiving the
=Wadi Abu Etl= as a feeder from the west, turns sharply eastward
and becomes the Wadi Gemal.
=Wadi Durunkat=, a tributary of Wadi Gemal, forms an important road
from Wadi Gemal into the higher parts of Huluz. By following it up to
its head about twenty kilometres from its junction with Wadi Gemal,
one can enter Wadi Huluz by a very easy pass in longitude 34° 46′,
thus cutting off the long winding course of Wadi Huluz itself; and
from this pass one can cross the main watershed by the Wadi Marasan
to reach Bir Shadli.
=Wadi Hafafit=, another tributary of Wadi Gemal, has its head situated
close to the east side of Gebel Migif, in latitude 24° 50′, on
the main watershed, where there is an easy pass into the head of Wadi
Shait. Following a very straight course for nearly forty kilometres
south-east, with the remarkable range of high gneiss mountains called
Gebel Hafafit on the left, and the sugar loaf granite hills of Abu
Had on the right, Wadi Hafafit forms a broad barren valley in which
there are heavy accumulations of blown sand. =Wadi Abu Had=, a small
western feeder of Hafafit, is well known by reason of the well of
bitter water, =Bir Abu Had=, at its head. An eastern feeder of Wadi
Hafafit, which joins it shortly before the junction with Wadi Gemal,
is called by the diminutive name of =Wadi Hefeifit=.
=Wadi el Abiad=, likewise a tributary of Wadi Gemal, derives its name
from the coarse white granitic sand which forms its floor. Its heads
are situated near latitude 24° 20′, among the granite mountains
called Gebel el Abiad and on the northerly slopes of Gebel Um
Heshenib. There is a very steep pass from its head, east of Gebel
Um Heshenib, into Wadi Huluz. Pursuing an almost northerly course
and falling rather rapidly, Wadi el Abiad is at first very wide,
with high granite hills on each side. It narrows further down, at
a point opposite Gebel Shoab, where a small eastern feeder leads by
an easy sandy pass into the Wadi Shoab. A little lower down, passing
into diorite country, it turns more to the east, and after receiving
the =Wadis Um Seyal el Foqani= and =el Tahtani= from the south-east,
enters the Wadi Gemal near Madaret Um Gamil. The wadis called Um
Seyal receive their name from the abundance of acacia trees in them;
at the head of Wadi Um Seyal el Foqani there is a pass leading by
the Wadai el Anz into Wadi Um el Abbas.
=Wadi Nugrus=, an important tributary of Wadi Gemal, commences
its course on the main watershed west of Gebel Nugrus, in latitude
24° 48′, at the pass into Wadi Gerf, 690 metres above sea-level,
and courses south-east in almost a straight line for nearly forty
kilometres to join the Wadi Gemal in latitude 24° 34′ and longitude
34° 50′. The fall to this point is some 450 metres, or an average
of over ten metres per kilometre, but the fall is most rapid near
the head, where the floor of the wadi is rocky and steep; the slope
for the first few kilometres is over double the average.
The approach to the head of Wadi Nugrus from the north, by one
of the heads of Wadi Gerf, is almost a plain. But as soon as
Wadi Nugrus is entered one becomes very sensible of the greater
steepness of the eastern drainage by the stony nature of the track
and the rapid fall. The wadi here is in fact only a narrow gorge
with the huge mountains of Hafafit and Nugrus on the west and east
sides respectively. Some three kilometres below the pass, close to
the west side of the wadi, in a narrow gorge, is the spring called
=Megal el Harami=, situated in gneiss rocks, and giving supplies of
good water; the water infiltrates slowly, however, so that the yield
is not sufficiently rapid to supply large quantities at once. Lower
down, the wadi broadens out considerably, with a sandy floor in the
middle of which low dark hills rise like islands. About thirteen
kilometres below the head, an important feeder, the =Wadai el Nom=,
comes in from the north-east. This wadi drains the south-east flanks
of Gebel Nugrus and the west flanks of Gebel Hangalia; it contains
rock basins holding water for some time after rain, and leads to
a steep winding pass which enables one to make a circuit round
the great granite mountain of Gebel Nugrus. The pass is, however,
impracticable for baggage camels, and one has to dismount from a
riding camel in order to get over.
Beyond the junction of Wadai el Nom, the Wadi Nugrus continues its
straight course south-east, between the long range of Gebel Hafafit
on the west and Gebel Zabara on the east. Some thirty kilometres
below its head, Wadi Nugrus receives the =Wadi Abu Rusheid= from
the north, and a little further on one encounters on the east the
ruins of an old village called =Medina Nugrus=. Just opposite the
ruins is a small feeder called =Wadi Abu Sada=, a short distance up
which are rock basins yielding water after rain, but these were dry
in 1905. Not far below this, there are some old workings in a small
feeder on the east side of the Wadi Nugrus, six kilometres above
its junction with Wadi Gemal.
=Wadi Sikait=, a tributary of Wadi Nugrus, heads in some high red
granite hills north-west of Gebel Sikait. A pass leads over the
western head, while in the eastern one is a small spring, which,
though a mere trickle, is said to be constant and to yield excellent
water. These two heads join at a well recently sunk by miners. Lower
down, on the flanks of Gebel Sikait, are numerous emerald mines,
with an ancient tower and many other ruins, and in the wadi near
these is another recently sunk well, which has only yielded water
of inferior quality. From near the mines there lead two tracks on
either side of the wadi. That to the west is a rough path over gneiss
hills into Wadi Abu Rusheid. That to the east winds past the ancient
tower, ascending gradually to a pass into one of the heads of Wadi
Um Gamil. Lower down the Wadi Sikait are many ancient mines, and the
ruins of three rock temples and an ancient village. Just before the
Wadi Sikait enters Wadi Nugrus, a track leaves on the east for =Wadi
Um Heran=, in which I am told water is sometimes to be found. The
length of the Wadi Sikait is about fourteen kilometres, and its fall
is from 535 metres above sea at the pass at its head to about 250
metres where it enters Wadi Nugrus, or an average slope of twenty
metres per kilometre. It is a narrow gorge shut in by high hills,
with a fair abundance of trees.
=Wadi Um el Abbas= originates by the union of several heads in
the neighbourhood of the high granite hills of Um el Abbas and Abu
Hegilig. One of its heads leads to an easy pass called =Kab el Haram=,
four and a half kilometres east of Gebel Abu Hegilig. Another, close
east of Gebel Abu Hegilig, leads to another easy pass into the head of
a tributary of Wadi Romit. A third head, called the =Wadai el Anz=,
leads to yet another pass into Wadi Um Seyal el Foqani, a tributary
of Wadi el Abiad. The course of the Wadi Um el Abbas has only been
surveyed for a short distance below the place where its heads unite;
it pursues a north-easterly course among low hilly country and enters
the sea in about latitude 24° 36′.
PLATE VI.
[Illustration: MAP OF THE DISTRICT OF NUGRUS & SIKAIT
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
=Wadi Abu Ghusun= commences its course among the high mountains of
Gebel Abu Ghusun, north of Gebel Hamata. Pursuing a northerly course
for about ten kilometres, it passes close east of the sharp granite
peak of Gebel Hefeiri, then turns more to the east, receiving Wadi
Romit as an important tributary from the west near the bend, and
reaches the sea in about latitude 24° 29′.
=Wadi Romit=, a tributary of Abu Ghusun, originates in the granite
mountains called Gebel el Abiad, near the parallel of 24° 20′ and
follows a winding course in a general easterly direction for about
sixteen kilometres to its junction with Wadi Abu Ghusun. It receives
several important tributaries. The chief of these, =Wadi Shoab=,
originates close to the south-west of Gebel Shoab, where there is
an easy pass into the Wadi el Abiad. Another tributary of Romit,
the =Wadi Abu Hegilig=, drains the south part of Gebel Um el Abbas,
while a third is the =Wadi Hefeiri=, draining the hills round the
granite peak of the same name. All these tributaries, like Wadi
Romit and Wadi Abu Ghusun itself, contain abundance of trees, and
have a rather rapid fall.
=Wadi Hamata= drains the eastern flanks of the high hills north
of Gebel Hamata, its principal heads being about latitude 24°
15′. Only the heads of this wadi have been surveyed; it follows a
winding course among the lower hill country and reaches the sea in
about latitude 24° 24′.
Of the three wadis draining seawards south of Hamata, called =Wadi
Haratreit=, =Wadi Khashir=, and =Wadi Mikbi=, very little is known,
not even their heads having been visible from the stations which
I occupied. The summits of the mountains drained by them have,
however, been mapped, and their courses are approximately known from
the accounts of Floyer; these are indicated on the map probably in
nearly their true positions. Draining mostly steep and precipitous
mountain faces, the upper parts of these wadis must have an extremely
rapid fall, and consequently a rough stony floor.
=Wadi Lahami=, which enters the sea north of the peninsula of Ras
Benas, is well known by reason of the easy pass over the main
watershed at its head forming an important means of access to
Berenice from the west. At this point, four kilometres north-east
of the white quartz cone called Marwot Elemikan, the watershed is
sandy, level, and low, being only 590 metres above the sea. The
drop on crossing the watershed is fairly rapid, the wadi winding
about among the hills in a general north-easterly direction. About
six kilometres below its head, Lahami receives the =Wadi Um Karaba=,
which drains the south face of Gebel Abu Gurdi. A little further on,
=Wadi Eidab= enters from the south-east; this feeder is said to head
in a rough steep pass over the hills into the Wadi Abu Daba. After
passing between the high hills of Gebels Um Goradi and Um Gunud, Wadi
Lahami receives the short =Wadi Um Gunud=, in which there are two
well known galts, or rock basins forming reservoirs of rain water;
these contained good supplies in 1906-7. Lower down, Wadi Lahami
crosses a stony sloping plain, where it receives the drainage from
the north and east flanks of Gebel Abu Gurdi and from the mountains
to the north of it, by a series of feeders, the principal of which
are =Wadi Um Rishan=, =Wadi Um Homar=, and =Wadi Sefent=. East of
the plain there is a sort of shunt or loop-line of Wadi Lahami,
called the =Wadi Abreik=, which is preferred to the main channel
for a road. Just receiving Wadi Sefent, Wadi Lahami turns sharply
eastward, and then north-eastward, receiving as feeders =Wadis Um
Khuzama=, =Um Ghobasha=, and =Gumudlum=, draining Gebels Um Sellim
and Gumudlum to the north; these feeders are said to contain natural
reservoirs full of water after rain. From the south, Lahami is fed by
the =Wadis Um Eshub= and =Abu Marwa lil Lahami=, draining the lower
hill country. The lower course of Wadi Lahami has not been traced in
detail. It passes north-west of the well marked granite peak called
Gebel Um Huk, as remarked above, and reaches the sea north of the
peninsula of Ras Benas. To get to Berenice, one leaves Wadi Lahami
about twenty-four kilometres below the pass at its head, and turns
off south-east up the tributary Wadi Abu Marwa, which leads to Wadi
Naait by an easy road.
Wadi Lahami is well supplied with trees; it presented a very green
appearance early in 1906, but the absence of rain for a year made
it much more desolate looking in 1907, all the foliage being then
blackened and withered. Its length is approximately fifty kilometres,
its average slope twelve metres per kilometre, and the area of its
basin is about 650 square kilometres.
The drainage from the low hills on the =Peninsula of Ras Benas=,
except for a small portion which joins Wadi Mukhit, reaches the sea
by a multitude of small wadis, none of which bear special names. The
hills being nearer to the south side of the peninsula than to the
north, the wadis draining southwards are on the whole much shorter
and steeper than those draining northwards, and the latter cross a
sloping plain two or three kilometres wide to reach the sea. Passage
across the hills from south to north is only possible to camels at
a few places. The southern wadis are mostly barren, but the northern
ones contain abundance of a dark coloured grass of which camels are
fond. There is no permanent water source on the peninsula, the nearest
reliable source of supply being a galt in Wadi Mindeit, on the main
land, about twelve kilometres west of Berenice. The tip of the low
sandy projection of Ras Benas is marked by a sheikh’s tomb, one
of the largest on the coast. It is chiefly built of wreckage cast
up on the beach. From the hills it looks like a rectangular rock,
and I determined its position by triangulation as latitude 23°
53′ 50″ N., longitude 35° 47′ 13″ E. The sheikh’s memory
appears to be greatly venerated by sailors, and several of my camel
men made pilgrimages to the tomb to pray.
The =Island of Mukawar=, about six kilometres south of the sandy tip
of the ras, is nearly two kilometres in length from north to south. I
did not visit it, but it has the appearance of being made of coral;
its highest point, near the south end, is thirty-four metres above
the sea-level.
=Wadi Abu Daba= drains the eastern flanks of Gebel Eidab and Gebel
Um Maiat, and courses eastward through the lower hill country to
the coast plain, where it joins the drainage from Naait in Wadi
Mukhit. The principal feeder of Abu Daba is =Wadi Murra= which enters
it from the south-west a few kilometres before its emergence on to
the plain. At the head of Wadi Abu Daba there is said to be a rough
steep pass over the mountains into Wadi Eidab. The place where Abu
Daba debouches on to the coast plain is marked by a group of low
bouldery looking granite hills called Khasheib Abu Daba.
=Wadi Abu Dibban= is a short wadi draining eastwards from the hills
across the coast plain to the sea a little north of Berenice. In its
course across the plain it passes a little north of a conspicuous
granite hill called Sikeit, a well known landmark five kilometres
north-west of Berenice.
=Wadi Mindeit= drains the hills between Gebel Um Maiat and Gebel
Kalalat, entering the sea at Berenice.[91] =Wadi Um Sellim lil
Mindeit=, a shorter wadi coursing across the plain a little further
south, is interesting as furnishing the nearest fresh water source
to Berenice; it leads to a rock basin or galt among the hills, where
rain water collects. This source is some ten or twelve kilometres
from Berenice.
=Wadi Naait=[92] is a narrow tortuous gorge, with a sandy floor
shut in by high hills, coursing eastward to the coast plain a
little south of the 24th parallel. Though only a small wadi some
sixteen kilometres in length, it is well known because it forms
the usual road from Wadi Lahami to Berenice. Its actual head has
not been surveyed, but lies probably between the mountains of Um
Gunud and Um Hegilig. Its principal feeders are =Wadis Um Sumer=
and =Abu Marwa lil Naait=, which enter it from the north-west, and
=Wadi Abu Ghalqa=, entering from the north and draining the granite
hills called Gebel Abu Ghalqa. All three of these feeders enter Naait
near together, some ten kilometres before it emerges on the plain;
the lower part of the wadi is free from lateral branches. The fall
is ten metres per kilometre among the hills. On emerging from the
hills on to the sandy coast plain, it joins an ill-defined drainage
line called =Wadi el Mukhit=, which enters the sea at Port Berenice,
some fifteen kilometres further east. The name Wadi el Mukhit is also
given to other ill-marked drainage lines entering Port Berenice from
the sandy tract between the hills of the main land and the hills
of the peninsula of Ras Benas. Some three kilometres north-east
of the mouth of Wadi Naait, on the coast plain, is a conspicuous
isolated low hill, forming a well-known landmark and called =Grain el
Rih=. The plain drained by Wadi el Mukhit is a dreary sandy waste,
and the crossing of it in a high wind is very trying by reason of
the immense clouds of sand raised and carried in the air.
=Wadi Kalalat= heads in the north-west portion of Gebel Kalalat, and
courses nearly eastward to reach the sea in latitude 23° 52′. For
the first two-thirds of its course of about thirty kilometres,
Wadi Kalalat is shut in by high hills, and falls rather rapidly. At
its head a rough steep pass is said to exist into the head of Wadi
Shut. After passing round the north flank of Gebel Kalalat, the wadi
receives two small tributaries called =Wadi Um Maiat= and =Wadi el
Dibag lil Batoga=, the former draining the north-east face of Gebel
Kalalat and the latter the north-west face of Gebel Batoga. After
receiving Wadi Dibag, the Wadi Kalalat makes a bend northward for
about two kilometres, then turns south-eastward to the opening of
the hills on the coast-plain. About two kilometres above the point
where it leaves the hills, on the south side of the main wadi,
is a rocky gully containing the =Galt Batoga= a rock basin which
contained good water in 1907 and which is very easy of access in
a few minutes from the main wadi. About one and a half kilometres
further down, the small =Wadi Um Sellim=, draining the north-east
parts of Gebel Batoga, joins the Wadi Kalalat just before it opens on
to the coast-plain. The course of Wadi Kalalat from here to the sea,
about eleven kilometres, is ill-marked, over a sandy plain. A ruined
enclosure of considerable size, called =Garia Kalalat=, lies close
south of the wadi about seven kilometres from the sea.
=Wadi Um Goran= is a small wadi draining by many heads from the
east face of Gebel Batoga and its foot hills to the sea in latitude
23° 50′.
=Wadi Kunserob=, draining the south parts of Gebels Kalalat and
Batoga, courses at first nearly southwards, then curves round south
of Gebel Dibag, and after receiving =Wadi Dibag lil Kunserob= from
the north-west, proceeds eastward through the hills and across six
kilometres of sandy coast-plain to the sea in latitude 23° 47′.
=Wadi Abu Berigâ= is a short drainage line from among the hills to
the sea, a little south of Wadi Kunserob.
=Wadi Khoda= is an important main drainage channel some forty-five
kilometres in length, coursing a little north of eastward to reach
the sea in latitude 23° 43′. For the greater part of its length
it is shut in by high hills, only the last six kilometres being
across the sandy coast-plain. With a basin approximately 780 square
kilometres in area, it drains the mountains of Abu Dahr, Dahanib,
Shut, Reyan, Shenshef, Hindia, and Um Akra, some of which rise to
over 1,000 metres above the sea; it thus receives a fair amount of
water in rainy years, and is well supplied with trees and bushes. Its
average fall is about nine metres per kilometre.
The head of Wadi Khoda is formed by the union of three wadis,
coming approximately from the north, west, and south, in the form
of a cross. The central one of these, =Wadi Abu Debebi lil Khoda=,
heads in a very easy pass leading to Bir Betan and the old mines
of Um Eleiga. The one to the north, =Wadi Salib el Abiad=, is said
to lead into Wadi Khiua, and to possess some old mines, but has not
been explored. The remaining one of the three, =Wadi Salib el Azrak=,
drains the east face of Gebel Abu Dahr and the high hills east of
it; the feeder of it from Abu Dahr, called =Wadi Um Karaba=, leads
by an easy pass, just north of the mountain, to Bir Betan and the
Um Eleiga mines, while some eight kilometres from its junction with
Khoda a track leads up a gully south-westward over another easy pass
to Bir Rahaba. The names Salib el Abiad and Salib el Azrak refer to
the form of the wadis and the nature of their floor, _salib_ meaning
“cross,” while _abiad_ and _azrak_ refer to the prevailing white
and dark colours of the sand in the respective arms of the cross;
these colours are due to the wadis draining light-coloured granites
and dark-coloured serpentines and schists respectively.
A little below the union of the three arms above-mentioned, Wadi
Khoda expands into a small rather stony plain, where the sinuous
=Wadi Allawi=[93] enters from the north. This important feeder,
which drains the eastern face of Gebel Dahanib, is mostly shut in
by high hills, and is relatively well wooded; if it be followed up
for about ten kilometres, one comes to the tomb of Sheikh Farhan,
near which meet many small feeders, one of them containing a small
rock basin near its head.
About eight kilometres below the point of entry of Wadi Allawi,
Wadi Khoda receives two feeders from opposite sides; that from the
north, =Wadi Um Tawil lil Khoda=, drains from Gebel Dahanib, while
that from the south, =Wadi Hindia=, is a sandy rapidly-falling wadi
draining Gebel Hindia.
Some five kilometres further down, =Wadi Um Akra=, draining the
mountains of the same name, enters Khoda from the south, while another
two kilometres brings us to the place of influx of =Wadi Shut=, an
important feeder from the north. The head of Wadi Shut is on the west
side of Gebel Kalalat, whence its course is westward for about ten
kilometres; it is then joined by the =Wadi Abu Hugban=, coming from
the south-west, and from this point it runs south-south-east for some
twenty-three kilometres to its junction with Wadi Khoda. Wadi Shut is
a rather wide wadi with a sandy floor, fed by many tributaries from
the mountains of Dahanib, Um Hegilig, Reyan, and Shut. Its principal
feeder in the lower part of its course is =Wadi Um Tawil lil Shut=,
which drains the south part of Gebel Dahanib and enters Shut from
the west about five kilometres above its junction with Khoda. The
Wadi Shut has a fair growth of trees, and is said to possess also
a large water source, the exact locality of which has not, however,
been ascertained.[94]
Just below the place where Wadi Shut joins it, Wadi Khoda receives
a small feeder called =Wadi Um Gubur=, entering from the north
and marked by several graves near its mouth. On the other side,
two kilometres further on, =Wadi Shib= enters from the south, and
five kilometres further the =Wadi Um Seyal lil Khoda= enters Khoda
from the north.
The =Wadi Gumudlum=, the next great feeder of Khoda, enters from the
north four kilometres below Wadi Um Seyal. It is a wadi some eighteen
kilometres in length, coursing south-south-east, and having its head
on the west side of Gebel Kalalat. A little below wadi Gumudlum,
near a boss of white quartz, several small feeders, of which the two
principal are called =Wadi Buluk= and =Wadi Um Lassaf=, enter Wadi
Khoda from the south; these drain the north side of the high hills
called Gebel Um Etli.
The last feeder of Wadi Khoda, the =Wadi Shenshef=, enters the main
wadi some three kilometres above the place where it debouches on
to the coast-plain, or eight kilometres from the coast. It is a
narrow and very tortuous gorge winding among high hills. If it be
followed up for about ten kilometres, one comes to several small
wells called =Bir Shenshef=, which contained water in 1907, and a
little above the wells, where the wadi becomes more open, there are
ruins, called =Hitan Shenshef=, which attest the former existence
of a town or large village. The ruins are on both sides of the wadi,
and many of them are extremely well built of slabs of quartz schist;
besides the houses in the wadi itself, there are small towers on
the hills. As there are apparently no mines in the hills here, the
origin of the ruins is not clear; from the strong situation and the
watch towers, and its proximity to fresh water and the sea, it may
possibly represent an old slave dealer’s stronghold.
For some eighteen kilometres south of the Wadi Khoda, the seaward
drainages have not been explored, but they are believed to be only
short wadis, as the high mountains of Faraid are here only about
ten kilometres from the coast. From guides’ statements, the =Wadi
Um Etli=, coursing eastward and draining the south faces of Gebel
Um Etli, enters the sea in about latitude 23° 38′, and there is
probably at least one other short wadi draining to the sea about in
latitude 23° 35′ from the north part of Gebel Faraid. The sandy
coast-plain in this region is about five kilometres wide.
The =Wadi el Sorubiab=, draining from the north part of Gebel Faraid,
and the =Wadi Bint el Kurdum=, draining the mountains around the
remarkable “Bodkin” peak, enter the sea together by way of a
small lagoon in latitude 23° 30′. Another wadi, for which I could
not obtain any name from my guides, drains the extreme south parts
of Gebel Faraid and the north slopes of the smaller Gebel Fereyid,
entering the sea in about latitude 23° 19′.
=Wadi Rahaba=, with a basin of about 900 square kilometres in area,
drains the country between Gebels Faraid and Abu Dahr. From its
head, situated about six kilometres south-east of Gebel Abu Dahr,
there is an easy pass into Wadi Salib el Azrak, a tributary of
Wadi Khoda. About three kilometres below its head, a feeder called
=Wadi Titai= enters Rahaba from the hill country to the east; and
a kilometre lower down, another feeder called =Wadi Abu Nikheil=,
comes in from the west. At this point there is an important well,
=Bir Rahaba=, sunk in the alluvium of the wadi floor; this is said
to yield good summer supplies, but was filled up by downwash when I
visited it early in 1907. Some three kilometres below Bir Rahaba,
a tributary called =Wadi Abu Reye= enters Wadi Rahaba from the
north-west; and there is said to be a well, called =Bir Abu Reye=,
about one and a half kilometres up this wadi. Another feeder, the
=Wadi Um Buerat=, joins Rahaba from the south-west a little further
on, and then the wadi, which has thus far taken a southerly course,
turns south-east, winding considerably for some eight kilometres
till it is joined by its most important feeder, the Wadi el Abiad.
This =Wadi el Abiad= drains the western side of the northern peaks of
Gebel Faraid, and derives its name from the white granitic sand which
forms its floor. It has a length of some twenty kilometres and is fed
by the =Rod Elbel=, which heads in a sandy plain at the foot of the
highest peak of Faraid, and by the =Wadi Abu Ribian=, which collects
the drainage from the lower hill country west of the Bodkin peak.
About three kilometres lower down than the point of influx of Wadi el
Abiad, Wadi Rahaba receives the =Wadi Megah= as a tributary from the
north-west; a well, called =Bir el Gahlia= is said to exist at the
head of this wadi, about twelve kilometres up from its opening into
Wadi Rahaba. Some six kilometres further down, Wadi Rahaba opens out;
its course down to this point has been shut in by high hills, but now
becomes an ill-marked drainage line over a sandy plain. The plain is
broken by small hills, and is limited east and west by other hills
which increase in height further away, forming in fact the foot-hills
of Gebels Orga and Um Tenebda on the west and of Gebel Faraid on the
east. In this part of its course Rahaba receives several tributaries,
the principal being =Wadi Hutit= from the north-west, =Wadi Dagalai
lil Rahaba= and =Wadi Abu Had= from the east, and =Wadi el Marafai=,
which runs for some ten kilometres nearly parallel to Wadi Rahaba,
among low hills two or three kilometres east of the main Wadi,
joining the latter about due west of Gebel Fereyid.
Wadi Rahaba curves round to the south of Gebel Fereyid in a quadrant
of about seven kilometres radius, and then proceeds nearly due east
to reach the sea in about latitude 23° 12′.
The upper parts of Wadi Rahaba, where it is shut in by high hills,
contain many trees and bushes; but the lower parts are more barren
and sandy, the actual drainage line being in places difficult to
define on account of the paucity of vegetation and the openness
of the plain. The total length is about seventy-five kilometres,
and the total fall 450 metres; the slope averages eight metres per
kilometre in the upper twenty-five kilometres, where the wadi is
narrow and shut in, but only five metres per kilometre in the broad
and sandy course which forms the remaining fifty kilometres.
=Wadi Hodein=, one of the largest and most important of the
seawards draining wadis of the Eastern Desert, has a basin of
nearly 12,000 square kilometres, or over a square degree of the
earth’s surface. Its main channel, formed by the union of the
Wadis Arned, el Sania, Um Sumur, Saalek, Um Reit, and el Nom, in
latitude 23° 18′, longitude 34° 43′, and reaching the sea
at Bir Shalatein[95] in latitude 23° 8′, longitude 35° 37′,
has a length of 108 kilometres and an average slope of three metres
per kilometre. For the first fifteen kilometres of its course it is
shut in by the high sandstone scarps of Gebel Abraq and Gebel Hodein;
but shortly after passing the Abu Saafa Springs its channel becomes
wide and sandy, passing through lower metamorphic hill country;
and in the last twenty-five or thirty kilometres of its course it is
merely an ill-defined drainage line over the sandy coast-plain. Its
lower reaches are dreary and inhospitable, but its upper-portion
is pleasantly wooded, and contains the perennial springs of Abu
Saafa. Wadi Hodein is remarkable for the large number and length of
its tributary wadis, some of which exceed the main channel itself in
length, while many of them contain wells and form important lines of
communication by leading to easy passes over the main watershed. In
the description which follows, I shall first consider the wadis which
by their union form the head of the main channel, afterwards tracing
the course of the main wadi in detail to the sea, noting the influx
of the various tributaries on either hand, and finally describing
the larger tributaries themselves.
The most important of the wadis which join to form the head of Wadi
Hodein are Wadis Arned, Saalek, and Um Reit. These join in a small
plain with the =Wadis el Sania=, =Um Sumur= and =El Nom=, which are
smaller and will not need further mention.
=Wadi el Arned= originates on the main watershed about five kilometres
south-east of Galt el Aguz. The watershed here is only 427 metres
above sea-level, and is so flat and sandy that it is almost impossible
to say within a kilometre where the divide actually is; the wadi
in fact heads in a sandy plain about two kilometres wide with low
sandstone hills on either hand, from which feeders join the main
drainage line. About six kilometres below its head, Wadi Arned
is joined from the south by its most important feeder, the =Wadi
Muegil=. This wadi, which has a length of some twenty kilometres,
originates in the hill country about nine kilometres north of
Gebel Um Reit, where an easy pass connects it with Wadi Saalek;
it flows in a northerly direction, entirely among sandstone hills,
and is fairly provided with vegetation. Some two kilometres lower
down, Arned receives a smaller feeder from the north, called =Wadi
Um Arta=; by following this up for about five kilometres, one can
reach a rather steep and sandy eastward pass into the head of Wadi
Silsila, and this forms the shortest route from the Galt el Aguz
to the springs of Abraq. About four kilometres below the junction
of Wadi Abu Arta, near an isolated hill on the east side of the
Wadi Arned, there appears to be another opening into one of the
heads of Wadi Silsila; this opening is very sandy and looks like a
practicable alternative route to Abraq Springs, though it has not
been explored. Lower down its course, Wadi Arned is at first very
sandy and bare, with high sand-drifts swathing the feet of the hills
on the east; but it gradually narrows into a gorge and becomes less
sandy, then opens out again, and near its junction with Wadi Hodein
it contains abundant vegetation. The Wadi Arned forms the easiest
and most direct road from Abu Saafa to Daraw, _via_ Galt el Aguz,
Bir Abu Hashim, and Bir Qoleib.
=Wadi Saalek= is a short wadi with many feeders, draining the hills
round Gebel Saalek; one of its northern feeders leads to a pass into
the head of Wadi Muegil, while one of its south branches heads in
a pass leading round the west side of Gebel Um Reit to Wadi and Bir
Um Reit.
=Wadi Um Reit= heads in the granite mountain called Gebel Um Reit
and flows north-eastward, to the south of the mountain, for about
twenty-two kilometres, to its junction with Arned and Saalek to form
Wadi Hodein. The head of Wadi Um Reit leads to a pass north-west of
the mountain into Wadi Saalek, while the western head of Um Reit,
which bears the name =Wadi el Dub=, leads on to a sandy plain
forming the main watershed, whence there are easy tracks to the
various feeders of Wadi Timsah. The well called =Bir Um Reit= is
a deep excavation, in the wadi floor at the foot of the mountain,
near a large tree. Dr. Hume, who visited it in 1906, found it to
yield water of only mediocre character. It is about one hundred
kilometres by road from Bir Abu Hashim, the nearest well to the
west, but only about thirty kilometres from Abu Saafa Springs,
the nearest water eastward; to get to Abu Saafa from Bir Um Reit,
one has only to follow down the wadi, and the supply at Abu Saafa
can always be relied on for quantity and quality. Near the well,
Wadi Um Reit receives feeders draining the high granite hills of
Etresia; the principal of these is called =Wadi Malhat=. The lower
part of the course of Um Reit is almost entirely in sandstone hills;
it has not been mapped in detail except near its junction with Hodein.
We turn now to the main channel of Wadi Hodein, which originates,
as above-mentioned, by the union of the Wadis Um Reit, Saalek,
Arned, and other smaller wadis in a small plain, and shall follow
its course onwards to the sea. Three small feeders, =Talet Um Danaqa=
and =Talet Kurit= on the south, and =Talet Um Sideri= on the north,
join the channel a few kilometres below its head, while about nine
kilometres from the head there enters a larger wadi coming from
the south, called the =Wadi el Gihab=. The main Wadi Gihab has not
been followed, but its eastern branch, called =Wadi Gihab Abu Derb=,
contains a large and very easily accessible galt about four kilometres
from Hodein, and leads about ten kilometres further on, to a very
steep and difficult pass into Wadi Dif; this pass is practicable
only on foot, being risky even for unladen camels.
The =Springs of Abu Saafa= are situated in the Wadi Hodein, about two
kilometres below the point of influx of Wadi Gihab, at an altitude of
310 metres above sea-level. The Wadi Hodein is here narrow, and shut
in by very high steep sandstone scarps. There are four springs, all
issuing from the northern scarp at intervals of about sixty metres
along the wadi, and all about three metres above the wadi floor,
trickling into pools about a metre in diameter close by. The most
westerly of the four springs is a mere trickle; the next yields a
rather greater flow, from a carved niche in the rock, with a Greek
cornice; the third is the one most used, having the greatest flow
of the four, while the easternmost is almost stagnant and has yellow
incrustations near it. The rate of flow, even from the largest spring,
is very slow, probably not more than ten litres per minute, and
the overflow from the pools is only a tiny stream a few centimetres
wide which soon loses itself in the sand of the wadi floor; but the
pools are large enough for a dozen or more camels to drink from, and
soon fill up again when emptied. The water is of excellent quality,
very clear, and the supply never fails. Near the springs there are
five or six small date palms, and the wadi hereabouts has many other
trees. After rain, this part of Wadi Hodein at times becomes a stream;
this was the case in October 1907, for I found numerous pools in the
wadi floor, and scum and froth showing that an impetuous stream about
half a metre deep had flowed down the wadi only a few days prior to my
visit. Just below Abu Saafa Springs, Wadi Hodein receives the short
=Wadi Maghal= from the north-west; this wadi, which is walled in by
high sandstone plateaux, contains water holes about three kilometres
from Wadi Hodein; but these are less important than the springs of
Abu Saafa, and are, moreover, off the main road.
Wadi Hodein now opens out, the high sandstone scarps of Gebels Abraq
and Hodein running north and south-east, and enters a sandy plain
with very low hills, from among which some small feeders join the
main wadi. About fifteen kilometres below the opening of scarps,
Wadi Hodein receives, from the north-west, the Wadi Naam,[96] a
great tributary draining the mountains of Zergat Naam, Um Bisilla,
and Abu Dahr. The next influx is from Wadi Dif, which enters Wadi
Hodein from the south-west about six kilometres further on; Wadi
Dif itself is only a short wadi, but it collects the drainage
of an immense area to the south by long feeders, and contains a
good well. Nearly opposite to Wadi Dif, the =Wadi Orga el Atshani=
joins Wadi Hodein from the north-west; the Wadi Hodein has here two
large island-like masses of low hills in it, between which the main
drainage line passes. Lower down, =Wadi Orga el Rayani= enters by two
mouths from the north. Both the Wadis Orga are said to originate near
Gebel Orga, some thirty kilometres to the north, but their courses
have not been mapped; the one called El Rayani is said to lead to
a good well, =Bir Orga=, about twelve or fourteen kilometres above
its junction with Hodein. On the opposite (south) side, Wadi Hodein
receives the Wadi Anfeib, draining the high sandstone plateau of
Gebel Anfeib. A little further on the small =Wadi el Khasiya= comes
in from the north, by two channels, one on either side of a small
group of isolated hills; and nearly opposite is the mouth of Wadi
Madi, which drains the west side of the great mountain mass of Gerf,
some sixty kilometres to the south, and possesses a good well about
fifty kilometres up its course from Wadi Hodein. Several feeders come
in from the north a little further down the wadi, of which the chief
is the =Wadi Um Tenedba=, draining the mountain of the same name,
while others drain the hill country round Gebel Harhagit. On the other
(south) side is the mouth of Wadi Khashab, draining the west side of
Gebel Khashab and the hills west of it. A few kilometres further on,
Wadi Hodein widens considerably, and from here onward it is very
sandy and arid. A long spur running north-west from Gebel el Anbat
nearly cuts across the wadi, the main channel of which passes north
and east of the spur, while to the west of it is a rather broad sandy
plain with ill-marked drainage lines from the hills, of which the
chief bears the name of =Wadi Um Seleim=. Near Gebel el Anbat are
numerous small feeders of Wadi Hodein from that hill and the other
hills to the north-east. About eight kilometres below Gebel el Anbat,
Wadi Hodein quits the hills and, turning a little north of east,
merges into the coast-plain, over which its remaining course of about
twenty-seven kilometres is very ill-defined. Just where it leaves
the hills, Wadi Hodein is joined from the south-west by Wadi Beida,
draining the mountain of the same name and containing two wells;
and a little further on it receives Wadi el Kreiga, which drains the
hill country round Bir Meneiga. The junctions of Wadi Beida and Wadi
Kreiga with Wadi Hodein are very difficult to trace on the ground,
being almost lost in the general sandy plain.
=Bir Shalatein=, a very salt well in the Wadi Hodein, about two
kilometres from its mouth and only about seven metres above the sea,
is chiefly of importance by reason of its marking the administrative
limit of the Egyptian and Sudan spheres of government. It is merely
a few shallow pits sunk in the wadi bed, yielding water drinkable
only by camels. An iron beacon two metres high has been erected on
a low bank close to the well, and will enable the well, which is
itself inconspicuous, to be easily found.
=Wadi Naam=, a great tributary of Wadi Hodein coming from the
north-north-west, originates about ten kilometres south-east of
Gebel Zergat Naam by the union of the Wadis Abu Seyal, El Fil, and Um
Bisilla, and courses south-south-east for about forty-nine kilometres
to its junction with Wadi Hodein. It is a very barren wadi, being
for most of its length a broad, shallow, and very sandy drainage
line among low hills, and in its lower parts, where it crosses the
plain of Abraq, its course is very ill-marked. Its slope decreases
from five metres per kilometre near its head to about three metres
per kilometre in its lower reaches. Besides the three wadis which,
as above-mentioned, unite to form its head, Wadi Naam has several
large tributaries, of which the chief are the Wadis Silsila and Abraq
on the west, and Wadis Erf Um Araka, Arais, and Betan on the east.
The =Wadi el Fil=, which may be regarded as the main head of Wadi
Naam, though it is not the longest, drains the north-east portion of
Gebel Zergat Naam (sometimes called Hagar el Fil). The rocky gullies
forming its heads contain rock basins which yield water for a short
time after rain.
=Wadi Abu Seyal= drains the south part of the same range; its head
is very steep, and is said to contain a very large galt, which holds
supplies of water for five months after rain.
=Wadi Um Bisilla= drains Gebel Um Bisilla, which it half encircles,
its main head being north-east of the mountain, where there is an
easy pass into Wadi Abu Nilih, and thence an easy road to the head of
Wadi Lahami. About eleven kilometres west of the mountain, Wadi Um
Bisilla receives, from the north-east, the =Wadi el Khiua=, which,
with its tributaries, =Wadis Abu Fagir= and =Abu Nilih=, drains the
low hill country north of Gebel Um Bisilla. The lower parts of Wadis
Um Bisilla and Khiua have not been surveyed in detail; their courses
as shown on the map are only approximate, but being based on guides’
statements near the spot they are probably substantially correct.
=Wadi Erf Um Araka= heads as a series of small wadis among the low
hills south of Um Bisilla, and curves round westward between the
high hills of Abu Shigelat and Erf el Gimal on the north, and Erf Um
Araka or Gebel Belamhandeit on the south, to join Wadi Naam about
five kilometres lower down than Wadi Um Bisilla. The hill country
round the heads of Wadi Erf Um Araka is fairly open, so that one
can proceed freely from the head of Wadi Arais, across those of Wadi
Erf Um Araka, and on into the heads of Wadi Um Bisilla.
=Wadi Arais= originates by the union of many small feeders in the low
hill country between Gebels Um Guruf and Hendusi, and courses for the
first fourteen kilometres in a south-south-west direction. About nine
kilometres below its head the =Wadi Um Guruf=, draining the hills
round the conspicuous granite boss called Gebel Um Guruf, enters
from the north-west. Some five kilometres further on, just beyond the
place where Arais makes a sharp westward bend, =Wadi Belamhandeit=,
draining the east face of the long gneiss range called Erf Um Araka or
Gebel Belamhandeit, enters from the north. Wadi Arais now narrows into
a winding gorge, cutting westward for about ten kilometres through
the complex of high gneiss hills called Gebel Arais to join Wadi
Naam. Its junction with Wadi Naam takes place in a small plain, with
the sandstone plateaux of Gebel Um Sididad on the west and the gneiss
hills of Gebel Arais on the east. The fall of Wadi Arais is from 464
metres above sea at the pass into Wadi Erf Um Araka, to 345 metres
where it joins Wadi Naam after a course of twenty-five kilometres;
so that its slope averages four and a half metres per kilometre.
=Wadi Silsila=[97] heads in high sandstone hills on the meridian
of 34° 40′, north of Gebel Abraq, where at least one pass, steep
and sandy, leads to the Wadi Arned. Its course is almost due east,
over a plain with low sandstone banks, with a great deal of blown
sand. Feeders enter it from the sandstone hills which bound the plain,
the principal being the =Wadi Um Sididad=, draining the high sandstone
hills, called Gebel Um Sididad, on the north. About seven kilometres
before it joins Naam, Wadi Silsila cuts through the range of low
sandstone hills which stretches southward from Gebel Um Sididad to
near Abraq springs; in proceeding to Abraq from the pass at the head
of Wadi Silsila, one bears off to the south before reaching this
range, entering the drainage of Wadi Abraq over an open sandy plain.
=Wadi Abraq= is a rather ill-defined drainage line which originates
on the north side of Gebel Abraq, and after skirting the high
sandstone scarp, from which it receives small feeders, for about
thirteen kilometres, turns eastward to join Wadi Naam, about nine
kilometres above its junction with Hodein. Wadi Abraq is sandy and
barren, and would be scarcely worthy of mention but for the fact
that it contains some of the most important water sources of the
entire Eastern Desert, the =Abraq Springs=. There are no less than
five springs within a length of as many kilometres of the wadi,
yielding perennial supplies of excellent water.
The first spring from the north, called =Bir el Sunta=, is a pool
about two metres in diameter at the entrance to a little gully in
the face of the high sandstone scarp; it is very easily accessible
to camels, being practically on the plain, and fills as rapidly as
it is emptied. The second and third springs, called together =Bir
Abu Dibesat=, are about 1,500 metres south-east of Bir el Sunta,
near the tomb of Sheikh Hamid; they form smaller pools at the foot
of the scarp. The fourth spring, =Bir Abraq=, is situated a short
distance up a stony gully which emerges from the scarp a little
further south; the water lies in large pools under dipping sandstone
beds on the south side of the gully. The fifth spring, =Bir Gumbit=,
is said to be some three kilometres further south-east, and, like
the others, at the foot of the sandstone scarp; it has not, however,
been visited by the survey party.
[Illustration: Fig. 2.—Map of Abraq Springs. Scale: 5 centimetres
to a kilometre.]
The water at all the Abraq Springs is of excellent quality; it
contains masses of green algæ, but these are easily avoided in baling
out, and the water can be obtained quite clear. Of the four springs
visited, the one called Bir Abraq is the chief; but Bir el Sunta
is rather easier of access for camels. The springs are practically
all at the same level, _viz._, 330 metres above sea, and all derive
their water from the same sandstone beds. No camel food grows near the
wells, and there are very few trees in the vicinity; consequently, the
Arabs of the neighbourhood do not camp near the springs, but in Wadi
Hodein and its tributaries, drawing water from Abraq or Abu Saafa at
intervals. There are, however, ruins of a large ancient fort on a low
hill east of Bir Abraq, and some Arab graves a little further north;
among these latter is a large tomb said to be that of Sheikh Hamid.
=Wadi Betan= originates on the north side of Gebel Abu Dahr, where an
easy pass, 610 metres above sea-level, connects its head with Wadi
Um Karaba, and courses at first westward to near Gebel Hendusi; it
then turns southward to join Wadi Naam a few kilometres only above its
junction with Wadi Hodein. Its total length is over fifty kilometres,
and its average slope is about seven metres per kilometre. Only the
head of Wadi Betan has been surveyed in detail; but this is the most
important part, as containing water sources and old mine workings;
and the lower part of its course as shown on the map is probably
substantially correct, being based on statements made near the spot
by guides familiar with the district.
About five kilometres below its head, Wadi Betan contains the two
wells called =Bir Betan=. These are excavations in the alluvium of
the wadi. The lower one is at the mouth of the small Wadi Um Eleiga,
while the other is about 600 metres further up Wadi Betan, close to a
small tree. Both these wells were filled up by downwash when I visited
them in February 1907, and their places were only recognisable by the
clay “hôds” near them; at this time there was no necessity for
the Arabs to open them, as a galt at the head of the wadi, just south
of the pass into Wadi Um Karaba, was yielding a good supply of water.
Just above the wells, Betan receives from the south the feeder
called =Wadi Mistura=, draining the west side of Gebel Abu Dahr. The
little =Wadi Um Eleiga=, which drains into Betan close to the south
well, is of importance as leading to some extensive ruins and old
workings about two kilometres up from its mouth. The ruins are mostly
rubble hovels, while the workings, which were evidently for gold,
vary from mere scratchings to pits ten metres deep in the rock. A
diorite mill-stone is to be seen near the ruins.
The =Wadi Abu Debebi lil Betan=, which joins Betan on the north about
three kilometres below the wells, leads by an easy pass into =Wadi
Abu Debebi lil Khoda=, one of the heads of Wadi Khoda, and forms
the nearest way to the coast from Bir Betan. =Wadi Abu Sieiyil=
is a small feeder entering Betan from the south, three kilometres
further down. The principal remaining tributaries of Betan are the
Wadis Hefeiri, Abu Beid, and Egat. =Wadi Hefeiri= runs westward
from near the Abu Debebi pass, and turning south near Gebel Hendusi,
receives the =Rod el Hendusi= just before entering Betan. =Wadi Abu
Beid el Azrak= originates near Gebel Abu Sieiyil west of Abu Dahr,
and flows southwards to join =Wadi Abu Beid el Abiad=, which in turn
flows into Wadi Betan. A well, =Bir Abu Beid=, is situated near the
junction of Wadi Abu Beid el Abiad and Wadi Abu Beid el Azrak, where
there are numerous seyal trees; it was yielding a fair quantity of
good water in 1906. Of the =Wadi Egat=, nothing has been seen; it
is, however, stated by the Arabs to originate in the rugged hilly
tract south of Gebel Abu Dahr, and to join Wadi Betan lower down
its course than Abu Beid.
=Wadi Dif= originates in the sandstone hills round Bir Dif, and
pursues a very sinuous north-easterly course, cutting through the
high sandstone plateau which is named Gebel Hodein to the north,
and Gebel Dif to the south of it. For the major part of its length
of twenty-nine kilometres it is very narrow, with very high steep
sandstone scarps on either side, but it is a little more open near
its origin, where Wadi Feqoh joins it, and in its lower part it
winds as a broad sandy valley through the low hills which separate
the Wadi Hodein from the high sandstone plateaux; it joins Wadi
Hodein close to the meridian of 35°. Except the Wadi Feqoh, which
is of immense length, and drains a very large area, Wadi Dif has
only a few insignificant feeders. Of these, =Talet Um Karaba= and
=Wadi Enqireidia= enter from the south plateau near the place where
Wadi Dif leaves the high sandstone hills; and =Wadi Gelabat Shabai=,
coursing north-east through the low hill country flanking the plateau,
joins Wadi Dif just above its junction with Hodein.
=Bir Dif= is situated in a small gully forming the head of Wadi Dif,
in latitude 23° 12′ 42″. To a traveller coming up Wadi Dif,
Wadi Feqoh forms the main continuation of Wadi Dif, and the gully
containing Bir Dif appears to be a lateral tributary coming in
from the west; but the Arabs restrict the name Dif to the drainage
line below the spring, and apply the name Feqoh to all the upper
main channel. Bir Dif is a spring forming two pools of good water,
situated about a kilometre up the gully, at the junction of sandstone
and schists. The approach to the pools is very stony, but camels
can easily reach the water; the spring is 290 metres above sea-level.
=Wadi Feqoh=, a tributary of Wadi Dif, is many times longer than
Wadi Dif itself, and even longer than the Wadi Hodein of which Wadi
Dif is a tributary, having a length along its main channel of 150
kilometres, with feeders totalling several times that length. Though
only portions of Wadi Feqoh have been surveyed in detail, the
position of its entire course is known with tolerable accuracy from
the statements of guides at various stations from which portions
of it could be pointed out. It is for the most part a very barren
wadi, forming an ill-defined drainage line through a dreary waterless
sandy waste. Its very name, which means “devoid of nourishment,”
indicates its character. It originates near the west side of Gebel
Soaorib, only some twenty kilometres north of the 22nd parallel of
latitude, where the main watershed separates it from the feeders
of the Wadi Alaqi. From here it follows a north-westerly course,
passing between the mountains of Eir Arib and Hadal Derqa. Curving
slightly to the north, it crosses the great sandy plain west of Gebel
Korabkansi, and passes close west of the isolated mountain called
Gebel Shabih. Further on, it enters a country of low hills with sandy
interspaces, passing close west of the low range called Gebel Um el
Kalala, and then sweeps round in a great curve towards the east to
join the Wadi Dif close to Bir Dif. The fall of its bed from near
Gebel Shabih to its junction with Wadi Dif, that is, in a length of
seventy-two kilometres, is from 470 metres to 280 metres above sea,
giving an average slope of only about 2·6 metres per kilometre;
Wadi Feqoh has in fact the most gentle gradient of all the great
seawards-draining wadis.
Wadi Feqoh has many tributaries. Those near its head, and others
coming in from the western mountains through the low hill country
north of Gebel Mishbih, have not been traced; but those draining Gebel
Korabkansi and Gebel Niqrub, which are probably the most important,
have been mapped in detail. Most of the drainage from these localities
eventually finds its way into the great trunk feeder of Wadi Feqoh,
called the =Wadi Gimal=,[98] which joins Wadi Feqoh about sixteen
kilometres before its junction with Wadi Dif. The tributaries of
Wadi Feqoh are of much more interest than Wadi Feqoh itself, as they
contain in many places a fair or even relatively rich assemblage of
trees and bushes, and at least one good well, Bir Sararat Seyet.
The most southern tributaries of Wadi Feqoh which have been mapped
are =Wadi Kamoyib=, draining eastward from Gebel Wadhait, and =Wadi
Tawayib=, draining the east face of Gebel Korabkansi. These are for
the most part barren wadis each coursing for about sixteen kilometres
across a sandy plain to join Feqoh.
The main head of Wadi Gimal is called =Wadi Seyet=. It originates
between Gebel Wadhait and Gebel Dreb about latitude 22° 35′,
and by means of many feeders drains the east face of Gebels Dreb
and Gerf. The principal feeder of Wadi Seyet from the south-west is
=Wadi Wadhait=, collecting the south drainage of Gebel Korabkansi,
while on the east the =Wadi Sherefa el Gharbi=, which leads to the
important Sherefa pass, contributes the drainage from the northern
parts of Gebel Dreb and the south-west parts of Gebel Gerf. These
both join Wadi Seyet a little south of latitude 22° 40′, while
a little further down there enter from the east two small feeders
called =Wadi Delawet= and =Wadi Buyet=. The name Seyet is given to
this wadi only down to where it passes through a narrow gap between
high hills in latitude 22° 42′; below that point it is called
Wadi Gemal. Wadi Seyet is remarkably well wooded, containing an
immense number of fine large acacia trees, and presented an almost
park-like appearance at the end of 1907. It also contains a deep
well, =Bir Sararat Seyet=, excavated in the wadi floor just above
the gap between the hills above referred to. This well was full
of downwash in the winter of 1907. It is said to be twenty metres
deep and to yield plenty of good water, but at that time there was
plenty of water in galts in the mountains, and the Arabs said they
preferred to derive their supplies from these so long as they lasted,
only digging out the well when further supplies were necessary.[99]
An unnamed feeder from the west, joining Wadi Seyet just below the
well, leads by an easy pass into the head of =Wadi Hushenab=, which
drains through Wadi Sortdau into the Wadi Gemal lower down its course.
The country between Gebel Korabkansi and Gebel Niqrub Foqani,
through which the course of Wadi Gemal lies, is a gently sloping
plain with mere low banks, among which the drainage lines branch out
forming numerous loops. The main channel runs fairly straight in a
north-westerly direction, receiving =Wadis Sortdau= and =Remalib=,
draining the hills north-west of Gebel Korabkansi as tributaries on
its west side; but a sort of loop line runs off eastward and reaches
the main channel again by the =Wadi Haletiai=, which also collects
the drainage from the south parts of Gebel Niqrub Foqani. After
passing west of this last-named mountain, Wadi Gemal takes a more
northerly course; it receives an immense number of feeders from
the west and north of Gebel Niqrub Foqani, of which the principal
is called =Wadi Umeiatib=. Other feeders enter from among the low
hills on the west, the principal being =Wadi Hadelshisheib=, coming
from the neighbourhood of the dark cone called Gebel Mismih. From
Bir Sararat Seyet to its junction with Wadi Feqoh the length of the
main channel of Wadi Gemal is fifty-seven kilometres, and its fall
is from 560 metres above sea to about 310 metres, or on the average
about four and a half metres per kilometre; its slope is thus much
more rapid than that of Wadi Feqoh, though in its lower parts, where
it passes over what is almost a plain, its gradient is less than
half this average amount. The upper parts of the Wadi Gemal and its
tributaries contain as a rule a fair abundance of trees and bushes.
=Wadi Abu Hashim=, which joins Wadi Feqoh about three kilometres
above Bir Dif, commences its course near Gebel Butitelib, where an
easy pass, broad and sandy, 405 metres above sea-level, divides it
from the heads of Rod Mukrayib, a tributary of Wadi Madi. Wadi Abu
Hashim follows a north-westerly course, nearly in a straight line,
collecting principally the drainage from the western slopes of
the range of high schist hills which flank the sandstone plateau of
Gebel Anfeib. It has a length of seventeen kilometres, and an average
slope of about six metres per kilometre. It is a fairly open wadi,
without much vegetation; on its west side are only very low hills.
=Wadi Anfeib=, which enters Wadi Hodein from the south-west eight
kilometres below the point of influx of Wadi Dif, is formed by the
union of three main heads, called =Wadi Anfeib el Tawayib=, =Wadi
Atalab=, and =Wadi Mitatib=, draining respectively the northern,
central, and southern parts of the great sandstone plateau of
Gebel Anfeib. Mitatib is joined half-way down its course by =Wadi
Unfagalan=, which likewise heads in the plateau. Below the junction
of its three main heads, Wadi Anfeib has a course of only about
seven kilometres to run, through low hill country, before it joins
Wadi Hodein.
=Wadi Madi=, the next great tributary of Wadi Hodein from the south,
heads in the western side of the complex group of mountains called
Gebel Gerf, and courses in a northerly direction for over seventy
kilometres before joining Wadi Hodein in longitude 35° 7′, five
kilometres lower down Wadi Hodein than the mouth of Wadi Anfeib. The
heads of Wadi Madi are extremely complex, consisting of a multitude
of branching drainage lines, and some of them divide their drainage
with the Wadi Gemal, which enters Wadi Hodein by way of Wadis Feqoh
and Dif. The most southerly head is the =Wadi Difoteb=, draining from
the west side of Gebel Gerf in latitude 22° 39′; but only a part
of the drainage from this gets into Wadi Madi, the rest going into
Wadi Sherefa el Gharbi. A similar fate is shared by =Wadi Eirahimib=,
which heads in a slightly difficult pass, leading into Wadi Um Reddam,
about three kilometres west of the highest point of Gebel Gerf in
latitude 22° 42′; this wadi courses in a direction a little south
of west, falling very rapidly, past the hill mass of Gebel Tueiwi,
where it divides, part of its drainage going northwards as Wadi
Madi, and part crossing the plain as Wadi Buyet and joining the Wadi
Seyet. The next head of Wadi Madi to the north is formed by =Wadi
Faditiai=, which drains the high hills east of Gebel Tueiwi, and
captures a part of the drainage brought down by the above-mentioned
Wadi Eirahimib. Exactly where the name Madi commences to be applied
to the drainage is uncertain, as Arabs differ on the point, but it
is probably most correct to consider Madi as commencing just south
of Gebel Tueiwi, where the drainage of Wadi Eirahimib, with part
of that from Wadi Difoteb, divides into two parts, the lesser going
down Wadi Buyet to join Wadi Seyet, while the greater forms Wadi Madi
itself. On this basis, Wadi Faditiai is a tributary of Wadi Madi,
joining it by several openings between latitudes 22° 44′ and 22°
46′. There are numerous feeders from the low hill country both to
Wadi Faditiai and to Wadi Madi proper. After receiving Wadi Faditiai,
Madi flows in a well-defined trench, with many trees, north-west
for a few kilometres to latitude 22° 47′, where it turns sharply,
almost at a right angle, to the north-east. A kilometre and a half
beyond the bend where there is a high granite hill on the west side
of the wadi, is =Bir Madi=. This is a well sunk in the alluvium of
the wadi floor, having its mouth lined with stone slabs; in December
1907, when I visited it, the water was four and a half metres deep,
with its surface three and a half metres below the wadi floor,
and the water was good. The wadi floor here is 476 metres above
sea-level. A beacon on the granite hill overlooking the well has
the position latitude 22° 47′ 46″ N., longitude 35° 1′
38″ E., altitude 556 metres above sea. Below the well, Wadi Madi
follows a rather winding course among moderately high hills to a
little north of latitude 22° 50′, where it gets into more open
country and continues as a broad sandy valley, curving gently in a
northerly direction, to latitude 23° 5′. Beyond this point, where
it receives the Rod Mukrayib and the Wadi Kolaiqo from the west and
east respectively, Wadi Madi becomes narrower, and winds about, though
still keeping a general northerly direction, among low hill country
to its junction with Wadi Hodein. Wadi Madi has many tributaries,
the chief being the Wadis Shellal el Gharbi, Tugudbaia, Sinatib,
Atluk and Kolaiqo, and the Rod Mukrayib, which will be treated
separately further on. The upper parts of Wadi Madi and many of its
tributaries are well stocked with trees, but its central parts,
where it is wide and sandy, are more barren. Its principal head,
the Wadi Eirahimib, falls at an average rate of sixteen metres per
kilometre; from near Gebel Tueiwi to Bir Madi the average slope is
nine metres per kilometre; while in the final fifty-four kilometres
of its course from Bir Madi to Wadi Hodein, the average gradient is
rather less than six metres per kilometre.
=Wadi Shellal el Gharbi=, a tributary of Wadi Madi, originates in
the mountains about six kilometres north of the highest peak of
Gebel Gerf, where a pass connects it with Wadi Shellal el Sharqi,
a tributary of the eastward draining Wadi Radad. Flowing at first
nearly due west, Wadi Shellal el Gharbi receives the =Wadi Um Reddam=,
which collects the drainage from the north faces of the highest
peaks of Gebel Gerf. Two of the heads of Um Reddam lead to passes;
one eastward to Wadi Shellal el Sharqi, and one westward into the
head of Wadi Eirahimib. Entering a lower hill country from which it
receives numerous feeders, Wadi Shellal el Gharbi turns north-west to
join Wadi Madi about eight kilometres below Bir Madi. It has a rather
rapid fall, and contains a fair quantity of trees and bushes. Its
total length along its main channel is twenty-one kilometres.
=Wadi Sinatib=, which enters Wadi Madi about six kilometres below
Shellal el Gharbi, is a small wadi coursing north-west through the
low hill country north of Wadi Shellal.
=Wadi Tugudbaia= conveys to Wadi Madi the drainage from the dyke
country south-east of Gebel Niqrub el Foqani. It is only a short wadi,
and enters Wadi Madi nearly opposite Sinatib.
=Wadi Berendiyeb=, which joins Wadi Madi from the west about
latitude 22° 54′, drains the western flanks of Gebel Niqrub el
Foqani. It is a many headed wadi, coursing at first among the low
foot-hills of the mountain, and then crossing almost a sandy plain
to join Wadi Madi. Its length along its main channel is about twelve
kilometres. North of Berendiyeb, there are two other feeders of Wadi
Madi coming from the low hills north-east of Gebel Niqrub el Foqani;
they have no special names, being broad and sandy and without much
vegetation in consequence of their draining only low country.
=Wadi Atluk=, which flows into Wadi Madi from the south-east almost
opposite Gebel Niqrub el Tahtani, has a rather curious origin. It
arises from a splitting of the course of Wadi Korbiai, part of the
drainage of which passes eastward down Wadi Kreiga, while the other
part retains its northerly direction as Wadi Atluk. The total length
of Wadi Atluk is about twenty-one kilometres. It has not been surveyed
in detail, but for most of its course it lies in low hill country.
=Rod Mukrayib= is a many-branched wadi which drains the hilly country
between Gebel Niqrub el Tahtani and Gebel Anfeib. One of its heads
leads by an easy pass near Gebel Butitelib into the head of Wadi
Abu Hashim; another head drains the north face of Gebel Niqrub
el Tahtani; while a third drains the south end of Gebel Anfeib,
coursing between the sandstone plateau and the schist hills west
of it. From the pass into Wadi Abu Hashim to its junction with Wadi
Madi the length of its channel is fifteen kilometres, with a fall of
from 405 metres to 250 metres above sea, giving an average slope of
ten metres per kilometre. It joins Wadi Madi on the north side of an
isolated group of hills, just where Wadi Madi begins to narrow in,
about nineteen kilometres above its junction with Wadi Hodein. From
the point where Rod Mukrayib joins Wadi Madi there is a good open
road across the heads of Wadi Edunqul into those of Wadi Anfeib.
=Wadi Kolaiqo=, which joins Madi almost opposite Rod Mukrayib,
originates in the hills between Gebel Niqrub el Tahtani and Gebel
Khashab, where a pass at its head leads into the heads of Wadi
Khashab. It is a fairly wide wadi, shut in by rather high hills,
coursing west-north-west with a length of nine kilometres and a
fairly rapid fall.
=Wadi Edunqul=, a small tributary entering Wadi Madi, about ten
kilometres above its junction with Wadi Hodein, drains by numerous
gullies the south end of Gebel Anfeib, coursing a little north of
east with a length of about eleven kilometres.
=Wadi Khashab=, a tributary of Wadi Hodein, drains by many branches
the hilly country east of Gebel Beida. One of its heads leads to a
pass six kilometres due west of the summit of Gebel Beida, whence
there is a road to Bir Beida; just before reaching the pass, there
is a large quartz vein with some ruins near it. Another feeder of
Wadi Khashab, the =Wadi Dehaiartib=, heads in a pass leading to the
head of Wadi Kolaiqo. Wadi Khashab has not been explored south of
23° 0′. From this parallel to Wadi Hodein its length is about
twenty-six kilometres, but its head may be five kilometres or
more further south. The country on the west side of Wadi Khashab
consists of low hills, but on the east it drains very high hills,
and its feeders course in trenches across the stony slopes at the
feet of the hills to join the main channel. Wadi Khashab contains
large numbers of trees, whence its name (Khashab = wood). Its average
slope is about eight metres per kilometre.
=Wadi Beida= originates at a pass 395 metres above sea-level, six
kilometres west of the summit of Gebel Beida, where a road leads over
into Wadi Khashab. From the pass Beida courses south-east for seven
kilometres, receiving feeders from the high hills on either side. It
then turns abruptly at an acute angle, following a northerly direction
for one and a half kilometres; then turning east for one kilometre,
it receives a great feeder draining the south slopes of Wadi Beida,
afterwards turning south for one and a half kilometres to a point
marked by the ruin of a small well built stone structure, in which
mortar and stucco has been used. From this point the wadi follows
a winding course, at first south-east but gradually working round
into a north-easterly direction, as a narrow gorge through the high
hills of Gebel Beida. Just where the wadi begins to turn northward,
about one and a half kilometres below the ruin above-mentioned, are
the two wells called =Bir Beida=. The upper well is at the opening
of a defile leading south-eastward to a pass, forming the point
of departure in the nearest road from Bir Beida to Bir Meneiga;
this well was dry in November 1907. The lower well is about 500
metres further down the wadi, at a sharp bend in its course; it is
an excavation in the alluvium of the wadi floor, and was yielding
good water in 1907 from a depth of about six metres. The Arabs say
that the supply at this well only fails after three or four years
without rainfall, but the water only infiltrates slowly, so that
after it has been emptied by a caravan it requires a day or so to
refill. The top of the well is 205 metres above sea-level.
About four kilometres below the well, Wadi Beida emerges from the high
hills, and crosses a tract of much lower hill country seven kilometres
wide, receiving in this part of its course many feeders from the
eastern face of Gebel Beida; it then divides, still preserving its
general north-easterly direction, into a number of shallow channels
coursing across the sandy plain to join the Wadi Hodein.
From Bir Beida the nearest wells are Bir Meneiga and Bir Shalatein;
the water of the latter is, however, very salt and only drinkable
by camels. To Bir Meneiga, a distance of thirty-seven kilometres,
the track leads over the pass already mentioned south-east of the
upper (dry) well, thence into Wadi Kreiga, and up that wadi into Wadi
Meneiga; the road is rather stony near Meneiga, and rises rapidly,
so plenty of time should be allowed. To reach Bir Shalatein, forty
kilometres distant, one descends Wadi Beida into Wadi Hodein and
follows Wadi Hodein towards the sea; the road is easy, being mostly
across a falling sandy plain.
=Wadi Kreiga=, the last great tributary of Wadi Hodein, originates
by the union of the Wadis Korbiai and Meneiga, both draining that
north extension of the mountain mass of Gebel Gerf which is sometimes
called Gebel Korbiai or Gebel Meneiga.
=Wadi Korbiai= and =Wadi Meneiga= have their heads only separated by
a narrow mountain ridge, but there is no possible track over this
ridge from one to the other. In each case the wadi contains two
water sources near its head, and the limit of “navigability” of
the wadi is formed practically by these sources, above which there
are steep stony gorges.
=Bir Korbiai= consists of two wells, both situated at the foot of a
sudden drop in the rocky bed of Wadi Korbiai, about 150 metres apart,
sunk in the bouldery alluvium; there is some rude timbering at the
mouth of the wells over which a large stone is placed to prevent
infilling by downwash. In December 1907 both wells contained abundance
of excellent water, only a metre below ground level. Both wells are
easily accessible, though the road to them is stony. The wells are
stated to yield good supplies for three or four years after rain
has fallen, but after longer drought they only yield a little.
Below the wells, Wadi Korbiai sweeps round in a semicircle of about
three kilometres radius round the west flank of the hills to join
Wadi Meneiga. On its right side are the steep slopes of Gebel Korbiai,
but on the left is lower hill country. Small feeders enter from both
sides. The bed of the wadi is stony, but there are a fair number
of trees in it. Only a part of the drainage of Wadi Korbiai turns
eastward to join Wadi Meneiga in forming Wadi Kreiga; the other
part pursues a northerly course into the Wadi Atluk, a tributary of
Wadi Madi.
=Bir Meneiga= is important, not only as giving a perennial supply
of good water, but also as marking a point on the administrative
frontier of Egypt and the Sudan. It consists of two springs in the
stony bed of Wadi Meneiga, near its head. The northern spring is
taken as marking the frontier; its position is latitude 22° 47′
8″ N. longitude 35° 12′ 20″ E., altitude 605 metres above
sea-level. The southern spring is about 320 metres further up the
wadi, at a level four or five metres higher. Each of the springs
consists of a tiny pool among the rocks of the wadi floor, easily
accessible to camels. The pools only contain eight or ten gallons
each, but camels can drink as fast as they like and the pool keeps
full. The water is excellent. There are numerous ruins at Bir Meneiga;
they consist of rude rubble hovels and extend for over a kilometre
down the wadi below the springs.
Above the springs, Wadi Meneiga soon becomes impassable, ending
in rocky gorges in the mountains. Below the springs it courses for
about seven kilometres in a direction a little west of north to join
Wadi Korbiai and form the head of Wadi Kreiga. The fall in this seven
kilometres is 200 metres, so that the slope is the phenomenally rapid
one of twenty-eight metres per kilometre, and of course the floor
of the wadi is very stony and camel progress is very slow. There
are several lateral feeders, including one from the east, three
kilometres below the springs, leading to the head of Wadi Radad;
but I am not sure whether the pass is practicable as I only saw it
from the mountain top.
From the mouth of Wadi Meneiga, Wadi Kreiga courses about 15° north
of east, as a fairly wide wadi with a stony floor, with high hills on
either side from which small feeders enter. The first large feeder,
the =Wadi Abiad=, enters from the north-west, six kilometres below
the mouth of Wadi Meneiga; it is a steeply falling wadi, which, like
all wadis bearing the name of Abiad, has a floor of light-coloured
granitic sand. Some eight kilometres lower down, two feeders enter
from opposite sides: that from the north is called =Wadi Eberer=,
while that from the south bears the name of =Wadi Shigeg=. Neither of
these has been followed up far, and their length is unknown; but they
are believed to be of no great extent. Below this point the country
opens out considerably, and the wadi anastomoses round low hills,
while its floor becomes less stony and more easy under foot. The
various channels unite again about eight kilometres further down,
where the wadi receives a tributary from the north-west just before it
passes the high hill mass which forms the southward extension of Gebel
Beida. This tributary leads to an easy pass, forming a direct road to
Bir Beida. Lower down several lateral feeders come into Kreiga from
either side, and the wadi emerges on to a sandy plain with scattered
low hills. Across this plain Kreiga takes a more northerly direction
for about sixteen kilometres to join the Wadi Hodein. The length of
Wadi Kreiga from the mouth of Wadi Meneiga to Wadi Hodein is about
fourty-one kilometres. Its fall between these points is from 405
metres to about 70 metres above sea-level, giving an average slope
of eight metres per kilometre; the slope in the upper parts, where
the wadi bed is stony, is of course somewhat greater, and that in
its lower more sandy reaches is somewhat less than this average.
=Wadi Kolaiqo= is a very ill-defined drainage line heading in the
low hills called Gebel Kolaiqo, and coursing north-east for about
thirty kilometres across the sandy coast-plain to reach the sea
about latitude 23° 0′. It is very sandy, and absolutely barren
except for a little scrub in its upper parts. It would hardly have
been noticed had not the triangulation station on the hill at its
head been occupied.
=Wadi Shab=, with a basin of about 1,250 square kilometres, drains
the eastern and southern portions of the great group of mountains of
which Gebel Gerf is the centre, and reaches the sea in latitude 22°
52′, a little to the north of Mersa Shab. It has a great number of
heads, most of which bear special names, the name Shab being applied
collectively to them from the locality near the hill of Qrein Salama,
about forty kilometres from the sea, where they begin to unite
together into one great trunk channel. From the circumstance that
its heads are situated in a high mountain mass where the rainfall
is relatively great, and moreover have steeply falling stony beds
which absorb but little of the precipitation, the upper portions
of Shab and its feeders are well stocked with trees. Only in the
last stages of its course to the sea, where the absorption of its
drainage by the sandy coast plain becomes great, does the abundance
of vegetation fall off and the channel become barren. Its principal
heads and feeders are Wadi Radad (fed by Wadi Shellal el Sharqi),
Wadi Tikosha, Wadi Muqur (fed by Wadi Ti Ilak), Wadi Qadiloi (fed by
Tilat Tihu Shana), Wadi Baaneit, Wadi Kilanai, Wadi Um Saha, Wadi
Diqdib, Wadi Sherefa el Sharqi, and Kwat Hewah. At least three of
these contain good water sources, Bir Muqur, Bir Baaneit, and Bir
Diqdib being situated in the upper parts of the wadis bearing the
same names. The various heads and feeders of Shab will be described
in detail below, commencing from the northernmost one.
=Wadi Radad= may be more properly described as a tributary than as
one of the heads of Wadi Shab, as it joins the trunk wadi some fifteen
kilometres below the other feeders. It originates in a rugged tract of
high hills near Bir Meneiga, and courses eastward for about thirty-six
kilometres, joining Wadi Shab on the coast-plain near the low hills
of Ti Qireira, about twenty-four kilometres up from the point where
Wadi Shab enters the sea. It has not been surveyed in detail, but
its course was mapped from the triangulation station of Gebel Gerf
and from other occupied stations whence portions of it were visible.
=Wadi Shellal el Sharqi=, a large feeder of Wadi Radad, originates
in the mountains between Bir Diqdib and Bir Muqur. It has many heads,
the best known of which is one coming from the west, leading to a pass
into Wadi Shellal el Gharbi, a tributary of Wadi Madi; while another,
a little further south, leads to another pass into Wadi Um Reddam and
forms a possible road to Bir Sararat Seyet. Wadi Shellal el Sharqi
follows generally a northward course, with a rapid fall, and joins
Wadi Radad about eighteen kilometres below the head of the latter.
=Wadi Muqur= heads in the eastern mountains of the Gerf group, which
are sometimes called Gebel Muqur. Here the drainage from several
steeply falling rocky gullies collects into a single winding gorge
shut in by the mountains. The limit to which camels can go up the
gorge is marked by a well called =Bir Muqur=. At the time of my
visit to this, in February 1908, the well was filled up by debris,
through which, however, the water constantly rose and trickled
into pools in a series of rock basins at slightly lower levels. The
flow was at the rate of about five litres per minute, the overflow
from the basins running to waste at this rate in the sand of the
wadi. The water was of excellent quality. The Arabs state that
when the water ceases to flow as a spring they dig out the debris
and use the place as a well. Below the well, Wadi Muqur pursues a
winding course north-eastward for about two and a half kilometres;
then, receiving the short =Wadi Ti Ilak=, draining the mountains
to the west, it turns sharply eastward and emerges from the high
hills into lower country about three kilometres further on. In the
lower country the wadi changes its direction to east-north-east,
receiving many feeders from among the low hills west of Qrein Salama,
and its bed divides and anastomoses into a series of channels, which
eventually unite just before it enters Wadi Shab, five kilometres
north-east of Qrein Salama. From near its head at Bir Muqur to its
junction with Shab, Wadi Muqur has a length along its main channel of
about nineteen kilometres; it falls from 470 metres above sea-level
at the well to 200 metres at its junction with Shab, so that the
average gradient is about fourteen metres per kilometre.
A few kilometres before reaching Wadi Shab, Wadi Muqur is joined
by the =Wadi Tikosha=, draining the moderately high hills which lie
between Wadi Radad and Gebel Muqur, and winding among low hills over
the plain.
The =Wadis Qadiloi= and =Baaneit= drain from the east faces of Gebel
Muqur and the mountains and hills close south and east of it, into
Wadi Shab. There is an eastward extension of hills from Gebel Muqur,
partly drained by =Tilat Tihu Shana=, which flows into Wadi Qadiloi;
south of this extension there is a sort of bay, occupied by lower
hills separating Wadi Qadiloi from Wadi Baaneit, through which several
cross channels connect the two wadis. =Bir Baaneit= is a small well
in Wadi Baaneit, near its head; it is said to yield water always,
but refills slowly, so that only six to ten camels can be watered
at once. A little below the well, Wadi Baaneit leaves the hills
and courses north-east across a rapidly falling stony plain. On the
plain, south of the main channel, are the two ruins called =Darahib
Baaneit=. They are built of rubble stone set in plaster, with stucco
facing in places, and appear to be ancient Moslem tombs, the larger
one having evidently once supported a dome; there are about twenty
Arab graves near the ruins.
South of Wadi Baaneit the plain is crossed by many drainage channels
coursing north-east to join Wadi Shab, and the plain is covered here
with quite a park-like growth of acacia trees. The principal channel,
which comes from the hills about four kilometres south Bir Baaneit,
is called =Wadi Kilanai=.
A little south of Wadi Kilanai the plain cuts far back to the west,
and the drainage entering this portion comes from the heart of the
Gerf mountains to the north-west. A large isolated granite hill-mass
called Kilia Arib and numerous smaller hills break the monotony
of the plain and cause much branching and looping of the drainage
channels. The principal artery draining the south parts of Gebel
Gerf is the =Wadi Diqdib=, which originates on the south flanks of
the highest peaks, right in the heart of the mountain mass. In one
of the heads is a well called =Bir Diqdib=, which, though of great
service to the Koatil Arabs who inhabit this district with their
camels and other animals, is of little importance to the traveller
because of its situation in a closed-in wadi and thus not being on any
route. From its head, Wadi Diqdib courses south-westward for fifteen
kilometres or more among the mountains, receiving many feeders, before
it emerges on to the plain. On leaving the mountains it splits up,
part of its drainage going round by the north side of Kilia Arib, and
part by the south, in each case by a number of anastomosing channels.
The =Wadi Um Saha= drains the hills south-west of Bir Baaneit, and
after coursing southwards among the mountains turns the corner and
runs north-east across the plain to Wadi Shab.
=Wadi Sherefa el Sharqi=, which drains the south portion of the
Gerf _massif_ and the north-east flanks of Gebel Dreb, heads in the
important Sherefa pass, 807 metres above sea-level, and forming the
direct route from Gebel Hamra Dom and Gebel Um Rasein to Bir Sararat
Seyet by way of Wadi Sherefa el Gharbi. The pass is a fairly easy
one, though the fall is rapid, especially on the east side, where
Wadi Sherefa el Sharqi falls no less than one hundred metres in
the first two kilometres of its course. A feeder which enters Wadi
Sherefa el Sharqi from the south about two kilometres below the pass
is said to lead by another pass to a well called =Bir Bint el Dreb=,
situated at the head of =Wadi Dreb=, a tributary of Wadi Feqoh. For
the first seven kilometres of its east-south-easterly course below
the pass, Sherefa el Sharqi is shut in by very high hills, from
which numerous feeders join it; it then divides just before reaching
the great white granite hills called Eir Arib, part of its drainage
going southward to join Kwat Hewah, and part continuing its course on
the north side of the granite hills to join Diqdib near the granite
cones of Tibashoi and thence turning northwards over a large sandy
plain to enter Wadi Shab.
=Kwat Hewah= drains the eastern flanks of Gebel Dreb and the north
flanks of G. Medarai. Its heads unite to form a series of channels
in a small plain south-west of Eir Arib, and here it receives a
contribution from Wadi Sherefa el Sharqi as mentioned above. As it
passes Eir Arib, Kwat Hewah divides, part of its drainage curving
round to the north to join that of Wadi Diqdib and Wadi Sherefa el
Sharqi on its way to Wadi Shab, and the remainder going south-west
to join the Wadi Medarai. From the head of Kwat Hewah there is said
to be an easy pass into the Wadi el Krim, a tributary of Wadi Feqoh.
=Wadi Ibib=, which drains the eastern slopes of Gebels Medarai,
Abu Hireiq, and Abu Hodeid, and the eastern and northern faces of
Gebels Soaorib, Adar Qaqa, Leqaq, Um Seleim, Qidmib, Orgem, and Um
Bishtit, as well as Gebel Hamra Dom and the smaller hills south of
it, is formed by the union of the Wadis Hasium and Medarai, a little
east of Gebel Um Rasein, and enters the sea at Mersa Shab. It has
a drainage basin of about 1,800 square kilometres. Including Wadi
Hasium, which is simply the upper portion of Ibib, its total length
along its main channel is slightly over one hundred kilometres. Its
principal tributaries are the Wadis Shinai, Abu Hodeid, Abu Hireiq,
Medarai, Soaorib, and Um Bishtit.
=Wadi Hasium=, which forms the upper portion of Wadi Ibib, originates
on the main watershed in about latitude 22° 10′ and longitude
35° 15′; a pass leads from its head on to a stony plain, whence
a track leads to Miti Kwan, a tributary of Wadi Alaqi. Near its
head, Wadi Hasium contains a small well called =Bir Kagog=. A few
kilometres further down, the short =Wadi Mantil Hasium=, draining
the western face of Gebel Adar Qaqa, enters from the east, while
the =Wadi Hilwit Hasium=, draining the mountain of the same name
and containing a galt near its head, joins Wadi Hasium from the
west. Continuing its course northward past the mountains of Adar
Qaqa and Leqaq, Wadi Hasium enters an extensive sandy plain, open
to the north, bounded on the west by the mountains of Abu Hodeid
and Um Rasein, on the south by those of Leqaq and Um Seleim, and on
the east by those of Qidmib and Orgem. This plain, which averages
fifteen kilometres in width, is broken by low hills, the principal
of which, Gebel Hamra Tit, Kulet Meiqrum, and Kulet Tinasal, rise
to considerable heights. Hasium courses slightly east of north near
the western edge of this plain to near Gebel Um Rasein, then curves
to the east across it, receiving the Wadi Medarai and becoming Wadi
Ibib. In its northward course through the plain, Wadi Hasium receives
a number of important tributaries from the western mountains, besides
a few smaller feeders from the mountains to the south and from the
hills on the plain. These may be briefly described in order.
=Wadi Shinai=, draining the hills south of Gebel Abu Hodeid, courses
a little south of east and enters Wadi Hasium about latitude 22°
19′; it has not been surveyed in detail, but it contains a well
known water source, =Bir Shinai=, which is said to be about seven
kilometres from its junction with Hasium.
=Wadi Delawet=, another small feeder which likewise drains the hills
south of Abu Hodeid, and enters Wadi Hasium about three kilometres
below Wadi Shinai, is of importance as leading to a camel track over
hills which forms the means of access to =Bir Odis Maaleq=, I have not
visited this water source, but it is said to yield immense quantities
of good water, and to be situated at a rather high level in the head
of a small wadi called =Wadi Odis=, a tributary of Abu Hodeid. It
appears to be a spring fed by the rainfall on the surrounding high
mountains, the overflow filling large rock basins. The reason why it
is approached by the Wadi Delawet and the track over the mountains,
instead of by ascending Wadi Abu Hodeid and the Wadi Odis directly,
is that the latter route is very difficult for camels owing to the
steep and stony nature of the wadi floor; it is, however, possible
to use this route on foot. As nearly as I could make out from my
guides’ statements, the total distance of Bir Odis Maaleq from the
mouth of Wadi Delawet is about nine kilometres, of which the first
four are in the Wadi Delawet and the remaining five on the hill
track. The distance by the other route from Bir Abu Hodeid is about
four kilometres, some of which is climbing. My native assistant,
who was sent to erect the beacon on Gebel Abu Hodeid, took two and
a half hours to go on foot from Bir Abu Hodeid to Bir Odis Maaleq,
and estimated the latter spring to be some 150 metres higher than
Bir Abu Hodeid.
=Wadi Abu Hodeid=, which drains the mountain mass of the same name,
lies to the east of the highest peaks of Gebel Abu Hodeid and is shut
in between them and another high range further east. It has a general
south-south-easterly direction, and a very rapid fall. Its principal
feeder is the short Wadi Odis above referred to, which falls into
it from the west about six kilometres below its head. About one and
a half kilometres below the point of influx of Wadi Odis, there is
a large and important spring of good water in the wadi, called =Bir
Abu Hodeid=. Though I have not visited this spring, its situation is
shown on the map with tolerable accuracy, as its position with regard
to neighbouring triangulated points was indicated by the guides. My
native assistant, who passed the spring on his way to erect the beacon
on Gebel Abu Hodeid, reported it to be very similar to the springs
of Abu Saafa in appearance, though the latter are in a different
rock. From its position in the midst of high mountains, Wadi Abu
Hodeid must at times of rainfall collect a great deal of water, and
this explains the constant supplies yielded by the spring. Above the
spring, the steepness of the wadi renders its ascent very difficult
for loaded camels, and there is no road through its head, but guides
state that there is good grazing at certain seasons in its upper
parts, and animals are taken there to feed. Below the spring, the
wadi opens out and curves eastward round the foot of the remarkable
rounded peak of Abu Hodeid Oqla to join Wadi Hasium on the plain.
The =Rod Anut Berer=, which joins Wadi Hasium about the same point
as Wadi Abu Hodeid but from the opposite side, drains the mountains
of Leqaq and Um Seleim which bound the plain to the south.
=Wadi Tikraneib=, a small wadi full of trees, drains a jagged range
north of Abu Hodeid Oqla, and joins Wadi Hasium on the plain by
several channels.
=Wadi Abu Hireiq=, draining the mountains of the same name, originates
about latitude 22° 27′. On leaving the high mountains its channel
divides, part of the drainage going north-east as Wadi Merdiyeb,
and part south-east as Wadi Abu Hireiq. This latter wadi passes
between the main mountains and a high isolated range of hills for
about seven kilometres, then curves round to the eastward to join
Wadi Hasium. There are numerous loopings and branchings of the wadis
in this neighbourhood, caused by the feeders from the hills and
by the presence of isolated hill masses, which the drainage lines
frequently encircle, and it becomes impossible to say which of the
various channels is the main wadi, so that the name Wadi Abu Hireiq
is applied to all of them collectively.
=Wadi Odruk= is a small wadi draining between two groups of high
hills south-west of Gebel Um Rasein; it joins one of the channels of
Wadi Abu Hireiq about four kilometres above its junction with Hasium.
=Wadi Nilateib=, another small wadi further north, drains the
south end of Gebel Um Rasein and the north-east faces of the hills
close south-west of it. Coursing at first south-east for about three
kilometres, it then curves round the foot of Gebel Um Rasein to join
Wadi Hasium by two channels. There is a clear passage from the heads
of both Wadi Odruk and Wadi Nilateib into Wadi Merdiyeb. All the wadis
hereabouts contain plenty of trees and scrub, especially in their
upper parts; as Wadi Hasium is approached they become more sandy
and barren. It is, of course, the presence of vegetation available
for grazing which determines the possession of a name by such small
wadis as these two.
The drainage from the east face of Gebel Um Rasein joins Wadi
Hasium directly by many small channels, which appear not to bear
any special name.
=Wadi Medarai=, which forms the Wadi Ibib by its junction with Hasium,
ten kilometres due east of Gebel Um Rasein, has its main head in Gebel
Medarai, its length along its main channel being about twenty-five
kilometres. By numerous tributaries, many of which contain abundance
of trees and scrub, it drains the whole of the high hill country
between Gebel Medarai and Gebel Um Rasein, and it also takes a part
of the drainage from Kwat Hewah. One of its heads is said to lead
to a rather difficult pass, south of Gebel Medarai, into the =Wadi
Kirwau=, a tributary of Feqoh. For the first ten kilometres or so
of its length, Wadi Medarai courses a little north of east; it then
receives the feeder from Kwat Hewah above referred to, and changes
its direction to a little south of east, passing close north of Gebel
Um Rasein on its way to join Wadi Hasium on the sandy plain of the
numerous feeders of Wadi Medarai from the hills west and north of
Um Rasein, the principal is =Wadi Merdiyeb=, which originates ten
kilometres south-west of Gebel Um Rasein by the splitting of Wadi
Abu Hireiq. From this point of origin, it runs in a north-easterly
direction in a rather sinuous course among the hills for about twelve
or thirteen kilometres, joining Wadi Medarai close north of Gebel Um
Rasein. Another little feeder of Wadi Medarai, though only about two
kilometres long, is of some importance from its leading to =Bir Um
Rasein=, a small well among the north foot-hills of Gebel Um Rasein.
Vegetation ceases to be abundant both in Wadi Medarai and in Wadi
Hasium before their junction to form Wadi Ibib, and Wadi Ibib itself
is for the most part a barren sandy ill-defined channel coursing
north-eastward across a dreary plain for some fifty-seven kilometres
to Mersa Shab. In this fifty-seven kilometres its fall is very nearly
300 metres, giving an average slope of only a little over five metres
per kilometre. The slope of the lower part of Wadi Hasium is rather
steeper than this, while that of Wadi Medarai is about twice as great.
But though Wadi Ibib itself is barren, it has some great tributaries
which contains abundance of trees and scrub in their upper reaches,
as well as several wells. The principal of these tributaries are
the Wadis Soaorib and Um Bishtit, which with their feeders drain
the mountains of Soaorib, Qidmib, Orgem, and Um Bishtit, while other
smaller tributaries drain the lower hills north-east of Um Bishtit
and Gebel Hamra Dom.
=Wadi Soaorib= originates in the midst of high mountains a little
south of latitude 22° 10′, between the southern portion of Gebel
Soaorib and the range which extends southwards from Hadal Aweib
Meisah. At its head is a difficult pass westward into the head
of Miti Kwan, a tributary of Alaqi. Curving at first eastward,
it soon takes on a north-westerly direction, and in latitude 22°
11′ 30″ reaches a small open space called =Mitba=; here it is
met by several tributary wadis of which the principal is the =Wadi
Haiyo=, draining the eastern slopes of Gebel Soaorib. From Mitba
the direction of Wadi Soaorib becomes more northerly, and about
nine kilometres below Mitba it turns to the west, emerging from
the mountains into the more open country which forms the south
end of the great plain already referred to. Here it is joined by
the =Wadi Hankuk=, draining north-eastward from Gebel Adar Qaqa,
and a few kilometres further on by the =Wadi Dishlo=, which drains
the western flanks of Hadal Aweib Meisah and enters Soaorib from
the east. About three kilometres below the point of influx of
Wadi Dishlo, Wadi Soaorib is joined from the south-west by another
tributary which drains the west side of Gebel Um Seleim. From this
point onwards, Wadi Soaorib courses a little east of north in a
not very well defined course for about twenty-two kilometres over
a gently falling sandy plain, joining Ibib to the north-west of the
sand-swathed hills called Baqari Daba. In this part of its course,
Wadi Soaorib receives small feeders from among the hills west of it
on the plain, the principal of them draining north-eastward between
the hills called Kulet Meiqrum and Kulet Tinasal. It also receives
more important tributaries from the mountains to the east of it,
the principal of these being the Wadis Eimya and Qidmib. =Wadi Eimya=
drains the western face of Gebel Qidmib, while =Wadi Qidmib= drains
the northern parts of the same mountain. Wadi Qidmib has two main
heads; the western one lies between two high mountain ridges, and
contains a well called =Bir Qidmib=, while the eastern one leads to
a steep pass by which Wadi Meisah can be reached. Before reaching
Wadi Soaorib, Wadi Qidmib is joined by other feeders draining the
western flanks of Gebel Orgem and Baqari Daba.
From its head at the pass into Miti Kwan to its junction with Ibib,
Wadi Soaorib has a length of about fifty kilometres. The level of
the pass is unknown, but from Mitba to Ibib the level of the wadi
floor falls from 505 metres above sea to 260 metres in a length of
about forty-one kilometres, giving an average slope of six metres
per kilometre. Most of the upper portions of Wadi Soaorib and its
tributaries are well stocked with trees and bushes, but as the wadi
crosses the sandy plain it becomes more and more barren. The place
where it enters on the plain in latitude 22° 20′ marks a tribal
boundary, the upper parts, including Wadi Dishlo, belonging to the
Balgab Arabs, while the lower parts, including Wadis Eimya and Qidmib,
are Kurbeilab territory.
=Wadi Um Bishtit=, which joins Wadi Ibib some five kilometres lower
down its course than does Wadi Soaorib, heads in a small open space
in latitude 22° 26′ and longitude 35° 35′. At its head there are
two easy passes, one leading northward into the head of Wadi Habliai,
another tributary of Wadi Ibib, and the other southward into the
heads of Wadi Meisah. Just below its head Wadi Um Bishtit is joined
by the small =Wadi Delawet=, draining the hills close to the south;
while a little lower down is another small tributary from a rocky
gorge among the south hills, which is important as leading to =Bir
Um Bishtit=. This well, which was filled by downwash when I visited
it in March 1908, is situated in the floor of the gorge at a sharp
bend, about a kilometre up from the main wadi. According to the
guides, it requires excavating about five metres deep, and yields
water in quantity for about a year after rain, but when there has
been no rain for a year only small supplies can be got, as it fills
slowly; at the time of my visit there was no necessity to open the
well because there was plenty of water in galts in the mountains of
Meis-heit-ar, a little further south. The well is easy of access,
and lies at 330 metres above sea-level.
The total length of Wadi Um Bishtit is about fourteen kilometres. In
the first half of its course it runs north-westward, shut in by
high hills, and contains abundance of small trees. After cutting
through the hills it receives the Wadi Orgem from the south, and
turns northward in opening country to join Wadi Ibib north of the
hills called Adar Aweib Um Bishtit. Its average slope is about nine
metres per kilometre.
=Wadi Orgem=, which joins Wadi Um Bishtit about four kilometres
below the gorge containing the well, has its head at an easy pass
near the remarkable peak of O Shakafa; this pass leads into Wadi
Meisah, about three kilometres above Bir Meisah. From the pass,
the Wadi Orgem runs between the high hill ranges of Orgem and Um
Bishtit, in a direction a little west of north, for about sixteen
kilometres to its junction with Wadi Um Bishtit.
=Wadi Habliai=, which heads in an easy pass about three kilometres
east of Bir Um Bishtit, and runs northwards for about ten kilometres
to join Wadi Ibib, is a broad sandy and rather barren wadi draining
gneiss hills; the hills on the east are much lower than those on
the west, and their feet are swathed in drift sand.
The last feeders of Wadi Ibib are those draining from the isolated
range of high granite hills called Gebel Hamra Dom. These feeders
are very numerous, some coming from the west side of the hills and
curving round its south end to join Wadi Ibib, while others from the
east side course east and north-east over the plain directly into Wadi
Ibib. They contain numerous small trees near their heads, and after
rain there springs up short grass in this locality, affording for
short periods grazing for great flocks of sheep. The most northerly
drainage channel from the east side heads in the hills a little north
of the highest peaks, and here, after rain has fallen recently,
shallow wells are dug in the sand and yield good water. The place
where the wells are is called =Ti Dabei Hamra Dom=. One cannot rely
on getting water there for long after rain has fallen, as the supplies
are soon exhausted. In January 1908, I heard that water and grass were
extremely abundant, and large numbers of Arabs were encamped there
with their flocks and herds. But when I reached the place at the end
of the next month, most of the grass had been eaten up; only a few
Arabs remained, and these were baling out the last drops of water
from the holes to fill their skins preparatory to forsaking the place.
=Wadi Meisah=, which drains the north and east slopes of Hadal
Aweib Meisah, the eastern slopes of Gebel Qidmib, and the mountains
of Meis-heit-ar, besides the lower hills of Titailibab, Tahaqayet,
and Eqrun, has a total length along its main channel (including Wadi
Awitla, the central one of its three main heads) of about seventy-five
kilometres, and enters the sea about latitude 22° 45′.
Wadi Meisah has three main heads, called by separate names. The most
northerly is the =Wadi Sarobaiya=, draining from between Gebels Qidmib
and Meis-heit-ar; one of the heads of this leads to a steep pass into
Wadi Qidmib. The central head, =Wadi Awitla=, drains the north slopes
of Hadal Aweib Meisah. The southern head, the =Wadi Lasewid=, drains
the eastern slopes of Hadal Aweib Meisah and the lower hills to the
east of it; by ascending its southern feeders, one can pass easily
into the heads of Wadi Baueiwai, while one of the gullies opening
into it from Hadal Aweib Meisah contains a series of rock basins and
a small spring called =Megwel Um Edwa=, rather difficult of access
for camels, which was yielding fair supplies of water in April 1908.
These three heads, each of which has numerous feeders, join together
in a small plain at the south-east foot of O Shakafa, a remarkably
prominent peak practically isolated from the mountains near it,
and from this point onwards the main drainage channel is called
Wadi Meisah. The little plain where the three head wadis unite is
covered with trees, and has almost the aspect of a park; it is 455
metres above sea-level. Curving eastward and northward close round
the foot of O Shakafa, Wadi Meisah receives from the south the
=Sarob Kwan=, a short and very broad wadi leading to an easy pass
into Wadi Didaut, and then winds about as a narrow gorge shut in
by high hills. Just where it leaves the foot of O Shakafa, there
is a track from the east side of the wadi over a very easy pass
into the head of Wadi Orgem. =Bir Meisah= is a well sunk in the
alluvium of the wadi bed about three kilometres below O Shakafa,
and 410 metres above sea-level. When I visited it in March 1908,
it was filled with downwash, and as there was plenty of water in
the rock basins of the mountains further north there was then no
necessity to dig it out. The Arabs say the well is about ten metres
deep, and its water is not so good as that obtainable from the galts,
so that they only open it when the other sources in the neighbourhood
are exhausted. Two gullies entering Wadi Meisah from the east, just
below the well, each contain large galts, called =Meis-heit-ar=, a
short distance up from their mouths; these were both yielding good
and plentiful water supplies in the spring of 1908. After winding
about among the hills for ten kilometres below the well, Wadi Meisah
receives a feeder from the west having three heads. The northern
one, =Akla Da-Aiyob=, is a very sandy gully, in fact it is choked
by drift sand, and all the trees in it are dead. The central one,
coming westward from among high hills, is called =Hanqun Ra-ub=,
while the southern one, called the =Wadi Eqaiyib=, is only separated
from Meisah at its head by an easy pass, so that it almost forms a
loop of Meisah itself. To go from Bir Meisah to Bir Um Bishtit, one
crosses this pass into Wadi Eqaiyib, then up Akla Da-aiyob, and over
another easy pass at its head into Wadi Um Bishtit; the total distance
between the two wells by this route is only sixteen kilometres.
In its lower stages Wadi Meisah traverses broad open sandy spaces
between low hills, receiving a number of small feeders from either
side. It curves round to the eastward a little south of the hills of
Eqrun and then courses in a north-easterly direction across the sandy
coast-plain to the sea. In the last stages of its course its channel
is very ill-defined, the drainage spreading over the plain. The trees,
which are fairly abundant in its upper parts, become fewer as one
descends, but its lower portions are not always entirely barren, for
after recent rain short grass springs up in its broad shallow bed and
affords a moderate amount of grazing for sheep. The slope of the wadi
floor just below the well is about ten metres per kilometre; lower
down, the gradient gradually lessens, and in the last forty kilometres
of its course is only a little over five metres per kilometre.
=Wadi Kiraf=, the next wadi to enter the sea south of Meisah, is
really the terminal portion of the great =Wadi Di-ib=, the name Kiraf
being only applied to the drainage from the point of junction of the
Wad el Qireira with Di-ib to the sea, that is, for a distance of some
thirty-one kilometres up from its mouth. The Wadi Di-ib is probably
the most important and remarkable of all the seawards draining wadis
of the Eastern Desert of Egypt and the Northern Sudan. I have only
seen that terminal portion of its length which lies in Egypt, that
is, north of the 22nd parallel; but the examinations of that length
(the part of it lying within Egyptian territory, including Kiraf,
is some eighty-five kilometres) is enough to show that the wadi must
drain an enormous basin, for the average slope is the remarkably
small one of two metres per kilometre, and the wadi floor in many
places, instead of being sandy, consists of mud similar to that of
the Nile Valley. According to the “Sudan Handbook,” it rises far
to the south, probably near the 20th parallel, and flows generally
northwards, so that its length must be well over 300 kilometres. Just
before it enters Egypt proper, there is an expansion in its bed
covered with rich alluvial mud, on which crops of _durra_ are grown;
my camels were fed for some weeks on _durra_ obtained from this source
whilst I was working in the neighbourhood. In the present volume I
shall only deal with that portion of Di-ib and its tributaries which
lie north of the 22nd parallel, describing first the main channel
and afterwards its principal tributaries.
Wadi Di-ib enters Egypt a little west of the 36th meridian, as a
broad sandy drainage channel with many trees. Its bed is here only 170
metres above sea-level. Wadi Di-ib receives two feeders from the east
near the 22nd parallel; the Wadi Shendib,[100] draining the western
flanks of the high mountain mass of Gebel Shendib, is believed to join
Wadi Di-ib a little south of the frontier, while the Wadi Hareitra,
draining the north-eastern flanks of Gebel Shendib and the western
slopes of Gebel Hanquf, probably enters Di-ib a little north of
it. For the first eighteen kilometres of its course north of 22°,
Wadi Di-ib flows northward over a sandy plain, with low hills and
ridges, their feet often swathed in drift sand, on either side. It
then receives an important tributary from the west, called Wadi el
Qurat, draining the north slopes of Gebel Shiab and the hilly country
between Gebel Mashushenai and Adar Aweib. After receiving Wadi el
Qurat, Wadi Di-ib enters mountainous country, being shut in for some
fifteen kilometres by Adar Aweib on the east and Gebel Balatitda
on the west. In its northerly course here Wadi Di-ib receives many
feeders from the hills, of which two entering from opposite sides
near Bir Meheriqa are of interest. That from the east is really a
drainage channel from the sandy plain south of Gebel Sul Hamid; but
it is choked by huge accumulations of drift sand so that the drainage
never reaches Wadi Di-ib, but accumulates in a depression called O
Harbub, about four kilometres above its mouth. This channel, though
very sandy, is quite a practicable road, as I found by traversing
it on my way to Gebel Elba from Bir Meheriqa. The feeder from the
west, which enters Wadi Di-ib about one and a half kilometres below
Bir Meheriqa, is called =Wadi Salalob=; it drains the north face
of Adar Aweib, and heads in a very steep pass into Wadi Wieqwer. I
managed to get my riding camel over this pass only with difficulty
when unmounted, and it is quite impracticable for loaded camels;
the rise in the last kilometre before reaching the top of the pass
from the direction of Wadi Di-ib is over one hundred metres, the
summit of the pass being 315 metres above sea-level.
=Bir Meheriqa= is a spring situated in the mouth of a small gully at
the foot of Gebel Balatitda, close to the east side of Wadi Di-ib,
and practically on the same level as the wadi floor (120 metres above
sea-level), so that it is extremely easy of access. The floor of the
gully is covered with conglomerate of recent formation and in this are
several holes with pools of clear water about one metre in diameter
by twenty centimetres deep, which fill as fast as emptied. The water
is rather salt, but is drinkable. The portion of Wadi Di-ib which
lies among the mountains has a floor of sandy mud, with abundance
of trees and plants, among which several gazelles were grazing as
I passed through.
About six kilometres below Bir Meheriqa, Wadi Di-ib is joined from
the west by Wadi Warabeit, which drains a rather large extent of
high hills to the west and cuts through the hills north of Adar
Aweib to reach Wadi Di-ib. This wadi forms the route to Bir Meisah
from Bir Meheriqa _via_ the well known easy passes of Bani Sana and
Sarob Kwan; the total distance is about sixty-five kilometres.
Soon after receiving Wadi Warabeit, Wadi Di-ib gets into lower hill
country, with great accumulations of drift sand. From near Gebel
Tishushi Tiboki it receives the =Wadi Qumad Lim= from the north-west,
and then after passing the extensive group of low hills of Tishushi
it is joined by the Wad el Qireira, which drains a large area east
of Hadal Aweib Meisah.
From its junction with Wad el Qireira to the sea, Wadi Di-ib is
called by the special name of Wadi Kiraf. It is merely an ill-defined
drainage channel coursing north-east across a great sandy plain
for a distance of thirty-one kilometres to the sea, with only one
insignificant feeder, =Halal Hendiyeb=, joining it from the westward
close to the dark little hill called Einiwai. The Wadi Kiraf is almost
barren, the great accumulations of sand about the lower parts of Wadi
Di-ib probably absorbing most of the drainage. But to the west of the
mouth of Kiraf there is quite a dense growth of bushes and trees,
covering a large tract and visible from low hills at considerable
distances. This locality is called =Shekra el Delam=; I did not visit
it, but the Arabs say there is no wadi there, and it is possibly
due to the drainage of Wadi Kiraf running below the surface of the
sandy plain and being dammed back by the sea. A salt well, called
=Bir Adal Deib=, exists close to the shore in the same locality.
Of the =Wadi Shendib=, only a few of the heads are situated in
Egypt, Gebel Shendib being a mass of mountains cut through by the
22nd parallel. Collecting from the west face of the mountain group,
a number of drainage lines unite, in the lower hills flanking the
main mass, to form the main channel of Wadi Shendib, which courses
westward through low hill country a little south of the 22nd parallel
to join Wadi Di-ib. None of the heads have been surveyed in detail;
their position is shown on the map from the statements of guides
combined with the knowledge gained by triangulating fourteen of the
principal peaks and sketching the mountain forms from a considerable
distance. As the mountain peaks are of great height (the highest peak
of Shendib, marked by an iron beacon, is 1,912 metres above sea)
and frequently wrapped in clouds for days or even weeks together,
it is probable that the heads of Wadi Shendib are very steep and
convey considerable streams at certain seasons.
=Wadi Hareitra=, which lies just within Egypt, has likewise only been
sketched in from a distance, but having been approached more closely
its course is better known than that of Wadi Shendib. Its main head
is nearly on the frontier, in longitude 36° 20′, between Gebels
Shendib and Hanquf. From its head it makes a nearly quadrantal turn
northward and westward, with a radius of about ten kilometres, among
the mountains from which it receives tributaries, and then crosses
the plain westward, turning south-west among low dark hills to join
Wadi Di-ib after a course of about forty to forty-five kilometres
from its head.
The unnamed drainage channel which is blocked by sand at =O Harbub=
before reaching Wadi Di-ib heads in a tract of low hills with
sandy interspaces about thirteen kilometres west of Gebel Elba;
it receives no part, however, of the drainage of Elba itself, which
goes northward by other more important channels. It is a broad and
shallow ill-defined drainage line across the sandy plain, with very
few trees, but its feeders from the low hill tract of Sul Hamid
are less barren. The principal interest of this drainage line lies
in its forming a convenient direct road from Bir Meheriqa to Bir
Akwamtra and Halaib, being far less sandy, as well as shorter, than
any alternative route round the north side of Sul Hamid. In using
this road, one leaves the drainage line to the south on the plain,
and skirts the hills of Sul Hamid till one reaches the flat sandy
divide at the head of Wadi Eikwan, with the “Scragged hill” of
Qash Amir in view. Here one turns eastward about four kilometres
south of Qash Amir, and follows an easy pass into Wadi Siamtit,
a small feeder of Wadi Yoider, whence tracks lead to Bir Akwamtra,
Bir Kansisrob, and Halaib.
=Wadi el Qurat=, which joins Wadi Di-ib from the west in latitude
22° 8′, is a broad wadi with great abundance of trees. Its main
head, which has not been surveyed in detail, appears to be in Gebel
Shiab, about twenty-four kilometres above its junction with Di-ib,
and the first part of its course is through a rugged tract of low
hills. Before reaching Wadi Di-ib it is joined by the =Wadi Dibir=,
and Wadi Hashimaiyib on the north and by =Wadi Oshqeq= on the
south. The northern feeders are rather complex, owing to numerous
anastomosings and cross-connexions in the low hill country between
Gebel Mashushenai and Adar Aweib; but they contain abundance of
vegetation and give good grazing grounds. The short Wadi Dibir heads
in =Wadi Mashushenai=, part of the drainage of which it captures. Wadi
Mashushenai is a little wadi to the south of Gebel Mashushenai, with
a well, =Bir Mashushenai=, near its head; part of its drainage goes
south to Wadi Dibir as above mentioned, while the rest continues as
Wadi Mashushenai, flowing south-eastward among low hills for about
five kilometres to join Wadi Hashimaiyib.
=Wadi Hashimaiyib= heads between Gebel Warabeit and Gebel
Mashushenai. Curving round the north of Gebel Mashushenai almost in
a semicircle, it runs south-south-east among low hills to join Wadi
el Qurat after a course of about sixteen kilometres. Besides the
Wadi Mashushenai above-mentioned, Hashimaiyib receives, just before
entering el Qurat, the =Wadi Sinqinyeib=, which drains part of the
west face of Adar Aweib and the hills west of it, with a length
along its main channel of ten kilometres. There is an easy road
up this wadi, passing close west of Adar Aweib into Wadi Wieqwer,
a tributary of Wadi Warabeit; there is no actual pass, because the
westward drainage of Adar Aweib actually splits, one part going
north by Wadi Wieqwer, and the other south by Wadi Sinqinyeib.
=Wadi Warabeit= has its most important head at the easy and well
known pass of =Bani Sana=, leading into Wadi Hamida. It is here a
rather wide wadi, with a fairly rapid fall (about thirteen metres per
kilometre), between the high hills of Gebel Hamida and those forming
the south prolongation of Gebel Geror, and receives numerous feeders
from either side. For the first six kilometres, it runs south-east;
it then arrives at a small open space, where it is joined by eastward
drainages from Gebels Hamida and Warabeit, and turns rather sharply
to the east-north-east. After coursing in this direction for some
five kilometres, it enters another open space, where it receives
several feeders, the principal being the =Wadi Wieqwer=, draining
northwards from the hills west of Adar Aweib. It then receives the
=Wadi Kwileimidaiyeib= from the north, and cuts eastward through
the hills to join Wadi Di-ib. The total length of the Wadi Warabeit
from the pass of Bani Sana to Wadi Di-ib is nineteen kilometres,
and in this length it falls from 335 to 113 metres above sea-level,
so that its average slope is nearly twelve metres per kilometre. Both
the wadi itself and its feeders are abundantly supplied with trees
and bushes, while coarse grasses abound in places. Wadi Warabeit
forms a convenient road from Bani Sana to Bir Meheriqa, being free
from sand and well stocked with camel food.
=Wad el Qireira=, which joins Wadi Di-ib from the south-west to
form Wadi el Kiraf, is really only the terminal portion of the more
important Wadis Didaut and Baueiwai, which join to the north-east
of the conspicuous dark hill mass called Ti Keferiai. It is a
broad shallow drainage line across the sandy plain, with little
vegetation. To the north of it, small hills are dotted over the
plain, the most important being one of red granite, called Osnei,
containing a galt which yields water for some time after rain. To the
south are the low hills of Tishushi, partly smothered in drift sand.
=Wadi Didaut=, a feeder of the Wad el Qireira, commences its course
south-west of the hill of Adar Aqdeib. One of its heads leads to the
easy pass of Sarob Kwan, on the road to Bir Meisah. Another leads
to a water source in the hills south of Adar Aqdeib, called =Megwel
Didaut=, while a small feeder a little lower down, coming from Adar
Aqdeib, also contains a water source called =Megwel Adar Aqdeib=. Both
these water sources are within about half an hour’s journey from
the main wadi. After passing Adar Aqdeib, Wadi Didaut curves round
to the north, receiving feeders from the hills of Um Ein and Qara
Saba to the south, then turns east-north-east, passing between the
hills called Kikeiyet Sharqi and Kikeiyet Gharbi, and then between
the red granite hills of Adatalob Adara and the black mass of Ti
Keferiai to join Wad el Qireira. The total length of Wadi Didaut is
about thirty-five kilometres, and its average slope is about eight
metres per kilometre. Its upper parts possess abundance of vegetation,
the beautiful flowering bush called Sarob being conspicuous in Sarob
Kwan; but in its lower portions it becomes almost lost in drift
sand. There is an easy open track from near Megwel Adar Aqdeib,
passing between the high hills called Qara Saba and Gebel Um Ein,
to the Wadi Baueiwai.
=Wadi Baueiwai= heads in the mountains south of Hadal Aweib
Meisah. Numerous feeders from the mountains course across a tract,
about six kilometres in diameter, of very low granite hills called
Iarih Meisah; this tract is almost entirely shut in by mountains
and high hills, with an outlet south-west of Gebel Um Ein. Through
this outlet the main channel passes, and receives the =Wadi Miatit=,
draining the mountains of the same name, from the south-west. Curving
in a great sweep round the foot of Gebel Um Ein, Wadi Baueiwai
turns north-eastward, passing close south-east of the hills of Qara
Saba and Ti Keferiai to join the Wadi Didaut and form the Wad el
Qireira. From the head of Wadi Baueiwai there appears to be an easy
pass by the east side of Hadal Aweib Meisah into the heads of Wadi
Meisah. A small feeder of Wadi Baueiwai, draining the north-east
flanks of Gebel Um Ein, leads to a water source called =Megwel
Um Ein=. Another feeder coming in from the west side of Qara Saba
forms an easy route to Wadi Didaut, as already mentioned above. The
principal other tributaries of Wadi Baueiwai are the Wadis Aqwem
and Hamida. =Wadi Aqwem= is a broad and very sandy wadi coursing
north-north-east along the west side of Gebel Nubitra, and reaching
Wadi Baueiwai in about latitude 22° 18′; it leads to a water source
called =Megwel Aqwem=, situated just south of the end of a long spur
of high hills running out north-eastward from Gebel Miatit. Lower down
its course Wadi Aqwem is fed by tributaries from the high hills east
of it, one of which, the =Wadi Nubitra=, contains a well. This well,
called =Bir Nubitra=, is said to yield only very small supplies;
it is situated about three kilometres up the Wadi Nubitra, among
high hills. One of the many heads of the small Wadi Nubitra leads
northwards by an easy pass into the head of Wadi Hamida.
The =Wadi Hamida= heads in the mountain of the same name, and courses
parallel to Wadi Aqwem, from which it is separated by a long ridge
of high hills. About one and a half kilometres below its head at the
easy pass into Wadi Nubitra above referred to, it receives a small
gully from the east; by following up this gully, which is narrow and
tortuous, for about a kilometre, one can reach a tiny spring called
=Megwel Hamida=. When I visited it in April 1908, the spring was a
mere trickle, very salt; a galt a little further up the gorge was
dry at the same time, but bears signs of holding a useful store of
water after rain. About three kilometres below the gully containing
the spring, Wadi Hamida reaches an opening whence one can either
go south-east for two kilometres to the easy pass of Bani Sana, or
north-west through a gap in the longitudinal ridge which encloses the
wadi on the left. Wadi Hamida itself, however, keeps straight on its
course past Gebel Geror, and joins Wadi Baueiwai south-east of the
hill of Ti-Keferiai. The heads of Wadi Hamida contain a fair amount
of vegetation, but its lower parts are more barren and very sandy.
=Wadi Di-it= drains the north parts of the hill mass of Sul Hamid,
and courses north-east to reach the coast independently about latitude
22° 29′. It has not been explored, and is of no great importance;
vegetation in it is probably confined to its upper parts among the
hills. Of its total course of about thirty-five kilometres, a large
portion lies over the sandy coast-plain.
=Wadi Eikwan= is a broad shallow and sandy channel draining the high
jagged hill called Qash Amir and the eastern parts of the low hill
mass of Sul Hamid. Its head is about four kilometres south of Qash
Amir, in the flat sandy plain. Taking at first a northerly direction
past the west side of Qash Amir, it turns to the north-east further on
and crosses the coast-plain to reach the sea only a little south of
the mouth of Di-it. Its total length is about thirty six kilometres,
and its average slope is about nine metres per kilometre.
=Wadi Yoider=, the next wadi to the east, is of considerable
importance, as it drains the west portion of Gebel Elba and its heads
are extremely rich in trees and other vegetation, while one of its
tributaries contains a large well of good water (Bir Akwamtra). The
main head of Wadi Yoider may be considered to be the wadi which bears
the special name of =Wadi O Sir Hadal=, draining the south-west flanks
of Gebel Elba and the north-west flanks of Gebel Hanquf, and heading
in an easy pass close to the well of =Bir Salalat O Sir=, about 450
metres above sea-level. Wadi O Sir Hadal courses north-west between
the mountain ranges for about eight kilometres, receiving a rather
large feeder from the south about six kilometres below its head. It
then emerges from the mountains and turns north among lower hills,
here receiving the =Wadi Qeirat=, draining westwards from near the
summit of Elba. A few kilometres further on it enters an open plain
sloping rapidly downwards to the north, receiving the small and narrow
=Wadi Siamtit= from between two high hill masses to the west. From
here onwards Wadi Yoider courses in gentle curves a little north of
east to reach the coast in about latitude 22° 27′. A well called
=Bir Nabit=, situated in Wadi Yoider, a few hundred metres up from
its mouth, is believed to yield only brackish water. In its journey to
the coast Wadi Yoider receives several feeders from among the rugged
granite hills of El Sela to the west of it, as well as the important
=Wadi Akwamtra= from the north-east flank of Gebel Elba. The head
of this Wadi Akwamtra is quite close to the summit of Elba, and its
course is at first almost due west, afterwards changing to nearly
north among the lower flanking hills, and dividing into two channels
which re-unite lower down. =Bir Akwamtra=, one of the best water
sources in the Bisharin country, is situated at an altitude of 330
metres above sea-level in the eastern channel of Wadi Akwamtra, about
three kilometres up above the place where it leaves the hills. It is
an excavation in the stony floor of the wadi. The water in April 1908
was about four metres below the wadi floor, and formed a pool about
two metres in diameter in a wide open hollow which filled as fast
as it could be emptied. The water was of excellent quality. There
are two other wells a few hundred metres further down the same wadi;
one of these contained a little water, while the other was dry, and
only the principal well was being used. The floor of the wadi near and
above the well is very stony, so that it is not a very good camping
ground, and the Hamedorab Arabs pitch their tents of matting further
down the wadi. When I visited the place there were numerous Bisharin
Arabs at the well with their women and children, all busily employed
in watering their flocks and herds and washing their clothes. The
wadi, in spite of its stony floor, is literally full of large trees,
principally acacias, so close together that laden camels cannot
pick their way through them for more than a short distance above
the well, and thousands of doves inhabit the trees. There are some
ruins near the wells, built of boulders set in mud; they are said to
have been erected by Dervishes in 1886, when they seized Halaib and
Bir Akwamtra. These Dervishes were killed off by Egyptian troops,
some of them being chased to Bir Meisah and shot there.
As the densely wooded and stony character of Wadi Akwamtra prevents
camels from passing up it much above the well, I found it necessary,
in order to pitch a camp within a reasonable distance of the summit
of Gebel Elba, to descend Wadi Akwamtra for about a kilometre
and to cross the Asut Duk pass leading east into the head of Wadi
Yahameib. This pass is too steep for loaded camels, and even riding
camels have to be led down it; baggage camels have to go round the
hill spurs north of the pass. The head of Wadi Yahameib is also full
of trees and scrub, but it is possible to get camels up within four
kilometres of the summit of Elba by this route, whereas Bir Akwamtra
is over six kilometres from it.
=Wadi Aideib=, with its principal tributary the Wadi Yahameib, drains
the north-east portion of Gebel Elba and reaches the sea in about
latitude 22° 21′. A well, called =Bir Abu Ramad=, is situated in
the wadi bed not far from the sea; like that of almost all the wells
close to the coast, its water is probably brackish. The main head of
Wadi Aideib is on the east side of the main peaks of Elba. Coursing
at first north-eastward, this drainage channel runs through an
open sloping plain about one and a half kilometres wide between
the mountain spurs, its channel here dividing into a great loop
with numerous feeders from the ranges on either side. Passing west
of the high isolated granite mass of Karam Elba, it runs northward
over the sloping plain, receiving the Wadi Yahameib from the west
near the low red granite hills called Ti Hamra, and then courses
north of east to the sea.
=Wadi Yahameib= originates on the north-west flanks of Gebel Elba,
where steep well wooded gorges unite in a steeply sloping stony
plain, covered with trees and scrub, between two great spurs of the
mountain. There is no pass at its main head, but just before it enters
the plain there is a small feeder from among the hills to the west,
by following up which one can get over a rather steep pass called
=Asut Duk=; this pass forms a short cut for unladen camels between
the wells of Kansisrob and Akwamtra, but is too steep for animals
loaded with baggage. Curving round to the east, Wadi Yahameib is fed,
just before it joins Wadi Aideib, by the =Wadis Akau= and =Kansisrob=,
both draining the north parts of a great spur of Gebel Elba. Wadi Akau
contains a small spring, called =Megwel Akau=, a short distance above
its opening from the hills, while Wadi Kansisrob contains a great well
of good water called =Bir Kansisrob=, a short distance up from its
mouth. Bir Kansisrob is second only to Bir Akwamtra in importance,
and there are usually many Bisharin camps in the wadi just below
it. Like all the wadis draining from Elba, Wadis Yahameib and Aideib
are full of trees and scrub and grasses; in going to the foot of Elba
up the head of Wadi Yahameib with baggage camels, much more difficulty
is caused by the closeness of the trees and scrub than by the stony
nature of the floor. The Elba district is, I believe, the only place
in the Eastern Desert of Egypt where vegetable growth is so abundant
as seriously to hinder one’s caravan in approaching the mountains;
for the progress of baggage camels to be arrested while still four
or five kilometres from a peak by the steep and stony nature of the
ground is common enough; but for the arrest to be due to trees and
scrub was a new and interesting experience. Even the sand dunes on
the west side of Wadi Yahameib are half-covered with coarse grasses,
and look green instead of the usual yellow. When we could get no
further with our camping equipment, Mr. Bakewell, who had been in
South Africa, informed me that we were in what would be called in
that country “open bush”; but in comparison with the rest of
the desert the place was a jungle.
=Wadi Todhi= drains the high hills about Karam Elba. In the upper
part of its course it flows north-east between Karam Elba and a
range of lower granite hills called Mikeriba; emerging thence on
to the plain, its drainage spreads out over a tract, called =Karam
Hindi=, covered with trees, whence part drains to the Wadi Aideib
while another part goes to the sea near Suakin el Qadim.
=Suakin el Qadim=, is a collection of mounds close to the sea a little
south of latitude 22° 20′. Bent, who visited the place in 1896,
found “nothing earlier than Cufic remains, unless the graves,
formed of four large blocks of madrepore sunk deep into the ground,
may be looked upon as a more ancient form of sepulture.”[101]
My native assistant reported there was no well at the place, nor
anything of interest besides the graves.
=Wadi Delowa= is a small wadi entering the sea about six kilometres
south-east of Suakin el Qadim. It originates in the low hill country
near Mikeriba and flows north-east between the little red hill of
Alafot and the low banks called Alafot Onqwab on the north and the
granite hills of Kreishim and Taar Ara on the south.
=Wadi Serimtai= is an important drainage line, the main head of
which is situated in the Sudan, probably near the great mountain of
Asotriba. It enters Egypt in longitude 36° 22′, coursing northward
between Gebel Hanquf and Gebel Shendodai, from which last-named
mountain it receives a feeder called =Wadi Um Seyal=. After passing
Gebel Shendodai it crosses a tract of low granite hills to the foot
of Gebel O Sir Eirab, where it receives the wadi of the same name and
numerous feeders from Gebel Hanquf. It then turns north-east, passing
along the foot of the spurs of Elba, and north of the granite hills
of O Wota and Abai Sis to reach the sea ten kilometres north-west of
Halaib. About twenty-five kilometres up from its mouth, Wadi Serimtai
contains a well called =Bir Sararat Serimtai=, which has, however,
not been visited. The =Wadi O Sir Eirab=, an important tributary of
Serimtai, drains the south flanks of Gebel Elba, coursing at first
south-west and then turning sharply eastward. At the turn is a well in
the wadi floor called =Bir Salalat O Sir=, 440 metres above sea-level,
close to which is an easy pass leading into the head of Wadi O
Sir Hadal, a tributary of Wadi Yoider. From its entry into Egypt
to its mouth, Wadi Serimtai has a length of forty-five kilometres,
and an average slope of twelve and a half metres per kilometre. It
contains plenty of trees and scrub, especially in its upper parts.
=Mera Kwan= is a wadi draining north-eastward from Gebel Shendodai
and entering the sea a little north of Halaib. It has not been
surveyed in detail, but as it drains from high mountains it doubtless
contains plenty of vegetation, especially in its upper parts. The
lower half of its course is rather sandy, passing among low hills
on to the coast-plain.
=Halaib=, the only permanent village on the Red Sea coast of Egypt
south of Qoseir,[102] is situated in latitude 22° 13′ 25″ N.,
longitude 36° 38′ 56″ E.[103] The name of the place is pronounced
locally Oleiyib, and though I have retained the established European
spelling as given on the charts, none of the natives would recognise
the name if pronounced in its Europeanised form. Its most conspicuous
buildings, and the only ones composed of masonry in any form, are a
fort and a block-house; there are a few rude wooden shanties, mostly
built of timber which has been cast up on the beach, but the bulk of
the population live in little reed huts and tents of matting. Halaib
is the headquarters of a small police force under the command of a
moawen, the men being lodged in the fort. The fort, which stands about
forty metres from the sea on low ground, is an irregular octagon in
plan, about ten metres in diameter by six and a half metres high. As
its top is only eight metres above the sea and there are low banks
west of it, the fort is not very conspicuous as one approaches it
from the landward side, but being whitewashed and open to the sea
it is a good landmark for sailors in the neighbourhood. It has two
flagstaffs, from which the British and Egyptian flags are flown on
Fridays. The fort is entered by a ladder, the floor forming the
police quarters being about three metres above ground. Below are
water tanks, and above a trap door gives access to the roof, which
is carried on iron rails and plastered over with stucco. The roof
vibrates too much for it to be used as a triangulation station,
and observations here were taken from an eccentric point on the
ground and afterwards reduced to centre. The block-house is a smaller
rectangular structure, whitewashed, situated on a low bank about 400
metres south-west of the fort. A small jetty, built of coral, runs
out from near the fort far enough for a small boat to get alongside.
There are five wells at Halaib, all within a few hundred metres of
the fort. The water is very hard, and exerts a very strongly aperient
action on those unused to it, though the Arabs of the place consider
it very good. A small Government garden near the fort contains a few
small date palms, but there is no other cultivation. There is a sort
of bazaar, where one can buy clothes, sugar, dates, fat, etc., but
the supplies are small and there was no flour to be got when I was
there. Eggs can be purchased from the Arabs, who possess a few fowls,
and excellent fish can be got very cheaply from the fishermen. For
a daily wage of eight piastres a fisherman supplied me with as much
fresh fish daily as I and my men could eat. Sheep can be got from the
hills at a day’s notice, a good fat one costing L.E. 1. Firewood
has to be brought in from the mountains, and any European making
a stay at the place would do well to send to Bir Kansisrob or Bir
Frukit for pure water at the same time. The people are very friendly,
but only a few speak Arabic. There is a _kuttab_ where boys learn
to read and write Arabic under the tuition of a sheikh from Suakin,
so that Arabic may perhaps be more spoken after another generation.
There are two islands a little north of Halaib, both low and
sandy. The larger one, called =Geziret Halaib el Kebir=, is nearly
triangular, with sides about three and a half kilometres long. It
can be reached easily by wading across a narrow channel in low
states of the sea. On it is the grave, marked by a wooden cross, of
Lieut. Stewart, R.N., who lost his life in a fight with Dervishes
here in 1886. The smaller island lies further north; it is called
=Geziret Kwolala=[104] on account of its nearly circular shape.
Halaib possesses an excellent harbour, though it is sometimes
difficult of access to sailing vessels owing to the direction of its
entrance.[105] It is visited occasionally by Coast Guard cruisers as
well as by small trading boats from Suakin. On enquiry of the local
sailors, I found most of the names given on the Admiralty Charts
of this district to be unknown to them. For example, Abu Dara,
Sherm Alueda, Ras Abu Fatma, Elba Island, Ras Jazriyal, and Cape
Elba were all unknown. Abu Dara was called by the natives Shekra
el Delam, while Elba Island was called Geziret el Dibia, and Cape
Elba is locally known as Ras Hadarba. I obtained the following names
for the small anchorages north and south of Halaib, though I could
not locate them exactly on the maps, as the sailors could not read
a map sufficiently well, and the harbours themselves are mere gaps
through the outer coral reef, not visible indentations of the actual
coast-line. Starting from Bir Adal Deib and going southward, Mersa
Abu el Qâsim is near the mouth of Wadi el Kiraf; a big tree forms a
landmark for entering it. Further on is Mersa Harâba, then Mersa Abu
Naam with an island opposite to it, then, after passing Ras Unbilat,
comes Mersa Yoider, at the mouth of Wadi Yoider, where there is a
well called Bir Nabit. Passing Abu Ramad well in Wadi Aideib, and
Suakin el Qadim, one comes to Mersa Aqwetit, then to Mersa Serimtai,
at the mouth of Wadi Serimtai, opposite the island of Kwolala, and
then to Mersa Halaib itself. South of Halaib the principal anchorage
is Mersa Shellal, at the mouth of Wadi Shellal. The cape in latitude
22° 10′ is called Ras Qubet Isa. A small anchorage south of Ras
Hadarba (Cape Elba) appears to be called indifferently Mersa Hadarba
(from the hills near it) or Mersa Qabatit (from the wadi and well
near it); but I could not make quite sure if these are one and the
same, or two separate anchorages.
=Wadi Shellal= heads between the high mountain masses of Gebels
Shendodai and Shellal, and courses north-east for about thirty
kilometres to reach the coast about four kilometres south-east of
Halaib. In its lower part, where it crosses the coast-plain, it is
a broad shallow drainage channel full of scrub. Its upper parts,
which have not been explored, are doubtless well supplied with trees,
and are stated to be the principal habitat of the Hamedorab Arabs.
=Wadi Aqilhoq=, which drains the eastern parts of Gebel Shellal,
courses about parallel to Wadi Shellal a few kilometres further
south. It contains a well, =Bir Frukit=, about twenty kilometres up
from its mouth, near some dark conspicuous foot hills called Gebel
Balatitda. This well yields a constant supply of very good water,
and is the place where I sent for my water supplies in commencing my
return march to Port Sudan. The position of the well as shown on the
map is only approximate, but its direction having been pointed out
with the alidade by guides from two plane-table stations, I believe
the location is pretty nearly correct.
=Wadi Aqwei= drains east of north from among the foot-hills east
of Gebel Shellal, and enters the sea four kilometres west of Ras
Qubet Isa. Where I crossed it two kilometres from its mouth it was
a broad shallow wadi with plenty of scrub, dividing round a low but
conspicuous gravel bank before reaching the sea.
=Kreit-reit-or= is a similar wadi to that last mentioned, coursing
north-eastward over the plain from among low hills, and entering the
sea five kilometres south-east of Ras Qubet Isa. About two kilometres
south of Kreit-reit-or, at a distance of three and a half kilometres
from the coast, and thirty metres above sea-level, are the bitter
wells of =Ti Kureitra=. These are four wells, sunk about twelve metres
deep in the gypseous strata which here underlie the sand and gravel
of the coast-plain. The wells are lined with slabs of selenite. The
water is so strongly purgative that a number of my Arabs who drank
of it were made extremely unwell, and the wells are chiefly used for
watering the flocks of sheep which graze in the neighbouring valleys.
From the group of conspicuous though not very high hills called Gebel
Hadarba, ten kilometres west of Ras Hadarba (Cape Elba) many drainage
channels cross the coast-plain towards the sea in a direction north
of east. Some of the drainage lines form the north side of the hills
reach the sea east of Ti Kureitra wells; but others lose themselves in
a quicksand called =Kuatianai=, or “the devourer,” which covers
a large triangular space of about twenty square kilometres about the
cape. At the actual cape, rocks are visible at the coast, and the
quicksand, so far as I could judge from a distance, appears to be
really a lagoon, filled with the sand washed down from the hills. The
Arabs state that camels wandering on this sand get swallowed up; the
colour of its surface is distinctly darker than the rest of the plain.
On either side of the 22nd parallel, near the sea are low
gravel-covered banks of calcareous grit, seventy metres high in
places, and through these pass several broad wadis draining from
the low hill country further west. The chief of these wadis, called
=Wadi Qabatit=, enters the sea at a well defined inlet of the coast
called Mersa Qabatit. A well, =Bir Qabatit=, is situated in the bed
of another drainage channel a little south of the main wadi, one
and a half kilometres south-east of the mersa and 3·85 kilometres
south of the 22nd parallel. The ground at the well is only five
metres above the sea. The well is a big excavation in the wadi floor,
and its water surface is about at sea-level. To me the water tasted
decidedly salt, but the Arabs say it does not purge them.
* * * * *
[Footnote 89: Floyer’s map (_Geog. Journal_, 1893) gives the name
Gemal as continuing further up as far as the pass into Wadi Durunkat;
but my guides say this is an error.]
[Footnote 90: This road is said to lead _via_ Ghuel, Um Khariga,
and Dabur, to Gebel Hamrat Wogud.]
[Footnote 91: For a brief mention of the ruins of Berenice, _see_
p. 29.]
[Footnote 92: Each of the three vowels in Naait is pronounced broad
and separately, so that the word has three syllables.]
[Footnote 93: _Allawi_ = crooked.]
[Footnote 94: I did not hear anything of this in 1907 when in the
neighbourhood, perhaps owing to the ignorance of my Ababda guides. The
information was given me further south in 1908 by several Bisharin
guides, who appeared to know the place well and who all agreed on
the point.]
[Footnote 95: The authors of “The Anglo-Egyptian Sudan,” 1905
(Vol. I, p. 87) erroneously place Bir Shalatein in Wadi Hasium
instead of at the mouth of Wadi Hodein. The mistake has led to
erroneous delineation of the administrative boundary between Egypt
and the Sudan in existing maps (_see_ p. 74).]
[Footnote 96: This and the other main feeders of Wadi Hodein are
described in more detail in following pages.]
[Footnote 97: The final syllable in _Silsila_ is hardly heard when
the name is spoken by an Ababda Arab; it sounds like _Silsi_ unless
one is listening specially for the end of the word.]
[Footnote 98: To be distinguished from the Wadi Gemal further north
mentioned on p. 100.]
[Footnote 99: Bir Madi, 12¼ kilometres north of Bir Sararat Seyet,
was at this time open and giving good supplies.]
[Footnote 100: This and the other main Egyptian tributaries of Di-ib
are described in more detail in the following pages.]
[Footnote 101: _Geographical Journal_, 1896.]
[Footnote 102: Qoseir is in latitude 26° 6′ north, about 400
kilometres as the crow flies from Halaib.]
[Footnote 103: The position given is that of the centre of the fort,
as determined by my triangulation from the Nile Valley.]
[Footnote 104: _Kwolala_ is the Bishari word for circle.]
[Footnote 105: _Red Sea Pilot._ 1900. p. 130.]
CHAPTER VI.
* * * * *
=THE MOUNTAINS AND HILLS.=
* * * * *
It has been already mentioned (p. 19) that the principal mountain
masses are divisible into ten main groups as follows:—
i. The Migif — Hafafit — Nugrus — Hangalia — Zabara group;
ii. The Abu Hamamid — Hamata — Abu Gurdi group;
iii. The Um Gunud — Dahanib — Batoga group;
iv. The Abu Dahr — Orga — Um Tenebda group;
v. The Faraid group;
vi. The Awamtib — Abraq — Dif — Aqab el Negum — Mishbih group;
vii. The Gerf — Korabkansi — Abu Hodeid group;
viii. The Meisah — Adar Qaqa — Is group;
ix. The mountains of the Alaqi basin west of Gebel Adar Qaqa;
x. The Elba — Shendib group;
while there are numerous more or less isolated mountains and hills
lying outside these principal masses. In the present chapter a more
detailed account will be given of each of the main groups, taking
them in order from north to south, the principal outlying hill-masses
being considered along with the mountain group to which they are
in greatest proximity. It may be remarked that the geographical
positions of all the principal peaks are tabulated in Chapter III.
=The Migif — Hafafit — Nugrus — Hangalia — Zabara Group.=
The highest mountains of the group (_see_ the detailed map on Plate
VI) form a close cluster, round Gebel Nugrus (1,505 metres) as a
centre, between latitudes 24° 40′ and 24° 55′, while other
more or less detached masses are scattered to the north and west. A
striking feature of the central cluster is the tendency to extension
in a north-west and south-east direction, which is specially marked
in the Hafafit and Hangalia ranges.
=Gebel Nugrus=, the central and highest mountain of this northerly
group, is a great boss of red granite rising to a height of 1,505
metres among schists and gneisses. It is an almost isolated mass,
for though the Hangalia and Hafafit ranges close in on it from either
side, there are passes both east and west of it by which a circuit of
the mountain can be made. In plan, it is a pear-shaped mass, about
fourteen kilometres in length by six kilometres in width, having
its long axis north-west and south-east. Gebel Nugrus is on the main
watershed; its north parts are drained Nilewards by the Wadi Hangalia
and other feeders of Wadi Gerf, while the drainage from its south
portion passes by the Wadi Nugrus and Wadai el Nom to the Wadi Gemal
and thence to the sea. The ascent of the mountain was made from a
camp about four kilometres west of the summit, at the top of the pass
leading into the stony head of Wadi Nugrus. The divide here is flat
and sandy, at an altitude of 691 metres above sea-level, so that the
ascent from camp to summit was 814 metres. Striking eastwards over
the lower ridges which flank the main back-bone of the mountain,
the summit was reached after a climb of nearly four hours. When
ascended from this side, there appear to be two main peaks, of which
the further one, marked by a beacon, is the triangulation point;
the best way up is between the two peaks, as the passage from one
to the other is very rough and steep. Though tiring, the climb is
not very difficult. The top of the mountain (_see_ Plate VII) is a
mass of great rounded knobs of granite, on which a suitable place
for setting up instruments was only found after some searching. The
beacon, in latitude 24° 48′ 34″, longitude 34° 35′ 47″,
is on a rounded eminence not large enough to receive an instrument,
so that eccentric observations were necessary; the distance between
the eccentric point of observation and the beacon had to be found by
a subtense method, as the roughness of the mountain top rendered any
process of chaining or taping impossible. The view from the summit
is very fine. To the west, one sees the pinnacles of Migif and the
nearer long range of Hafafit; to the north-east is the black cone of
Atut; northward, seen over a sea of hills, is Igli; to the east is
the high ridge of Hangalia, culminating to the south in Gebel Zabara.
The sea is visible to the north-east and east, but the sea horizon
was obscured during the three days I spent on the summit by banks of
clouds. These cloud banks simulated the sea horizon very closely,
their upper surface appearing perfectly horizontal. They caused
a peculiar phenomenon at sunrise, producing the optical effect of
two suns rising one after the other owing to the refraction through
the cloud. The first thing seen was a blood-red image of the sun
rising over the true sea horizon, which was only thus discovered,
the sun being seen through the cloud; about three minutes later,
when a little more than half the blood-red disc had risen, the true
sun rays flashed out from another and much brighter segment appearing
over the top of the cloud, so that parts of two sun disks were seen
at once, quite separately, one over the other.
Before descending from the mountain, I went along the ridge south-east
and north-west of the highest point to get plane-table stations; in
either direction progress along the top is extremely difficult. To the
north-west it appeared as though the way would be easier by keeping
on the east side of the ridge, but in reality this was not so, as the
slope was so steep and smooth that some stretches could only be got
over by wriggling along with as much as possible of one’s body in
contact with the rock. The descent from the north-west end of the
ridge to camp was difficult and rather dangerous in places. It is
possible that a better way up the mountain could be found from the
pass at the head of Wadi Hangalia, on the opposite side to where I
started; that pass is 120 metres higher than the west one, so that
the total climb would be lessened by that amount, and the horizontal
distance is about the same.
=Gebel Hafafit= is a very long range, chiefly of gneiss, running in
a nearly straight line south-eastward for over thirty kilometres. Its
highest peaks are at its north end, where they are not very much lower
than those of Gebel Nugrus; the heights decrease gradually further
south. Half way down the range is a very conspicuous peak called
=Um Moghar=, 860 metres above sea, while another well marked summit,
the only one which I climbed, exists near the south end and rises to
744 metres. This last-named point is marked by a beacon, in latitude
24° 35′ 32″, longitude 34° 45′ 22″. On either side of the
main back-bone of Hafafit are high flanking ridges. The drainage of
Hafafit practically all flows seaward by the Wadi Gemal; the west
faces are drained by Wadi Hafafit, and the east ones by Wadi Nugrus.
East of the south part of Gebel Hafafit are some remarkable bosses
of granite, of which the chief, Gebel Abu Had, rises to 633 metres
above sea, and is a landmark for Bir Abu Had. Another remarkable hill,
closer in to Hafafit and the Wadi Gemal, is shaped like a bell with a
handle on the top; this hill, which forms a good landmark, is called
=Gebel Um Regeba=, and its summit is 571 metres above the sea.
PLATE VII.
[Illustration: Summit of Gebel Nugrus. (Granite).]
[Illustration: Summit of Gebel Abu Hamamid. (Schists).]
=Gebel Migif= is a very spiky gneiss mass situated about thirteen
kilometres west of Gebel Nugrus. It has several summits of about
equal height, fairly close together, but separated by deep clefts. The
triangulation beacon is on the western peak, in latitude 24° 47′
23″, longitude 34° 27′ 30″, 1,199 metres above sea-level. The
foliation planes of the rock dip to the north, and the only safe
means of ascent is up the resulting north slopes. The south aspect
is precipitous. When ascending the mountain, I pitched my camp 2·7
kilometres north of the beacon, in a gully draining into Wadi Shait,
west of another gully containing the water holes called Galt Um
Karaba, at an altitude of 607 metres above sea-level. The ascent, of
592 metres, took two hours steady climbing, and was not difficult. I
kept on the west side of the gorge till near the top, and this is
the best way up the mountain, for I found the gorge itself to be
steep and abounding in impassable precipices. The view from Gebel
Migif is shut in to the east by the high masses of Gebels Hafafit
and Nugrus; Gebels Atut and Igli are conspicuous to the north;
to the south-east, one overlooks the great sandy basin of Wadi
Hafafit; while to the south-west is more open country in which the
two remarkable cones of El Nahud, the sharp peak of Gebel Abu Khrug,
the ridge of Gebel Hamrat Selma, and closer in the ranges called Gebel
Dweig, are striking features. On a clear day, the huge mountains of
Hamata and Abu Hamamid, eighty kilometres to the south-south-east,
can be discerned. The photographs on Plate VIII will give an idea of
the views looking towards Gebels Nugrus and Dweig respectively. In
the upper view Gebel Nugrus is seen behind the Hafafit range; in the
lower, the masses close in are Gebel Dweig, while in the distance,
to the right of the centre, is Gebel Hamrat Selma, and behind it on
the horizon the spike of Gebel Abu Khrug. The precipitous nature of
the south side of Gebel Migif is evident in both views.
The north and west sides of Gebel Migif are drained by the Wadi
Shait, which passes the foot of the mountain; the steep south face
drains into Wadi Dweig, a tributary of Shait; while the eastern face,
flanked by low hills, is drained by Wadi Hafafit.
Gebel Dweig is a small group of high hills close to the south of
Gebel Migif, with which it combines to form a _cul-de-sac_ round the
head of Wadi Dweig. Gebel Dweig resembles Gebel Migif in character,
except that it is lower; the hill on the south side of the narrow
opening by which Wadi Dweig leaves the _cul-de-sac_ is 864 metres
above sea, and this is believed to be the highest of the group. The
eastern part of the mass is a curiously curved range sweeping round
nearly in a semicircle.
=Gebel Hamrat Selma= is a high ridge rising from the plain about
fifteen kilometres south-west of Gebel Migif. I did not approach it
closely, but fixed the position of its highest point, which is 761
metres above sea-level, by triangulation.
=El Nahud= (the breasts) is the name given to two very remarkable
conical hills of volcanic rock rising from the plain on the north
side of Wadi Natash to the south of Gebel Hamrat Selma. The two
hills are about five kilometres apart, one being south-east of the
other. The north-eastern cone is the sharper of the two, but they
have both the same altitude of 662 metres above the sea and rise
about 130 metres above the surrounding country.
=Gebel Abu Khrug= is a granite hill-mass with a remarkably sharp high
peak, about twenty-five kilometres south-west of Gebel Migif. The
summit, which is surmounted by a triangulation beacon, in latitude
24° 38′ 57″, longitude 34° 16′ 19″, has an altitude of 870
metres above sea-level. Abu Khrug, from its striking Matterhorn-like
shape and its situation in fairly open country, is a conspicuous
landmark for great distances. The Arabs who were sent to erect the
beacon stated that the ascent was very difficult.
=Gebel Sufra= is a mass of rather flat-topped high hills, partly of
volcanic origin, about eighteen kilometres west of Abu Khrug, on the
north side of Wadi Shait. The triangulation beacon on the summit is in
latitude 24° 38′ 42″, longitude 34° 4′ 13″, at a height of
690 metres above sea-level, and 340 metres above the well of Um Gubur,
which is in the Wadi Shait about three kilometres to the south-east.
=Gebels Nazla= and =Um Serg= are moderately high hills lying to
the south of Gebels Sufra and Abu Khrug, between the Wadis Shait
and Natash.
=Gorf el Natash= is a syenite hill on the south side of Wadi Natash,
about five kilometres south-west of Bir Masur, while =Gebels Muktil=
(470 metres), =Derera=, and =Um Goraf=, are prominent hills lying
still further south near Wadi Antar.
PLATE VIII.
[Illustration: View from Gebel Migif, looking east, showing the
Hafafit and Nugrus Ranges.]
[Illustration: View from Gebel Migif, looking south-west, showing
Gebel and Wadi Dweig.]
=Gebel Ras Shait= is a group of high rugged-looking reddish hills,
probably of granite, at the head of Wadi Shait, near Gebels Nugrus
and Migif. Its highest peak rises to 1,019 metres above sea. The west
face drains directly into Shait, while the eastern and northern slopes
drain into Wadi Gerf, which joins Shait far to the south-west. Between
Gebels Migif and Ras Shait is a small range of hills dividing Wadi
Shait from the head of Wadi Hafafit; across the south end of this
range, which is composed of dark schists with white granite at its
western foot, there runs a zigzag pass, fairly easy for camels,
to the head of Wadi Nugrus.
=Gebel Mudergeg= is a high range of reddish hills, which with Gebels
Ras Shait and Migif encloses the heads of Wadi Shait. Its highest
point is 1,086 metres above sea. To the east of it are several other
lower ranges, some of white and others of black aspect, which have
not been approached closely.
=Gebel Hangalia= is a great mountain ridge running south-south-east
for about twelve kilometres, from Gebel Ghuel to Gebel Zabara,
consisting chiefly of schists. Its highest peak is 1,241 metres above
sea-level. Its western faces are drained partly to the Nile by the
Wadi Hangalia (a tributary of Wadi Gerf) and partly to the sea by
the Wadai el Nom (a tributary of Wadi Nugrus); its eastern faces,
which are flanked by high ridges, drain into the various feeders of
Wadi Ghadir.
=Gebel Zabara=, a mountain mass rising to 1,361 metres above
sea-level, forms a southward extension of the Hangalia range. The
cairn on its summit is in latitude 24° 45′ 21″, longitude 34°
41′ 53″. The mountain is drained on the north and east sides
by feeders of the Wadi Ghadir, while its western flanks are partly
drained by the Wadai el Nom. Gebel Zabara is chiefly composed of
schists of various types. The ancient emerald mines of Zabara are in
the north-east part of the mountain, about two and a half kilometres
from its summit. A triangulation beacon marks the highest point of the
mountain, but this was only used as an intersection point. I ascended
some of the flanking ridges near the old mines; these consisted of
splintery schists, and though the climbing is steep and rough (_see_
Plate IX), the schists give a good foothold so that the ascent to the
top is probably not very difficult. The ruins in the Wadi Zabara, near
the old mines, are at 514 metres above sea-level; the climb from them
to the summit is thus one of 857 metres. Due south of Gebel Zabara
is a high ridge, the north-west end of which is 1,104 metres above
sea-level; this ridge is the most conspicuous of a mass of high hills
flanking Gebel Zabara to the south, which have not been seen except
from a distance, but which are probably drained by the Wadi Nugrus.
=Gebel Ghuel=, which forms a northward extension of Gebel Hangalia,
is likewise composed of schists. Its highest point, the south end
of a conspicuous high ridge, is 1,104 metres above sea. Its eastern
faces are drained by the Wadis Ghuel and Fegas, both tributaries
of Wadi Ghadir, while its western flanks drain into the heads of
Wadi Um Khariga. High hills flank the main ridge on both sides,
especially the east, and through these the drainage channels form
deep gloomy gorges. Wadi Ghuel contains important water holes.
=Gebel Um Khariga= is the name given to several high hill ranges
on either side of the Wadi Um Khariga. Two of these ranges, one on
either side of the upper part of the wadi, form like Gebel Ghuel north
extensions of the high ridge of Hangalia; the western range can be
crossed at a gap by an easy pass, 773 metres above sea-level, which
separates the heads of Wadi Gerf from those of Wadi Um Khariga. These
two ranges shut in the wadi on either side for some ten kilometres
of its northward course, beyond which the country becomes more open
and the wadi curves round to the north-east, passing the north end
of a third range of high hills which is likewise called Gebel Um
Khariga. This third range extends northward for about ten kilometres
from Gebel Ghuel, from which it is separated by a pass forming a good
road over the head of Wadi Ghadir. Its most conspicuous feature is
a twin peak at its north end, 674 metres above sea-level. The main
ridge is flanked by high hills, especially on the east side. Only the
north and west flanks of this range are drained by Wadi Um Khariga,
the eastern side being cut up by feeders of Wadi Sukari. Besides
the pass separating it from Gebel Ghuel, there are two other passes,
one round its north end into Wadi Sukari, and another at its south
end between Wadi Ghadir and Wadi Sukari, so that a complete circuit
of this range can be made by camels. Some of the hills composing
the mass consist of highly magnetic schists, and compass readings
in the region may be disturbed by many degrees.
PLATE IX.
[Illustration: Descending Gebel Zabara. (Schists).]
=Gebel Igli el Iswid= is a rather rugged mountain mass rising among
a sea of lower hills, thirty kilometres north of Gebel Nugrus. Its
highest point, marked by a triangulation beacon, in latitude 25° 4′
6″, longitude 34° 36′ 16″, is 975 metres above sea-level. The
mountain forms a tripartite watershed between the basins of Wadi
Um Khariga (draining the south slopes), Wadi Dabur (draining the
north and west slopes), and Wadi Igli (draining the eastern face),
each of which three wadis courses separately to the sea. In occupying
the triangulation station on the summit, I placed my camp in a gully
draining to Wadi Um Khariga, about two kilometres south-south-west of
the summit at an altitude of 605 metres above sea. The climb of 370
metres to the top from this camp was not difficult, and occupied only
a little over an hour and a half. The mountain consists of very hard
grey siliceous rocks, which ring under the hammer, and are probably
crushed and devitrified felsites (_see_ p. 281). There are galts in
some of the gullies draining from this mountain, hence it is sometimes
called _Igli el Rayani_. At the time of my visit (December 1905)
there was said to be a little water in a galt on the west side of the
mass; but the rock basins in the gully which I ascended were empty.
=Gebel Igli el Ahmar=, sometimes called _El Atshani_, is a lower
hill mass of granite some ten kilometres north-east of Igli el Iswid.
=Gebel Atut= is a high black conical hill thirty kilometres north-west
of Gebel Nugrus. Rising considerably above the hills which immediately
surround it, Atut is visible from a great distance from the west,
and its conical form renders it easy of recognition. Its summit,
marked by a beacon, in latitude 25° 0′ 56″, longitude 34°
23′ 49″, is 908 metres above sea-level and 300 metres above
the branches of the Rod el Atut which encircle its base. A camp can
be placed close to the foot of the cone, and the ascent is easily
made in about an hour. The rock of Gebel Atut is olivine gabbro
(_see_ p. 302), of great hardness, and the whole surface of the
mountain is formed of great blocks, rounded and boulder-like below,
but angular higher up. The blocks have rusty-looking surfaces, but
are perfectly sound rock inside, and they ring like bells under the
hammer. The upper illustration on Plate X shows a view of the summit
of Gebel Atut, from which its blocky nature will be evident. The
view from Gebel Atut is a very extensive one. To the west and north
(_see_ the lower illustration on Plate X) one can see the peaks of
Gebels Muelih, Haggar Dungash, Iteima, Abu Diab, and Hamrat Wogud;
to the south-east are the masses of Migif and Nugrus, while eastward
one looks over a great expanse of hills towards Gebels Dabur and Um
Khariga, with the sea beyond.
The hills of =Um el Huetat=, the highest of which rise over 200 metres
above the wadis round them, are situated about eight kilometres due
west of Gebel Atut; they are composed of schists of various types,
and contain some old mines, mostly in talc schist. They are drained
by the Rod el Farag, a tributary of Wadi Gerf.
On the other side of the Rod el Farag, _i.e._, further west of Gebel
Atut, are numerous scattered hills, the higher of which bear the
names of =Hamrat Mastura=, =El Hamra=, and =Um Himar=. These are of
granite, gneiss, and schists, with some coarse gabbro and numerous
quartz veins.
Still further west is the remarkable ridge called =Erf el Fahid=,
a great quartz vein ten metres wide and two kilometres long, rising
nearly one hundred metres above the Wadi Muelih. A beacon on its
highest point, 579 metres above sea-level, marks the triangulation
station, its position being latitude 25° 0′ 5″, longitude 34°
11′ 52″. South-east of Erf el Fahid is a line of similar but
smaller ridges, also formed of great quartz veins rising through
diorites and schists. Still further down the Wadi Muelih is a curious
horse-shoe-shaped hill of aplite, called =Marwot Rod el Ligaia=,
round which the hills of crushed diorite are penetrated with a
network of quartz veins running in various directions.
=Gebel Muelih= is a great boss of white granite situated close to the
north side of Wadi Muelih in longitude 34°. Its summit, marked by
a beacon, in latitude 24° 52′ 44″, longitude 34° 0′ 37″,
is 707 metres above sea and 350 metres above the wadi which courses
round its south flank, and from which it is easily climbed. The
upper view on Plate XI gives an idea of its appearance as seen from
the base line camp in the wadi six kilometres east of it.
=Gebel Hagar Dungash= is a great mass of high hills situated north of
Gebel Muelih. The beacon on its highest point, in latitude 24° 59′
12″, longitude 34° 2′ 33″, is 815 metres above sea-level. In
the hills which flank the main mass are numerous sharp peaks, one of
the most conspicuous of which, eight and a half kilometres south-west
of the beacon, is called =Gebel Um Dalalil=. A ridge five kilometres
due east of the beacon bears the name of =Erf Rod Um Rashid=. The
rocks of Haggar Dungash are chiefly dark schists.
PLATE X.
[Illustration: Summit of Gebel Atut.]
[Illustration: View from Gebel Atut, looking north-west, showing
Gebels Abu Diab and Hamrat Wogud in the distance.]
PLATE XI.
[Illustration: View in Wadi Muelih (Base-line Camp). Gebel Muelih
in the Distance.]
[Illustration: Granite-boss of Gebel Selaia.]
=Gebel Iteima= is a group of high granite hills rising from the
plain fifteen kilometres north of Erf el Fahid. Its highest peak is
849 metres above the sea. It is drained southwards by the Wadi Muelih.
=Gebel Hamrat Wogud=, which is likewise of granite, is a higher
mountain mass fifteen kilometres east of Iteima. Its highest point,
marked by a beacon, is in latitude 25° 9′ 34″, longitude 34°
20′ 0″, and 1,103 metres above sea. It is drained southwards by
the Rod Um el Farag, a tributary of Wadi Gerf.
Between Gebels Muelih and Mudergeg is a sandy plain with low hills,
the more conspicuous of which bear special names; among them are
=Marwot Rod el Ligah=, =Erf Sagur=, and =Khusa el Faraon=, the
last-named being a group of small but very remarkable black hills
eleven kilometres due south of Erf el Fahid. Marwot Rod el Ligah is
a triangulation point; its beacon is 514 metres above sea-level.
=Gebel Sukari= is a very craggy high ridge of granitic rock
twenty-two kilometres north of Gebel Zabara. Its highest point,
which is at its north end, is 630 metres above sea-level, but the
triangulation beacon was erected on a lower part of the ridge further
south, in latitude 24° 56′ 50″, longitude 34° 42′ 50″,
at an altitude of 476 metres, in order to be near to the extensive
old mines and ruins which exist in the locality. Gebel Sukari is
drained by various feeders of Wadi Sukari.
=Kurdeman= is the name of a low hilly district on the east side
of Wadi Ghadir, thirteen kilometres north of Gebel Zabara. It is
interesting as containing some ancient mines, doubtless worked for
gold. A triangulation beacon has been erected on a hill just above the
workings, in latitude 24° 52′ 35″, longitude 34° 41′ 35″,
at an altitude of 526 metres above sea, or about fifty metres above
the wadi.
=Gebel Sabahia= is a craggy felsite hill five kilometres south-east
of Kurdeman, rising to 520 metres above sea, or about ninety metres
above the wadi. It is drained by the Wadi Sabahia, a tributary of
Wadi Ghadir. In the heads of the Wadi Sabahia, north-east of the hill,
are some old gold mines.
=Gebel Um Tundeba= is a high granite hill near the head of Wadi Um
Tundeba. Its summit is 550 metres above the sea. It forms a landmark
for the water hole called Galt Um Tundeba, which is situated in a
small gully, three kilometres west of the summit of the hill.
=Gebel Amba-ut=, seven kilometres south of the foregoing, is likewise
believed to be of granite; the southern hill of this group is of a red
colour and very conspicuous as one passes from Um Tundeba to Ghadir.
=Gebel Ghadir=, the summit of which, in latitude 24° 50′ 9″,
longitude 34° 47′ 22″, and 636 metres above sea, is marked
by a triangulation beacon, is thirteen kilometres north-east of
Gebel Zabara. I ascended it from a camp 424 metres above sea-level
in one of the gullies draining westward to Wadi Ghadir. The ascent
is easy. The rocks are greenish serpentines and ophicalcites below,
with a white quartz felsite above.
=Gebel Allawi=, situated on the south side of the Wadi Allawi, is a
diorite hill rising to 515 metres above sea. It is best approached
by ascending a small feeder of Wadi Allawi, in which a camp can be
placed within a kilometre of the summit and 160 metres below it. There
are some interesting old gold mines in the quartz veins just below
the beacon on the summit of the hill, and a band of graphitic schist
crops out near the north foot of the hill. The position of the beacon
is latitude 24° 46′ 42″, longitude 34° 49′ 39″.
=Gebel Lewewi= is a dark craggy hill range eight kilometres
east-south-east of Gebel Zabara, between Wadi Allawi and its tributary
Wadi Lewewi. Its highest point, marked by a cairn, is 654 metres
above sea-level. There are some old mines in the lower hills two
and half kilometres south-east of Gebel Lewewi, and others a little
further off in the same direction.
=Gebel Sikait= is a rugged ridge of schists and serpentine situated
in the midst of hilly country fourteen kilometres south-east of
Gebel Zabara. The triangulation beacon which marks its summit is
in latitude 24° 39′ 55″, longitude 34° 48′ 5″, and 771
metres above sea-level, and 330 metres above the wadi which skirts its
western foot. Gebel Sikait is of interest from the abundant ruins and
old emerald mines which exist near it, as well as from the variety
of minerals present in its rocks. It is the Sicily of the Eastern
Desert. Beryl, tourmaline, actinolite, various micas, chlorite, talc
and crystals of calcite are amongst the commoner minerals found. The
serpentine which abounds in its upper parts is highly magnetic, and
the compass was found to be disturbed by no less than 40° near the
triangulation point. Gebel Sikait is drained from the west by the Wadi
Sikait, a tributary of Wadi Nugrus, and from the east by the Wadi Um
Gamil. The best place to climb it from is the Wadi Sikait, and the
ascent, not a difficult one, is rendered interesting by the ruins
and old mines encountered; part of the way one passes over an ancient
made road, now broken in many places by the downwash from the hill.
=Gebel Ras Um Gamil= and =Gebel Um Gamil= are two high hill ranges
south-east of Sikait, which have only been sketched from a distance.
=Madaret Um Gamil= is a conspicuous double-topped hill on the north
side of the Wadi Gemal, seventeen kilometres south-east of Sikait. The
beacon which marks its highest point is in latitude 24° 34′ 52″,
longitude 34° 56′ 28″, and 454 metres above sea. It is best
ascended by a very winding tributary of the Wadi Gemal; this gully,
up which there is a road, leads past the south-west foot of the
hill, and the climb is only one of some 200 metres. The rocks round
Madaret Um Gamil are mostly schists, but the top of the hill is a
hard gabbro like that of Gebel Atut, weathered into rusty looking
blocks. A good view seawards is obtained from the summit, some very
red granite forming a conspicuous feature in the low hills between
it and the coast.
=The Abu Hamamid — Hamata — Abu Gurdi Group.=
This group of mountains is remarkable both for its extent and for
the loftiness of many of its peaks, some of which are among the
highest in Egypt. It is a mass of rugged ridges and peaks, covering
about a quarter of a square degree of the earth’s surface between
latitudes 24° 0′ and 24° 30′, in which the two dominant summits,
Abu Hamamid (1,747 metres) and Hamata (1,978 metres) are the most
conspicuous features in the west and east portions respectively,
while Abu Gurdi (1,562 metres) forms the great terminal peak of a
south-easterly extension of the mass. Plate XII shows two typical
views in this rugged region.
=Gebel Abu Hamamid= is a great ridge of hard greenish schists towering
above the surrounding mountains to a height of 1,747 metres above
sea. Its crest is broken into a number of separate summits, which
appear from most aspects of almost a sugar loaf form; the beacon
is on the most northerly and highest of these, its position being
latitude 24° 14′ 41″, longitude 34° 47′ 38″. The mountain
is best ascended from the Wadi Um Semiuki, a tributary of Huluz,
which drains its north-east face. By ascending this wadi till camels
could go no higher owing to its increasingly rough and stony floor,
I was able to pitch a camp at 865 metres above sea-level and two and
a quarter kilometres north-east of the summit, leaving an ascent of
882 metres to be made on foot. The ascent, which occupied four hours,
was free from difficulty till within about one hundred metres of the
top, but the last portion was extremely steep and was only negotiated
with considerable trouble; it represents pretty nearly the limit of
possibility in getting instruments up difficult places. Once the top
was reached, however, the magnificence of the view obtainable, and the
excellence of the point as a station for triangulating the principal
peaks among the thousands visible, seemed an ample recompense for the
trouble of reaching it. The top of the ridge (_see_ Plate VII, p. 166)
is very rough and narrow, only a little over a metre wide, and it is
difficult to find a spot near the summit where one can spread one’s
blankets for the night with even a slight approach to comfort. The
eight nights of enforced bivouacking which I was obliged to spend on
the top of Abu Hamamid in February 1906, before I could complete my
observations, belong to the least pleasant of my experiences in the
desert. A little work only was possible the first day, owing to haze
obscuring the more distant peaks. On the second day clouds enveloped
us in a wet drizzle, and a bitterly cold north wind blew with great
violence; a rude rubble shelter which my men built on the summit,
covered with a blanket, was a very poor protection, and I found it
better to throw a rubble embankment across a steep gully on the lee
side, forming a small level platform where we were sheltered from the
biting wind. For the next five days, we were alternately wrapped in
clouds or left free under a brilliant blue sky with clouds covering
all the surrounding country. It was curious on these days to look over
the surface of the clouds, as over a boundless level sea, with only
the highest peaks projecting sharp and black above the white surface,
and to see the sun rise and set exactly as though one were on the
ocean. Then at last the clouds began to disappear, and on the first
clear day a very large amount of triangulation was accomplished, all
the more prominent peaks within a radius of about sixty kilometres
being observed. Gebel Abu Hamamid forms a culminating point on the
Nile — Red Sea watershed, its eastern parts draining to Wadi Huluz
and its western ones to Wadi Abu Hamamid, a tributary of Wadi Kharit.
PLATE XII.
[Illustration]
[Illustration: Typical Views among the Mountains of Hamata and Abu
Hamamid. (The high peak in the distance in the lower view is Gebel
Hamata).]
=Gebel Um Semiuki= is a sharp cone rising to 1,283 metres above the
sea among a mass of lower hills three kilometres north-east of Gebel
Abu Hamamid. It is of a reddish aspect, due to a film which covers
the weathered surface of the green and grey hornfels of which it is
composed. It is drained by the Wadi Um Semiuki.
=Gebel Abu Argub= is a very conspicuous mountain, almost conical in
shape, seven and a half kilometres south-south-west of Gebel Abu
Hamamid, from which it is separated by lower hills. To the south,
Gebel Abu Argub overlooks the plain of Selaia. Its peak, 1,690 metres
above sea-level, is a good landmark from the south and west.
=Gebel Kahfa= is a many-peaked mountain of granite rising abruptly
to a height of 1,018 metres above sea from among lower hills of dark
schists, nineteen kilometres south-west of Gebel Abu Hamamid. It is
detached from the main mountain-mass, being separated from it by the
heads of Wadi Um Retba. Its faces are in many places sheer precipices
of several hundred metres (_see_ Plate XIII), but the ascent of it
from the north is not very difficult. In occupying Kahfa as a station
I approached it from Bir Shadli by a well-marked track which skirts
the western foot-hills and leads to the Wadi Helie. Leaving this track
where it crosses Wadi Um Hargal some six kilometres from Bir Shadli, I
ascended the Wadi Um Hargal and crossed the pass at its head into the
head of Wadi Um Retba, where I pitched my camp at an altitude of 563
metres, at the foot of Gebel Kahfa 1·3 kilometres north-north-east of
the beacon on its summit. The climb of 455 metres from this camp to
the top occupied three hours. There is good bivouacking ground close
east of the summit, between two ridges. The beacon which marks the
triangulation point is in latitude 24° 8′ 18″, longitude 34°
38′ 55″. A walk round the top is full of interest; one can reach
many points overlooking tremendous precipices, and the forms assumed
by the granite peaks are very remarkable. On the west side of the
mountain is a rather large open space forming the head of Wadi Helie,
but elsewhere one is surrounded by low hills. The principal drainers
of Kahfa are the Wadis Um Hargal and Um Retba (tributaries of Wadi
el Sheikh) to the north, and Helie and Abu Hashim (tributaries of
Wadi Kharit) to the south.
=Gebel Medsus= is a small group of high hills rising among lower
ones between Gebel Abu Hamamid and Bir Shadli.
=Gebel Metawit= is a high granite hill rising conspicuously among
much lower hills thirteen kilometres north-west of Bir Shadli. A
track leading from Bir Shadli to Bir Metawit and other wells further
north-west passes close east of the hill. Gebel Metawit is a good
landmark for Bir Metawit, which is situated in the wadi of the same
name about three kilometres north-west of it. The summit is 741 metres
above sea-level or about 295 metres above the wadi floor at the well.
=Gebel Hamrat Mukbud= is a great red granite mass rising from the
plain about twenty-five kilometres west of Bir Shadli. Its isolated
character and great altitude (892 metres above the sea and about
450 metres above the surrounding country) render Hamrat Mukbud one
of the finest and best known landmarks in this part of the desert. A
cairn on its summit marks the triangulation point, in latitude 24°
9′ 53″, longitude 34° 23′ 17″. Its ascent is a matter of
some difficulty, owing to its great steepness.
=El Hamra= is another red granite mass, much smaller than Hamrat
Mukbud, lying about half-way between that mountain and Bir Shadli,
and separating the Wadi Abu Hamamid from the Wadi el Sheikh.
=Gebel Homr Akarim= is a hill about thirty-three kilometres west
of Gebel Hamrat Mukbud, close to the north of Wadi el Khashab. Its
summit, 490 metres above sea, is marked by a triangulation cairn.
=Gebel Marasan= is a range of mountains north-west of Abu Hamamid. It
is cut through by an important pass over the main watershed, 685
metres above sea-level, connecting the Wadis Huluz and Abu Hamamid
by their respective tributaries Marasan and Marasani, which drain
north-east and south-west from the pass. The highest peak of the
mountains south of the pass is 1,261 metres above sea-level, while
those to the north are lower. The name Gebel Marasan is, however,
commonly given only to the peaks north of the pass, as they rise more
abruptly from it, while those to the south are unnamed or regarded
as part of Gebel Hamamid because the Wadi Abu Hamamid drains their
southern flanks.
PLATE XIII.
[Illustration]
[Illustration: Two Views on Gebel Kahfa. (Granite).]
=Gebel Khulla= is a range lying a few kilometres west of Gebel
Marasan from which it is quite separated. Its highest point is 978
metres above sea. It is drained by Wadi Khulla, a tributary of Wadi
Abu Hamamid.
=Gebel Um Sedri= is a remarkable pair of twin peaks on or near the
main watershed seventeen kilometres north-west of Gebel Abu Hamamid,
and a little to the south of the Wadi Huluz. These peaks, which are
970 metres above sea-level and about 460 metres above the floor of
Wadi Huluz, are very conspicuous from the surrounding high country,
but they cannot be seen from the Wadi Huluz itself as they lie a
little way back from the scarps which bound the gorge. It is the
drainage from the hills round Gebel Um Sedri which feeds the water
holes of Um Gerifat, in a little gorge opening to Wadi Huluz about
two kilometres north-west of the peaks.
=Gebel el Heda= is a conspicuous hill situated ten kilometres
north-north-west of Gebel Metawit, between the Wadis Antar and
Khashab. Its highest point is 862 metres above sea-level.
=Gebel Nukheira= is a group of high hills on or near the main
watershed, close to the head of Wadi Antar and about ten kilometres
north-north-west of Gebel el Heda. Its highest point is 876 metres
above the sea.
=Gebel Ras Abu Etl= is a lower hill seven kilometres north-east of
Gebel Nukheira. As seen from the upper part of the Wadi Gemal it
appeared to have a flat top, which is 648 metres above the sea. It
is probably drained by the short Wadi Abu Etl, which joins Wadi
Huluz to form the Wadi Gemal.
=Gebel Um Suerab= is a great high ridge of dark looking rocks,
surrounded by high flanking hills, rising conspicuously in the
hilly country between the Wadis Huluz and Gemal, about twenty-four
kilometres north-north-west of Gebel Abu Hamamid. The top of its
ridge, which appears to be nearly level for about a kilometre of its
length, is 1,024 metres above sea-level. From its neighbourhood drain
two wadis in opposite directions; one, called the Wadi Um Suerab lil
Gemal, goes northward to join Wadi Gemal, while the other, called
Wadi Um Suerab lil Huluz, is the longer and courses southward to
join Wadi Huluz.
=Gebel Durunkat= is another apparently flat-topped hill eight
kilometres south-east of Gebel Um Suerab, on the west side of the
Wadi Durunkat, about thirteen kilometres above its junction with
Wadi Gemal. Its summit is 924 metres above sea-level.
=Gebel Abarun= is a mountain range situated a short distance
north-east of Gebel Abu Argub, from which it is separated by the Wadi
Abarun. Its highest peak, almost due east of that of Abu Argub, from
which it is separated by the Wadi Abarun, is 1,602 metres above sea,
and overlooks the great plain of Selaia to the south.
=Gebel Um el Tiur= is a range extending south-east from Gebel Abarun,
forming a southward prolongation of the mountains. Its highest peak
is 1,450 metres above the sea, while the terminal peak southward is
1,080 metres. It is drained on the west by the Wadis el Shel and el
Anbat (tributaries of Wadi Kharit) and on the east by the Wadi Um
el Tiur (a tributary of Wadi Hilgit lil Kharit).
=Gebel el Anbat= is a group of lower dark coloured hills forming
the south foot hills of Gebel Um el Tiur. Its highest point is 788
metres above sea, while a detached black hill a little west of it
on the plain rises to 680 metres above sea, or 175 metres above the
plain at its base. These hills are drained by the Wadi el Anbat and
other small feeders of Wadi Kharit.
=Gebel Um Usher= and =Um Hasidok= are conspicuous peaks on the main
watershed ten kilometres east, and twelve and a half kilometres
east-south-east respectively of Gebel Abu Hamamid, rising to 1,487
and 1,497 metres above sea-level. They are drained to the south by
the Wadi Hilgit lil Kharit, and to the north by the Wadi el Mahali,
a feeder of Wadi Huluz.
=Gebel el Mahali= is a rather high peak of grey porphyry which forms
a northerly extension of Gebel Um Usher, close south of the Wadi
Huluz. Its top is 1,112 metres above sea, or 330 metres above the
adjacent wadi floor.
=Gebel Hamata=, with one exception[106] the highest mountain in
the Eastern Desert of Egypt, is situated on the meridian of 35°,
in latitude 24° 12′, thirty-three kilometres from the nearest
point of the coast and 213 kilometres from the nearest point of the
Nile, and rises to an altitude of 1,978 metres above sea-level; the
summit is marked by a triangulation beacon, the position of which is
latitude 24° 12′ 17″, longitude 35° 0′ 16″. Gebel Hamata
lies some five kilometres east of the main watershed, which curiously
enough is not always formed by the highest peaks. It is drained
principally by the Wadi Huluz, the heads of which almost encircle
it. The Wadi Hamata heads in the eastern face of the high ridge which
connects Gebels Hamata and Abu Ghusun, and thus only takes a small
portion of the drainage of Gebel Hamata itself. Though surrounded
by other high mountains, Hamata towers above them so as to be a very
conspicuous feature on the sky line from great distances. Looked at
from the north or south, it is like a great, rather flat, cone with
a smaller cone east of it. The best way to ascend the mountain is
from the head of the Wadi el Abiad, that feeder of Wadi Huluz which
drains the north face of it. In proceeding up the Wadi el Abiad
from Wadi Huluz, one is shut in by high hills on either side till
about six kilometres from the mountain; then the wadi opens into a
rough plain with low granite hills, and the imposing mass of Hamata
springs suddenly into full view. My camels were coaxed on with their
loads up this wadi, which becomes very steep and stony as its head
is approached, to within two and a quarter kilometres of the summit,
where they actually reached an altitude of 1,025 metres above the
sea. The ascent of the remaining 953 metres on foot, though tiring,
was fairly easy, and occupied less than four hours. The lower third
of Hamata is a whitish granite; this gives place higher up to a hard
quartz felsite, which rings under the hammer and weathers into rusty
brown blocks. To the east of the main summit the rock changes to a
green breccia, which seems to form a considerable portion of that
part of the mountain. The view from the summit is a fine one in
clear weather, including as it does an extensive prospect of the
rugged mountains around, and a large extent of coast-line. But it
was on this mountain that I had my first experience of the chronic
haze which seems to hang almost perpetually over the coastal regions
in the neighbourhood of the tropic, and which is the greatest enemy
of the surveyor in these parts. On each of the three days which
I spent on Hamata, the morning sun rose over cloud-banks to the
east; clouds filled all the wadis and covered the lower country,
while the highest peaks stood up clear and sharp above the sea
of cloud. Towards 10 a.m., the clouds gradually melted away over
the land under the increasing solar influence, but there remained
a continuous haze, especially over the coast and out to sea. The
explanation of the almost perpetual clouds and haze was soon seen,
and is very simple. If the wind blows from the north-west, it is
generally cool or even cold in winter. If this north wind is dry
and persistent, the air is clear; but should it fail and warm moist
breezes set in from seaward, these drop their moisture on reaching
the cooler air of the mountains. If the air is still or nearly so,
the moisture is evaporated in the sun’s rays during the day, only
to precipitate itself again as the air cools by rapid radiation at
night. As a consequence, dews on the mountains are extremely heavy,
and one soon learns to seek the shelter of an overhanging rock or to
improvise a rude tent from a blanket and a few sticks over one’s
nightly resting-place.
=Gebel Abu Ghusun= is a mountain range north of Hamata, with which
it is connected by a ridge of lower peaks so as to close in the
small rough granite plain north-east of the latter mountain. Its
highest peak, eight kilometres north-north-west of Gebel Hamata,
is 1,389 metres above sea-level. It is drained on the south by
the Wadi el Abiad, the same tributary of Wadi Huluz which drains
the north face of Hamata, and on the north by the Wadi Abu Ghusun,
which enters the sea separately.
=Gebel Um Laham= is a mass of lower hills a little west of Gebel Abu
Ghusun, forming the side of Wadi Huluz opposite to Gebel el Mahali.
=Gebel Tarfawi= is a complex mountain range fourteen kilometres
north-west of Gebel Hamata. Its highest point, at the north-west end
of a ridge, is 1,363 metres above the sea. It is probably drained
to the south by the Wadi Tarfawi, a tributary of Wadi Huluz, and to
the north by feeders of Wadi Romit.
=Gebel Um Heshenib= is a great ridge situated twenty-two kilometres
north-west of Gebel Hamata. The beacon on its highest point,
in latitude 24° 20′ 49″, longitude 34° 50′ 53″, has an
altitude of 1,135 metres above the sea. Its lower parts are granite,
but the upper third is of dark schists, while the actual ridge on
which the beacon stands is a grey porphyrite. Gebel Um Heshenib is
drained to the north by the Wadi el Abiad, a tributary of Wadi Gemal,
and to the south by tributaries of Wadi Huluz. I ascended it on two
occasions from opposite sides. The north approach is the easier road
for camels, as they can pass easily up the broad and sandy Wadi el
Abiad, while to reach it from Wadi Huluz one has to journey over
a rather stony pass and along narrow stony wadis. But the climb
is longer from the north side, being one of 635 metres against 380
metres from the south, and the southern climb is easier as well as
shorter. It is interesting to note that as the ground south of the
mountain lies at an average level of 250 metres higher than that to
the north, the plumb-line ought from theoretical considerations to
be attracted to the south by several seconds, and this was found
to be the case when the mountain was used as a latitude station
(_see_ p. 47) There is a very difficult pass east of the mountain
from the head of Wadi el Abiad into a tributary of Wadi Huluz; I
was told that loaded camels could not possibly get over the pass,
and have reason to believe the statement true, as although I did
not consent my men were desirous of going over it and volunteered
to carry the baggage over themselves to relieve the camels.
=Gebel el Abiad= is the name given to two distinct ranges of high
granite hills on either side of the Wadi el Abiad, north and east
of Gebel Um Heshenib. The eastern of these two ranges extends
in a north-westerly direction for about twelve kilometres from
Gebel Tarfawi to near the place where Wadi el Abiad turns to the
north-east. It has numerous peaks, of which the most conspicuous
is at the south-east end of a high ridge six and a half kilometres
north-east of Gebel Um Heshenib, and rises to 957 metres above
sea. This eastern range is drained from the west by the Wadi el Abiad,
and from the west by the Wadis Shoab and Romit. The western range is
slightly lower and less extensive; one of its most conspicuous peaks,
eleven kilometres north-north-east of Um Heshenib, is 892 metres
above the sea, and there are numerous other peaks further south of
almost equal altitude. This western range is almost entirely drained
by the Wadi el Abiad, a feeder of which curves round the south end of
the range, thus separating it from Gebel Um Heshenib; the drainage
from the north end probably passes into the Wadi Mukhatatat, while
a portion of the eastern slopes may be drained by feeders of Wadi
Durunkat. It is the coarse white granitic sand resulting from the
disintegration of the rocks of these hills which gives its name to
the Wadi el Abiad, and the hills take their name from the wadi. The
heads of the wadi near Gebel Um Heshenib are, however, blackened by
hornblendic downwash from the schists which overlie the granite of
that mountain.
=Gebel Shoab= is a very high white granite hill close to the head of
Wadi Shoab, on its north side. It rises to 830 metres above the sea,
or about 400 metres above the wadi floor.
=Gebel Hefeiri= is a very sharp granite peak a little west of the
Wadi Abu Ghusun, about fifteen kilometres north of Hamata. Rising to
612 metres above the sea, or about 300 metres above the wadi near it,
among lower granite hills, it is a good landmark. There is a smaller
very sharp peak two and a half kilometres to the north-east, on the
opposite side of the Wadi Abu Ghusun, while to the west are sugar
loaf shaped hills.
=Gebel Um Sueh= is a conspicuous granite hill six and a half
kilometres east of the Wadi el Abiad and four and a half kilometres
north of the Wadi Shoab, rising to 781 metres above sea. It is
probably drained from the north-east by the heads of Wadi Um el Abbas.
=Gebel Um el Abbas= is a very remarkable granite hill between Gebels
Um Sueh and Abu Hegilig. From the north, it looks like a square block
with precipitous sides, having a sheer drop of about 200 metres. Its
summit is 697 metres above sea. It is drained by the Wadi Um el Abbas,
which goes independently to the sea.
=Gebel Abu Hegilig= is another high granite hill, three and a half
kilometres east of Gebel Um el Abbas and twenty-six kilometres north
of Gebel Hamata. Its summit, 607 metres above sea, is marked by a
beacon, the position being latitude 24° 26′ 16″, longitude 34°
58′ 32″. The hill is drained by feeders of Wadi Um el Abbas. The
camp from which I ascended the hill was in one of these feeders 1,200
metres north-east of the beacon and 267 metres above sea-level; the
climb of 340 metres was not difficult, and only occupied a little
over an hour. The beacon is on a block not large enough to take an
instrument, so that observations here were taken from an eccentric
point a little way along the ridge and afterwards reduced to centre.
=Gebel Sarobi= is a small hill-range twenty-two kilometres north-east
of Gebel Hamata and some eleven kilometres from the sea coast. The
peak at its south end is 471 metres above sea-level. This range
has not been closely approached nor well seen, but it must be very
conspicuous to any one travelling in the low hill country near
the sea.
=Gebel Ras el Kharit= is a mountain range forming part of the main
watershed, running in a nearly east and west line a little south
of Gebel Hamata. Its highest peak is extremely sharp, and rises
to 1,661 metres above sea-level six kilometres south-south-east of
Hamata. Of the many other peaks of the range, the chief is one three
kilometres west of the highest point, and six kilometres due south
of Hamata; this reaches an altitude of 1,564 metres. The northern
face of the range is drained by the heads of the Wadi Huluz, while
the southern is drained by the heads of Wadi Kharit, whence the name
of the mountain range.
=Gebel Khashir=, which forms an eastward extension of Gebel Ras
el Kharit, reaches an altitude of 1,565 metres above sea-level;
its highest peak is nine and a half kilometres south-east of Gebel
Hamata. It is drained to the sea by the Wadi Khashir, the heads of
which end in the precipitous eastern faces of the mountain.
=Gebel Mikbi= is a long high ridge on the main watershed, seven
kilometres south of Gebel Khashir. Its highest point, at the south
end of the ridge, is 1,388 metres above sea-level. Gebel Mikbi
is connected with Gebel Ras el Kharit by a lower ridge running
north-west and forming the continuation of the watershed across the
head of Wadi el Kharit. There is a pass across this ridge into the
head of Wadi Mikbi, which drains Gebel Mikbi seawards, but it is a
very difficult one for loaded camels owing to the great steepness
of the eastern side.
=Gebel Zatit= is another high ridge about five kilometres east of
Gebel Mikbi, on the south side of the head of Wadi Mikbi.
=Gebel Egat= is a high mountain close to the south-west of Gebel
Mikbi, forming the continuation of the watershed. It has two principal
peaks, two and a quarter kilometres apart, of which the south-west
one is the higher, being 1,422 metres, while the north-east one is
1,277 metres above the sea. The western face of the mass is drained
by the Wadi Egat, a tributary of Kharit, while the eastern flanks
are cut up by feeders of the Wadi Sefent, a tributary of Wadi Lahami.
=Gebels Um Sellim= and =Gumudlum= are high hill ranges forming an
eastward extension of the Egat and Mikbi mountains, on the north side
of Wadis Sefent and Lahami. The highest point of Gebel Um Sellim is
947 metres above sea, or about 620 metres above the floor of Wadi
Lahami. These ranges are flanked by lower hills through which run
various small wadis such as Um Khuzuma, Um Ghobasha, and Gumudlum,
all feeders of Wadi Lahami. Some of these small wadis contain rock
basins or galts which retain large supplies of water for some time
after rain has fallen on the hills.
=Gebel Abu Gurdi= is a great mountain in latitude 24° 0′, forming
the terminal peak to the south of the Hamata group. The beacon on
its summit, in latitude 24° 0′ 11″, longitude 35° 5′ 17″,
is 1,562 metres above sea-level. Though in reality a ridge, Abu Gurdi
from most points of view looks like a rather flat cone, surrounded
by lower hills. It is on the main watershed, which crossing to the
summit from Gebel Egat, continues south-eastward along a narrow ridge
descending to the pass at the head of Wadi Lahami. The south-west
parts of Abu Gurdi are drained by the Wadis Abu Gurdi and Elemikan,
both tributaries of Kharit, while its southern and eastern parts
drain into Wadi Lahami by various feeders, of which the chief are the
Wadis Um Karaba, Um Rishan, Um Homar, and Sefent. Gebel Abu Gurdi
could probably be ascended from the west by following up the Wadi
Abu Gurdi, but in occupying the mountain as a triangulation station
I descended the Wadi Lahami as far as the point of influx of Wadi Um
Karaba and then ascended the latter wadi as far as the camels could
get, pitching my camp two kilometres south of the summit at 804 metres
above sea-level. The ascent of 758 metres to the beacon on foot from
the camp occupied two and a quarter hours of fairly stiff climbing;
it presented no serious difficulties, but the rock near the top is
much broken up and one has to be careful lest blocks are dislodged
under one’s foot. The view from the top of Abu Gurdi on a clear day
must be extremely fine, but during the three days I remained there
a thin haze spoiled the distant prospect, especially towards the
coast; the remarkable shapes of the granite peaks of Gebel Faraid,
sixty kilometres to the south-south-east, formed the most striking
feature in the scene.
=Gebel Derhib=, 1,160 metres above the sea, is a mountain separating
Wadi Abu Gurdi from Wadi Egat; it is really an extension of Gebel
Abu Gurdi, from the beacon on which its summit is six and a half
kilometres west.
=Gebel Um Goradi= is likewise in reality part of the Abu Gurdi mass,
forming the end of a spur extending south-eastward for ten kilometres
from the main peak. The Wadi Lahami curves round its foot northward,
passing between it and Gebel Um Gunud.
=Gebel Selaia=[107] (the bald head) is a very remarkable
rounded granite boss rising from the plain thirty-one kilometres
south-south-west of Gebel Hamata. Owing to its peculiar shape,
isolated position, and considerable height (its top is 787 metres
above sea-level and about 260 metres above the plain), Selaia
is a conspicuous landmark for great distances round it. The lower
illustration on Plate XI (p. 172) gives an idea of its appearance as
seen from the east; from the north or south it appears much steeper.
South-east of Gebel Selaia stretches a line of four smaller granite
hills. The first of these, about a kilometre from the great boss,
is interesting as having a small spring, called Megal el Selaia,
at its foot. The next, one and a half kilometres further on,
is larger, while the third is larger still, rising to 623 metres
above sea-level. The fourth, five kilometres from Gebel Selaia,
is marked by a triangulation beacon, 563 metres above sea-level and
about fifty metres above the plain, in latitude 23° 55′ 30″,
longitude 34° 54′ 37″.
=Gebel el Homur= is an isolated mass of granite hills on the plain
six kilometres north-east of Selaia. Its highest point is 731 metres
above sea and 230 metres above the plain at its foot. It is drained
by small feeders of the Wadi Abu Gurdi, which passes north of the
mass on its way across the plain to join Wadi Kharit.
=Gebel Abu Derega= is an isolated mass of higher granite hills
thirteen kilometres south-east of Gebel Selaia. Its highest point
is 831 metres above sea-level, and about 300 metres above the
plain. Gebel Abu Derega is on the Nile — Red Sea watershed, which
crosses the plain from east to west in this locality. The northern
drainage is to the Wadi Elemikan, which runs between Gebels Abu
Derega and Selaia to join Wadi Kharit, while the southern faces of
the hills are drained by feeders of the Wadi el Khiua, a tributary
of Wadi Um Bisilla, in the basin of Wadi Hodein.
Besides the hills above described, there are many smaller ones
scattered at intervals over the great sandy plain of Selaia,
but the only others calling for special notice are the three
very remarkable white conical hills called =Marwot Elemikan=,
situated twelve kilometres east of Abu Derega. These hills, though
small, are conspicuous from considerable distances, owing to the
dazzling appearance of the pure milk-white quartz of which they are
composed. The highest and most northerly one, with a triangulation
beacon on its summit, rises to 648 metres above sea, or 68 metres
above the plain, in latitude 23° 54′ 14″, longitude 35° 6′
8″. The other two lie about two kilometres south-east and south
respectively, with a black hill mid-way between them.
=The Um Gunud — Dahanib — Batoga Group.=
The mountains of this group, occupying the country east of the
watershed between Wadi Lahami and Wadi Khoda, are considerably lower
than those of the preceding two groups, only a few peaks rising
more than 1,000 metres above sea. The north portion of the group
is formed by the line of mountain ridges which as seen from the
sea near Berenice appears to connect Gebel Kalalat with Abu Gurdi,
while the south part spreads further east and west and contains the
highest peaks.
=Gebel Um Gunud= is the northernmost mountain of the range west
of Berenice. It is a dark rugged ridge, surmounted by a cairn[108]
989 metres above sea-level, forming the east side of the Wadi Lahami
opposite Gebel Abu Gurdi. It is drained from the west by the Wadi Um
Gunud, a feeder of Wadi Lahami, and on the east by feeders of Wadi
Naait. Gullies in the west flanks of the mountain contain rock basins,
called Galt Um Gunud, which hold water supplies for a long time after
rain has fallen, and which are fairly easy of access from Wadi Lahami.
Gebel Eidab, the next member of the range to the south, rises to
848 metres above sea. It is drained on the west by the Wadi Eidab,
a tributary of Wadi Lahami, and on the east by the Wadi Abu Daba, a
tributary of Wadi Mukhit; a rough and steep pass is said to exist from
east to west between the heads of these two wadis near the mountain.
=Gebel Um Maiat=, a long high ridge stretching south-east from Gebel
Eidab, has three marked summits near its ends and centre; that at the
north end, which is the highest, is 928 metres, while the other two
are 870 and 842 metres above sea respectively. Another broken ridge,
of similar height, for which I could get no name from my guides,
forms a south-eastern prolongation of Um Maiat, and extends to
the Wadi Kalalat; this likewise has three well defined summits,
rising in order from north to south, to 875, 821, and 627 metres
respectively. These ridges are drained to the east by the Wadis
Murra (tributary of Abu Daba) and Mindeit. Their western drainage
has not been studied in detail, but it all reaches the sea, none of
it going Nilewards; part of the drainage is probably taken by each
of the Wadis Kalalat, Shut, and El Khiua.
To the east and north-east of the Um Gunud — Eidab — Um Maiat
range is a great expanse of lower hill country through which the
wadis cut their way eastwards for about fifteen kilometres to the
coast plain. The most conspicuous peaks in this lower hill country
are Gebels Um Huk, Abu Ghalqa, and Um Hegilig, all situated in its
north portion round about Wadis Lahami and Naait. Other low rugged
hills fill a triangular tract south-west of the main range.
=Gebel Um Huk= is a sharp granite peak, surmounted by a cairn,[109]
rising to 517 metres above sea-level near the south side of Wadi
Lahami, fourteen kilometres north-north-east of Gebel Um Gunud.
=Gebel Abu Ghalqa= is another high granite hill, also marked by a
cairn on its summit, seven kilometres south-south-east of Um Huk. The
cairn is 561 metres above sea-level, and is in latitude 24° 1′
7″, longitude 35° 16′ 47″.
=Gebel Um Hegilig= in a small rather spiky range of red granite
hills situated a little to the north-east of Gebel Um Gunud, near
the heads of Wadi Naait.
To the north-west of Berenice are several low hills on the coast
plain, which serve as landmarks and bear special names. =Grain el
Rih= is a conspicuous isolated low hill nearly opposite the place
where Wadi Naait emerges from the hills on to the plain, thirteen
and a half kilometres north-west of Berenice. =Khasheib Abu Daba=
is the name of some low bouldery granite hills at the place where
Wadi Abu Daba enters the plain. =Sikeit=, a landmark for Berenice,
from which it lies five kilometres north-west, is a low granite hill,
isolated on the plain and very conspicuous; its summit is seventy
metres above sea-level, or thirty-eight metres above the plain at
its foot.
The =Hills on the Peninsula of Ras Benas= are sharply marked off
into two portions by differences of colour. The most striking are the
dazzling white hills of gypseous limestone which form a narrow sinuous
broken plateau nearly along the long axis of the peninsula. The
highest points of these white hills are 188 metres above the sea. Deep
ravines cut up the plateau and separate it into more or less detached
hills. The surface of the gypseous rock is very rough, and frequently
weathered into knife-like projections which cut one’s hands and
boots badly in climbing. Near the tip of the peninsula the gypseous
beds contain a little sulphur in places, and there are some shallow
pits which seem to have been dug for exploiting that mineral. But
the quantity appears far too small to be of any commercial value,
and the pits were probably only exploratory trial holes.
The other hills on the peninsula are darker in colour, being chiefly
diorite. They form two masses, one near to where the peninsula joins
the main land, and the other on the south side of the peninsula twenty
kilometres east of Berenice. The highest point of the first-named
group is 276 metres, while that of the second is 197 metres, above
sea-level. All the hills on the peninsula are quite separated from
those of the main land by the broad sandy plain through which Wadi
Mukhit courses south-eastwards to the sea.
=Gebel Batoga=, a granite mountain fifteen kilometres south-east
of Berenice, is sharply marked off from the other mountains near
it by its light colour. It is a great boss of acid granite seamed
with dykes, having two main peaks. The highest (central) peak rises
to 802 metres above sea-level; the southern peak, surmounted by a
triangulation beacon in latitude 23° 49′ 37″, longitude 35°
21′ 9″, is seventeen metres lower. Gebel Batoga is drained
from the north by feeders of the Wadi Kalalat, and from the south
by the Wadi Kunserob. There is a good water source, Galt Batoga,
at its north-east foot, consisting of a rock basin which holds a
good supply of water for a long time after rain, situated in a small
gully close to the Wadi Kalalat, the floor of which is here about
160 metres above sea-level.
=Gebel Kalalat=, situated about six kilometres west of Gebel Batoga,
is a mass of ridges, higher and darker in colour than Batoga. Its
highest point, marked by a beacon in latitude 23° 49′ 9″,
longitude 35° 17′ 36″, is 1,125 metres above the sea, while
another conspicuous peak one and a half kilometres north-east
of the beacon, rises to 1,080 metres, and there is a third peak
three and a half kilometres south-east of the beacon which attains
894 metres. In ascending Gebel Kalalat to occupy the triangulation
station, I followed up the Wadi Kalalat to where the little winding
Wadi Um Maiat enters it from the south, then turned up the latter wadi
and pitched my camp as far up as the camels could go. The camp was
three kilometres north-east of the beacon and 300 metres above sea,
so that the climb to be made on foot was 825 metres. Though long
and tiring, the ascent to the beacon was not dangerous. Further up
the head of the wadi than my camp, I came on a line of galts (rock
basins) containing rain water, but they were not easy of access
to camels, being in a steep and stony gorge. Perched on the east
flank of Kalalat is a very remarkable pinnacle rock, well seen in
the illustration on Plate XIV. A very good view of the surrounding
mountains is obtained from the summit in clear weather, but the top
was wrapped in clouds for a great part of two out of the four days I
remained on it. Gebel Kalalat is drained from the north by feeders
of the Wadi Kalalat, and from the south by the Wadis Gumudlum and
Kunserob. Wadi Kalalat curves round the north-west side of the mass,
and it is possible that the ascent might be easier by following
that wadi as far as possible and climbing up the north-west face of
the mountain. A rough steep pass, impracticable for loaded camels,
is said to lead from the head of Wadi Kalalat into Wadi Shut.
=Gebel Dibag= is a high dark ridge five kilometres south of Gebel
Batoga, with a peak at each end. The north-west peak is 517 metres,
and the south-east one 544 metres above sea-level. The Wadi Kunserob
curves round its east and south flanks, while the Wadi Dibag lil
Kunserob drains its eastern face into the same channel.
=Gebel Shenshef= is a mass of high dark hills between the Wadis
Shenshef and Gumudlum, close to the Wadi Khoda. On one of its eastern
peaks, situated in latitude 23° 44′ 5″, longitude 35° 22′
40″, on the west side of Wadi Shenshef, and not so high as others
further west, a beacon has been erected overlooking the ruins called
Hitan Shenshef. There are wells in the wadi a short distance below
this hill. The beacon is 290 metres above the sea and 115 metres
above the wadi floor at its foot.
=Gebel Dahanib= is a mountain of dark coloured rocks (diorite and
gabbro), situated twelve and half kilometres south-east of Gebel
Kalalat and eleven kilometres north of the Wadi Khoda. Its summit,
on which is a triangulation beacon, is in latitude 23° 45′ 44″,
longitude 35″ 11′ 10″, and 1,270 metres above sea-level. Gebel
Dahanib is surrounded by other mountains and hills, and access to it
is not very easy. In order to reach it from Gebel Kalalat I had to
make a journey down the Wadi Kalalat, along the coast-plain and up the
Wadis Khoda and Allawi, a total distance of over eighty kilometres,
although the direct distance between the two peaks is only twelve and
a half kilometres. By ascending one of the heads of the Wadi Allawi
until camels could get no further, I was able to pitch a camp 540
metres above sea-level and three kilometres south-west of the beacon,
leaving 730 metres to be climbed on foot. The ascent, though tiring,
was free from difficulties or dangers, and occupied two and a half
hours. A galt, containing only a small supply of water at the time
of my visit, exists a little further up the head of the wadi than
where I fixed my camp. There is a good view from the summit, but in
the winter months Dahanib, like all the mountains near the coast,
is frequently wrapped in clouds for days together. Of seven days
spent on the summit in February 1907, three were passed entirely in
clouds, while only portions of the other four were free from fog
or haze. It was on Gebel Dahanib that I first noticed the curious
electric phenomena which may be observed at high stations when
electrified clouds are passing close overhead, my attention being
first drawn to them by a spark from the eye-piece of my theodolite
striking me over the eye. At the same moment a rapid succession
of sparks a centimetre or so long passed between my hand and the
adjusting screws of the instrument, while both the theodolite and
my hair hissed loudly. In this and all other cases of a like kind,
I judged it best to suspend operations for a time and descend a
little below the summit till the cloud had passed over.
Gebel Dahanib is drained by the Wadis Allawi, Um Tawil, and Shut, all
tributaries of Wadi Khoda, which course for a considerable distance
through the surrounding hills before reaching the main trunk wadi.
PLATE XIV.
[Illustration: Gebel Kalalat.]
[Illustration: Summit of Gebel Faraid. (Granite).]
Gebels Um Hegilig, Reyan, and Shut, are high hills situated between
the Wadis Shut and Gumudlum, both tributaries of Khoda. =Gebel Um
Hegilig=, a dark peak rising to 966 metres above sea-level, is almost
exactly midway between Gebels Dahanib and Kalalat. =Gebel Reyan=,
a little further south-east, is a group of peaks and ridges of which
the highest point is 863 metres above sea. =Gebel Shut=, the most
remarkable of the three, is a great cone rising to 930 metres above
sea, about five kilometres north of the Wadi Khoda. A very large galt
is said to exist among these hills, approachable from Wadi Shut;
it is probably in one of the feeders draining westward from Gebel
Reyan, which name signifies “the wet mountain.”
=Gebel Um Bisilla= is a dark mountain of gabbro rising conspicuously
among lower hills twenty-two kilometres west of Gebel Dahanib. The
triangulation beacon on its summit is in latitude 23° 45′ 34″,
longitude 34° 57′ 39″, and 824 metres above sea-level. Gebel Um
Bisilla is drained by Wadi Um Bisilla, the head of which encircles its
southern half, while the northern flanks are drained by feeders of
the Wadi el Khiua, which courses south-west to join Wadi Um Bisilla
about ten kilometres west of the mountain. There is an easy passage
for camels round the east side of the mountain from the head of Wadi
Um Bisilla into a feeder of Wadi Abu Nilih, a tributary of Wadi El
Khiua. In ascending the mountain I pitched my camp in one of the
gullies draining from it to Wadi Um Bisilla, at an altitude of 513
metres above sea and 1,300 metres south-east of the beacon. The climb
of 311 metres from this camp to the summit presented no difficulties,
and occupied only an hour and a half.
=Erf el Gimal= is a high dark ridge surrounded by lower hills ten
kilometres west-south-west of Gebel Um Bisilla. Its highest point,
the west end of the ridge, is 673 metres above sea. About seven
kilometres further west is a conspicuous conical hill called =Gebel
Abu Shigelat=.
=Gebel Zergat Naam=, sometimes called =Hagar el Fil=, is a mountain
mass on the main watershed thirty kilometres west of Gebel Um
Bisilla. It forms a curved range round the head of the Wadi el Kreim,
a tributary of Garara. Its northern part is drained partly by the Wadi
Abu Had, a feeder of the Rod el Kharuf, and partly by the heads of
the Wadi el Fil, which is itself the head of Wadi Naam. The highest
peak of the range is a conical one near its south end, 845 metres
above sea-level, but the northern peaks are more conspicuous from
some points of view, and it is on the highest of these, 823 metres
above sea, in latitude 23° 45′ 28″, longitude 34° 40′ 34″,
that the triangulation beacon has been erected. My camp at the
base was in one of the heads of Wadi el Fil, 527 metres above the
sea, and about 700 metres north-east of the beacon. The ascent from
here on foot to the beacon was fairly easy. Zergat Naam is a mass of
syenite rising through schists, but the northern summits are formed by
east and west bands of a very hard quartz felsite. From the summit,
looking northwards one sees long lines of north-and-south felsite
dykes forming ridges on either side of the head of Rod el Kharuf,
while close south of one is the enclosed sloping plain across which
run the feeders of Wadi el Kreim. To the south-south-east, a range
of lower hills runs north-westward from the end of the main range,
and between the two there appears to be a remarkably sudden drop into
the head of Wadi Abu Seyal. The Arabs state that there is a very
large galt at this point, reached by ascending the Wadi Abu Seyal;
the galt is said to hold water for five months after rain. But during
my occupation of the station recent rains had filled other smaller
rock basins in the gullies to the north, and it was unnecessary to
send far from the camp to get supplies. It is interesting to observe
from the summit of Zergat Naam the disposition of the rocks forming
the lower hills to the south and west; these are of sandstones with
marked dips, the area being one of much disturbance by faulting
along the Wadi el Kreim.
On the great sandy plain to the north and north-east of Zergat Naam
are two extensive groups of low hills, which stand out remarkably
owing to their dark colour. One of these groups, twenty kilometres
north of Zergat Naam, is called =Gebel Geneina Gharbi=; it is
a mass of hills composed chiefly of dioritic and gabbroid rocks
(through there are some schists and granites intermingled) and is
drained northward by the Rod el Geneina, a feeder of Wadi Kharit. The
other group, called =Gebel Geneina Sharqi=, is smaller and situated
fifteen kilometres further east; I did not visit it, but from its
dark colour it is probable that it consists of similar rocks to those
above-mentioned. The hills of both groups rise to about 550 metres
above the sea, or about eighty to one hundred metres above the plain.
In the low country to the west of Zergat Naam, between the Wadi
Garara and the Rod el Kharuf, the most conspicuous hills are =Erf
el Dubeis=, a ridge twenty-six kilometres due west of the beacon,
=Gebel el Nikeiba=, a granite hill marked by a triangulation cairn,
570 metres above sea-level and thirty-four kilometres west-north-west
of Zergat Naam; =Gebel Felieiti=, a sandstone hill, also marked by
a triangulation cairn, 500 metres above sea and sixteen kilometres
south-west of Gebel Nikeiba; =Erf Abu Homur=, a ridge at the head of
Wadi Abu Homur (a tributary of Garara), about seven kilometres north
of Gebel Felieiti; =Erf el Mohaib=, marked by a triangulation cairn
465 metres above sea-level, about nine kilometres north-west of the
last-named hill; and =Gebel el Ghar=, a hill on the south side of
Wadi el Kharit, close to the point where the Rod el Kharuf enters it.
=The Abu Dahr — Orga — Um Tenedba Group.=
The mountains of this group occupy the tract between the Wadi Naam
and Gebel Faraid, and are limited on the south by the Wadi Hodein.
=Gebel Abu Dahr=, the highest mountain of the group, is a great
mass of serpentine, situated in latitude 23° 35′ and about forty
kilometres from the coast. Its summit, marked by a triangulation
beacon in latitude 23° 36′ 8″, longitude 35° 5′ 46″, is
1,131 metres above sea-level. Its western face is drained by the heads
of Wadi Betan, its north-east flanks by those of Wadi Khoda, and its
south-east parts by feeders of Wadi Rahaba. Abu Dahr is surrounded
by high hills except on the west, where there is low hilly country
containing the wells of Betan and the old mining ruins of Um Eleiga
(_see_ Plate IV, p. 30). The mountain can be most easily reached
either by following up the Wadi Betan to its head, or by ascending
the Wadi Salib el Azrak (a tributary of Wadi Khoda) and its feeder
the Wadi Um Karaba. There is an easy pass 1,800 metres north of the
beacon, between the central mass of Abu Dahr and the high hills north
of it, connecting the heads of Wadi Betan and Wadi Um Karaba. A
short distance to the south-west of this pass there is a galt in
a spur of the mountain which holds water for some time after rain,
and which furnished supplies during my stay at the place in 1907. In
occupying the triangulation station, I fixed my camp in a small stony
wadi draining from the north of the mountain, on the east side of
the pass just referred to; the camp was 600 metres above sea-level
and 1,200 metres north-north-east of the beacon. The ascent, which
occupied three hours, was rather difficult and dangerous, the mountain
being not only steep[110] but composed of rotten highly crushed rock
which came away in tons at a mere touch. There is a very extensive
view from the summit, the striking peaks of Faraid being a marked
feature to the east and south-east, while to the south are the great
masses of Mishbih, Niqrub and Gerf, with the sandstone plateaux of
Dif, Hodein and Abraq limiting the view to the south-west. The rock
of Gebel Abu Dahr is highly magnetic, and several pieces which I
examined showed strong polarity. The compass needle points in all
sorts of directions as one moves about the mountain.
Gebel Abu Dahr and the high hills round it, especially to the south,
form an important rain-collecting area, the drainage from which feeds,
wholly or in part, the wells of Betan, Rahaba, Abu Reye, Abu Beid, and
Gahlia, all of which are within a radius of about fifteen kilometres
of the summit of the mountain. The relative abundance of water in
this area is caused by two main factors. In the first place, the
situation of the mountain on the eastward side of the watershed, only
about forty kilometres from the coast, and its considerable height,
condition the frequent accumulation of clouds about its summit, with
relatively high rainfall as a consequence. And in the second place,
the steepness of the slopes, and the fact that the serpentine rocks
are not only of an impermeable nature, but are so crushed that the
downwash into the gullies around is chiefly composed of smooth faced
blocks rather than of absorbent sand, condition a higher ratio of run
off to rainfall than exists in the case of most other localities in
the Eastern Desert. A similar state of things is found in the case
of Gebel Gerf, which, as will be mentioned further on, likewise
consists of serpentine and is the centre of a district relatively
rich in good wells; while in the case of the mountains of Faraid,
which are much higher and closer to the sea, but consist of granite
weathering into sand, though the rainfall is probably greater, the
absorption by the sand is so rapid that there are no wells known to
exist in their neighbourhood.
Between Gebel Abu Dahr and Gebel Um Bisilla there are three remarkable
little groups of granite hills. =Gebel Abu Arta= is a small range
of red peaks six kilometres south of Um Bisilla; =Gebel Hendusi=,
five kilometres further south, is a very conspicuous sharp granite
peak rising to 678 metres above the sea and forming a good landmark;
while =Gebel Abu Husenat=, four kilometres east of Hendusi, has
another well-marked peak rising to 725 metres above sea-level.
=Gebel Abu Sieiyil= is a many-peaked hill range running north and
south for about four kilometres, situated eight kilometres west
of the beacon on Gebel Abu Dahr. It has the appearance of being
composed of a pink gneiss, but has not been visited. Its central
peak, fixed by triangulation, is 833 metres above sea. The Wadi Abu
Beid el Azrak runs south-westward past the south end of the range,
through a gap between it and a smaller hill range to the east.
=Gebel Arais= is a considerable range of gneiss peaks situated on
the east side of Wadi Naam in latitude 23° 34′. One of the most
conspicuous of its many summits is a pair of twin peaks near the
south end of the range, rising to 613 metres above the sea. The
range is cut through from east to west by the narrow and winding
Wadi Arais, a tributary of Wadi Naam. The drainage from the western
faces of the range passes by many feeders over a sandy plain to join
the Wadi Naam directly.
=Gebel Belamhandeit= or =Erf Um Araka= is a long range of granite or
gneiss hills north of Gebel Arais. It extends for a length of nine
kilometres in a north-and-south direction on the meridian of 34°
50′. It is drained on the north and west by the Wadi Erf Um Araka,
a tributary of Wadi Naam, and on the east by the Wadi Belamhandeit,
a tributary of Wadi Arais.
To the east of Gebel Belamhandeit are several granite bosses, of
which the most conspicuous is called =Gebel Um Guruf=; it is drained
by the Wadi Um Guruf, a tributary of Wadi Arais.
=Gebel Orga=, eighteen kilometres south by east from Gebel Abu
Dahr, is a high dark-looking range which has not been closely
approached. Its highest peak, surmounted by a beacon, the position
of which has been fixed by triangulation, as latitude 23° 26′
21″, longitude 35° 8′ 17″, is 682 metres above sea-level. It
is drained by the Wadi Orga (a tributary of Wadi Hodein), which
contains the well called Bir Orga.
=Gebel Um Tenedba= is a mass of dark hills of crushed basic rocks
situated thirty kilometres south by east from Gebel Abu Dahr and
twelve kilometres north of the Wadi Hodein. Its highest point,
marked by a triangulation beacon, is in latitude 23° 19′ 48″,
longitude 35° 10′ 40″, and 654 metres above sea-level. It is
drained by the Wadi Um Tenedba, a tributary of Wadi Hodein. The
ascent of the hill is conveniently made in about an hour from a camp
in one of the heads of Wadi Um Tenedba, about 1,200 metres south-east
of the beacon and 320 metres above sea-level.
=Gebel Harhagit= is an isolated granite boss rising among schists ten
kilometres south-south-east from Gebel Um Tenedba and five kilometres
north of the Wadi Hodein. The beacon on its summit is in latitude
23° 14′ 35″, longitude 35° 12′ 52″, at an altitude of 542
metres above sea-level, or 326 metres above the wadi encircling its
base. From its isolated character Gebel Harhagit is a conspicuous
landmark for considerable distances round the Wadi Hodein.
=Gebel el Anbat= is conveniently considered here, though it lies
on the south side of the Wadi Hodein. It presents a somewhat
similar appearance to Gebel Harhagit, from which it lies nineteen
kilometres south-east, and like it bears a beacon on its summit. The
position of the beacon is latitude 23° 6′ 5″, longitude 35°
19′ 27″. El Anbat is lower than Harhagit, being only 390 metres
above sea-level; it consists also of a different rock, being chiefly
composed of curious brown and reddish calcareous schists. Gebel el
Anbat is practically in the Wadi Hodein, the main channel of which is
deviated by its foot-hills so as to pass round the east side of the
hill. It is best ascended from the south, where a camp can be fixed
about 600 metres south of the beacon and about 255 metres below it;
the ascent is easy and occupies less than an hour.
Eastward of Gebel Abu Dahr there extends for some thirty kilometres
along the south side of Wadi Khoda a mountainous tract of dark rocks,
the principal masses of which, from west to east, bear the names
of Gebel Hindia, Gebel Um Akra, and Gebel Um Etli. These mountains
have only been seen from a distance, and little is known about
them beyond the positions and altitudes of their principal peaks,
which have been fixed by triangulation. =Gebel Hindia=, thirteen
kilometres east of Abu Dahr, rises to 873 metres above sea-level,
and is drained partly by the Wadi Hindia to the north, and partly
by the Wadi Salib el Azrak. =Gebel Um Akra=, six kilometres further
east, is higher, its highest peak, marked by a beacon, being 1,050
metres above the sea, while a ridge a little further south reaches
970 metres; it is drained to Wadi Khoda by the Wadi Um Akra. =Gebel
Um Etli=, which forms the south side of the Wadi Khoda just before
that wadi emerges on to the coast-plain, has three main summits,
reaching respectively to 844, 795, and 764 metres above the sea. It
is a rather extensive mass, drained on the north by the Wadis Buluk
and Um Lassaf, tributaries of Wadi Khoda, and on the south by the
Wadi Um Etli, which reaches the sea independently.
=The Faraid Group.=
The mountains of this group cover a tract about forty kilometres in
length from north to south, between the Wadis Um Etli and Rahaba and
lie closer to the sea than any other mountains in the area described,
their peaks being only ten to twelve kilometres from the coast. They
consist entirely of granite, weathered into a forest of peaks the
forms of which render them in respect of shape the most remarkable
mountains in Egypt. There are four main masses in the group,
of which the three northern ones are called collectively Faraid,
while the southern one, which is smaller than, and separated from,
the rest, is called by the diminutive name Fereyid.
The most northern mass of =Gebel Faraid= is the highest, its principal
peak, situated in latitude 23° 33′ 7″, longitude 35° 22′
10″, being 1,366 metres above sea-level. As seen from the north,
this mass appears somewhat like an outspread hand, its western peak
seeming to overhang slightly like a thumb, while the higher eastern
peaks resemble fingers. The name _Mons Pentadactylus_ given to the
mountain in antiquity, and quoted by Ptolemy, would appear to have
referred only to this northern mass, and not to the Faraid group as
a whole.
The second mass presents from most aspects the form of a nearly
flat-topped mountain with a little peak on it and very steep
sides. Its highest point, situated in latitude 23° 30′ 53″,
longitude 35° 20′ 25″, is 1,259 metres above sea, and forms a
main triangulation point; it is too sharp to support an instrument or
even a beacon, and observations had to be taken from an auxiliary
station a little distance away from the summit and reduced to
centre. In ascending this peak as a survey station I approached
it from the west by the Wadi el Abiad and Wadi Abu Ribian, placing
my camp close under the mountain, on a sandy plain 450 metres above
sea-level and one and a half kilometres north-west of the summit. The
climb of 800 metres was steep, but not dangerous, and occupied about
three hours. The lower illustration on Plate XIV (p. 192) shows the
top of the mountain; the lower of the two peaks is the one occupied
for triangulation.
The third mass of Faraid is a great expanse of peaks extending over
eighteen kilometres north and south and some twelve kilometres east
and west. Its highest peak, called “The Bodkin” by the Admiralty
surveyors, has the position latitude 23° 28′ 58″, longitude 35°
20′ 35″, and rises to 1,232 metres above sea-level, dominating
the rest of the mass both by its height and its singular form;
it is a great sharp pinnacle, apparently unclimbable, visible from
distances of over 100 kilometres in nearly all directions, and a very
conspicuous landmark. South and west of “The Bodkin” are numerous
other peaks, some of which have been fixed by triangulation; several
of them rise to over 900 metres above the sea, and the whole forms
a compact mass across which there appears to be no passage for camels.
=Gebel Fereyid=, the fourth and most southerly of the masses
constituting the Faraid group, is a small spiky range quite detached
from the rest, about seven kilometres north of the Wadi Rahaba. It
has two main peaks, close together, of which the north-western one
is slightly the higher and is surmounted by a beacon, 612 metres
above sea-level, in latitude 23° 17′ 29″, longitude 35° 22′
48″. In occupying this peak as a triangulation station, the camp
was fixed in one of the heads of a nameless wadi draining past the
north face of the mountain to the sea, at an altitude of 200 metres
above sea-level and 850 metres north-north-east of the beacon. The
ascent was easy till within about fifty metres of the summit, when
it became difficult and rather dangerous, and there is very little
room on the top. I had to remain six days on this mountain owing to
almost continuous haze and clouds blocking the view.
The drainage from the western faces of the entire Faraid group
is taken by the Wadi Rahaba. That from the peaks north of “The
Bodkin” is collected by the Wadi el Abiad and its feeders the Rod
Elbel and Wadi Abu Ribian, while the more southern parts are drained
by various other tributaries of Wadi Rahaba, of which the principal
are the Wadis Dagalai lil Rahaba, Abu Had, and el Marafai. The heads
of Wadi el Abiad and its feeders cross a sloping sandy plain which
flanks the main peaks on the west. Of the eastern drainage, less has
been seen; the two principal drainers of the eastern face appear to
be the Wadis el Sorubiab and Bint el Kurdum, which unite together
in a small lagoon close to the coast in latitude 23° 30′. The
head of the Wadi Bint el Kurdum is between “The Bodkin” and the
flat-topped mountain to the north of it, and from the summit of the
latter it appeared as though there might be a possible pass by it
across the range into the heads of Wadi Abu Ribian; but I did not have
an opportunity of testing this. The foot-hills are only some five or
six kilometres from the coast near the north parts of the range, but
as one goes south the width of the coast-plain increases somewhat,
and is about twelve kilometres near Gebel Fereyid. Notwithstanding
the height of the Faraid mountains, their proximity to the coast,
and the clouds they frequently attract, there appear to be no wells
in the wadis draining from them; the explanation is probably to be
sought in the fact that the weathering of the granite of which they
are composed produces large expanses of coarse sand round their feet,
in which the rainfall is rapidly absorbed.
=The Awamtib — Abraq — Dif — Aqab el Negum — Mishbih Group.=
The mountains of this large and irregular group occupy the western
parts of the great drainage basin of Wadi Hodein, some of the
chief of them forming the main watershed separating that basin from
those of the Wadis Kharit and Alaqi. The northern mountains of the
group are high broken sandstone plateaux, while the southern ones
consist largely of granite. The sandstone ranges of Abraq, Hodein,
and Dif are remarkable for the numerous springs at their bases,
which render this district (_see_ the large scale map on Plate XV)
one of great importance to travellers.
=Gebel Awamtib= is the highest peak of a great mass of high sandstone
hills forming the main watershed between latitudes 23° 20′ and
23° 30′ and extending for some eight or ten kilometres on either
side of the meridian of 34° 30′. The highest peaks of the mass are
mostly well to the west of the actual watershed, and the principal
drainage channels run westward, those to the east, the feeders of
Wadi Muegil, being shorter. Gebel Awamtib is near to the south-east
corner of this mass, and is itself situated about six kilometres
west of the watershed. It is nearly separated from the surrounding
hills by wadis, and forms a conspicuous peak from the west; but the
neighbouring hills approach it so nearly in height that it is not
so easily distinguished from the east. It may, however, be picked
out by the triangulation beacon which marks its summit, 793 metres
above sea-level, in latitude 23° 20′ 59″, longitude 34° 26′
39″. Gebel Awamtib is drained westward by the Wadi Awamtib (a
tributary of Wadi Timsah), the heads of which nearly surround it. In
occupying the station I pitched my camp in a small feeder of the Wadi
Awamtib, two and a quarter kilometres south-west of the summit and 456
metres above sea-level. The climb from this place was easy enough,
but rather long, and on reaching the top I found it would have been
better to have approached the mountain by another feeder almost due
west of the beacon, as by this means a camp could have been placed
much closer and the ascent would not have been more difficult. It
is inadvisable to ascend from the east face of the mountain, for
although one of the wadi heads passes close east of the beacon, the
slope on that side is extremely steep and probably unscalable. The
top of the mountain is formed of large sandstone blocks under which
one can get good shelter from dews, though with little head-room. The
view from it is shut in to the east by the peaks of Gebel Shebakhit,
only two kilometres distant; but the peaks of Gebels Um Harba
and Zergat Naam can be seen to the north, while to the south and
south-east one looks out over high sandstone hills in the foreground
to the granite peaks of Gebels Shigigat, Aqab el Negum, Etresia, Um
Reit and Saalek. The most striking thing round Awamtib itself is the
strong westward dip of the sandstone beds of which it is composed,
which has conditioned the drainage and the steep eastern face.
=Gebel Shebakhit= is a group of high sandstone hills a few kilometres
north of Awamtib. It is drained north-westward by the broad Wadi
Shebakhit, a tributary of Wadi Timsah.
=Gebel Dagalai=, the next member of the sandstone hill-mass to
the north, has numerous peaks ranging from 670 to 712 metres above
sea. It is drained north-westward by the Wadi Dagalai, in which it
is said that water can sometimes be obtained.
PLATE XV.
[Illustration: MAP OF THE DISTRICT OF ABRAQ & ABU SAAFA
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
=Gebel Um Khafur= is a group of high sandstone ridges overlooking
the sandy plain of Um Harba to the north. One of its higher ridges,
560 metres above sea-level, bears a triangulation station, marked by
a beacon, in latitude 23° 29′ 54″, longitude 34° 29′ 19″. A
remarkable feature of Gebel Um Khafur is the north-north-easterly dip
of its sandstone beds at an angle of about 13°, almost constant over
a large area, with probably step-faulting parallel to the strike of
the beds; owing to these features there are developed a series of
long ridges, with a flat dip slope northward and a steeper drop to
the south, while the drainage channels run along the lines of strike
and only break across the ridges at a few points. The drainage from
these channels, the chief of which is called the Wadi Um Khafur,
meanders northward over the plain to join a feeder of Wadi Garara.
=Gebel Um Harba= is a conspicuous sandstone peak marked by a
triangulation beacon in latitude 23° 36′ 56″, longitude 34°
30′ 38″. Rising to a height of 688 metres above sea-level,
it forms the highest and central point of a long range running
north-north-west and south-south-east from the Wadi el Garara past
the Galt el Aguz. The north end of this range is forked, the east
and west arms being separated by a broad high valley, filled with
blown sand, draining from near the peak of Gebel Um Harba northwards
to Garara. A marked feature of the range is the almost constant
north-easterly dip of the sandstone beds of which it is composed;
the ridges follow the strike of the beds, and present gentle dip
slopes to the east with steep basset edges to the west. Gebel Um
Harba overlooks to the west a great sandy plain, so that it is a good
landmark for travellers coming from that direction. In occupying it as
a station, I approached it by the broad sandy valley above-mentioned,
and fixed the camp at 487 metres above sea-level and 800 metres
north of the summit; the hill can also be reached from the west,
though the climb from the plain is about one hundred metres more. The
ascent becomes rather steep near the top of the hill, but presents
no great difficulty. For a short time after rain, water can be found
in pools in the gullies close to the east of the hill, but owing to
the porosity of the rock these never last long. The Galt el Aguz,
nine and a half kilometres south-south-east of Gebel Um Harba, in a
gully on the east side of the road to Bir Abu Saafa, lasts longer
than other pools in the neighbourhood, but even it only yields
supplies within a few months at most after rain, for the same reason.
=Gebel Um Sididad= is a mass of high sandstone hills on the north side
of Wadi Silsila, thirty kilometres east-south-east of Gebel Um Harba
and overlooking the broad and sandy Wadi Naam to the east. The hill
I ascended, one of the highest, was 623 metres above sea-level and
nearly 300 metres above the plain at its foot. High sandstone hills
extend north-westwards from Gebel Um Sididad to Gebel Zergat Naam,
forming the western side of Wadi Naam.
=Gebel Abraq= is a great high sandstone plateau cut up by gullies
into more or less separate hills, outlined by the Wadis Silsila on
the north, Hodein on the south, Arned on the west, and Abraq on the
east. The highest hills of the mass are probably two peaks close
together on its east side, midway between Bir Abraq and the Wadi
Hodein, which rise to 705 and 699 metres above the sea. The principal
interest of Gebel Abraq lies in its forming a collecting ground for
the important springs of Abraq and Abu Saafa, which occur along its
eastern and southern feet. These springs yield constant supplies of
excellent water, due to slow percolation through almost pure siliceous
rocks, and are of great value both to the local Arabs and to the
passing travellers. There are two beacons on Gebel Abraq, one near
Bir Abraq and the other near Abu Saafa springs. The former, a main
triangulation point, is 667 metres above sea-level on a conspicuous
ridge in latitude 23° 25′ 19″, longitude 34° 46′ 48″; while
the latter is on the eastern edge of the plateau, in latitude 23°
18′ 40″, longitude 34° 48′ 30″, and 639 metres above the
sea. The eastern and southern slopes of the plateau are very steep,
becoming almost precipices at many points, and are the home of many
conies and rock partridges, but one can ascend by taking advantage of
the frequent gullies which cut up the mass. The climb to either beacon
from the plain is about 330 metres, and free from serious difficulty.
=Gebel Hodein= is a high sandstone plateau forming the south-east
continuation of the Abraq mass, from which it is separated by the
ravine of Wadi Hodein. To the south it is cut off by Wadi Dif. A
triangulation beacon near the north-east point of the plateau in
latitude 23° 16′ 20″, longitude 34° 53′ 25″, is 695 metres
above sea-level, but further west the summits are rather higher. An
extremely steep pass, practicable only on foot, exists to the south
of the mass, leading from the Wadi Gihab into Wadi Dif, and forming
a short cut from Abu Saafa Springs to Bir Dif, but camels have to
go round the east spurs of the mountain.
=Gebel Dif= and =Gebel Anfeib= together form a still further
continuation south-eastward of the same great sandstone plateau,
being separated from Gebel Hodein by the deep winding gorge of
Wadi Dif. The sandstone beds here dip to the north-east, and the
highest points are near the west edge of the mass, where they are
flanked by lines of lower hills, formed of schists cropping out
from under the sandstone. A triangulation beacon in latitude 23°
8′ 24″, longitude 34° 59′ 19″, marks the south end of the
high plateau of Gebel Anfeib; it is 705 metres above sea-level,
and very conspicuous from the east, but it is generally invisible
from the west side of the mass, owing to the ridges north-west of
it being slightly higher. In occupying the point as a station, I
approached it from Bir Dif, following up the Wadi Abu Hashim to its
head, then down the Rod Mukrayib round Gebel Lilowit, the south tip
of the schist range, and turning north across various small wadis
to a camp in one of the heads of Wadi Edunqul, at 315 metres above
sea-level and 1,200 metres south-east of the beacon. This camp could
also have been reached from Bir Abu Saafa via the Wadis Hodein and
Anfeib. The climb to the beacon, of 400 metres, is steep, but not
difficult, and occupies less than two hours.
=Gebel Tibatib= is a conspicuous dark conical peak among the low dark
hills which extend from Gebel Anfeib to Wadi Hodein. Its summit is
396 metres above sea-level.
=Gebel Butitelib= is a steep-sided little hill mass of grey felsite
close west of the easy pass which leads from the head of Wadi Abu
Hashim into the Rod Mukrayib, near the south end of Gebel Anfeib. It
rises to 485 metres above sea, or eighty metres above the sandy pass.
=Gebel Lilowit=, the south end of the schist range which flanks
Gebel Anfeib on the west, is 485 metres above the sea.
=Gebel Niqrub el Tahtani= is a conspicuous isolated jagged mountain
south of the Rod Mukrayib (which drains its northern face), and
west of Wadi Madi. The beacon on it is in latitude 23° 0′ 39″,
longitude 35° 0′ 53″, 829 metres above sea-level and about
500 metres above the Rod Mukrayib. A conspicuous pinnacle close
north-east of the beacon has practically the same altitude.
=Gebel Niqrub el Foqani= is a mountain of granite and felsite
rising to a height of 1,078 metres above the sea, from among the low
hill country which separates Wadis Madi and Gemal, in latitude 23°
52′. Its great height and isolated position render it a conspicuous
object in the landscape from great distances. It is drained by myriads
of small wadis radiating in all directions, but which all eventually
join Wadi Madi on the east or Wadi Gemal on the west. It is best
ascended from the west side, where a camp can be got 1,500 metres
due east of the beacon on the summit and 496 metres above sea-level,
in one of the stony heads of the channels draining towards Wadi
Gemal. The ascent from this camp occupied a little over two hours,
and was not very difficult; but an attempt from any other direction
would most likely have failed, as the slopes to the south and east are
extremely steep and in places precipitous. The top of the mountain
is a very rugged ridge, so broken that it is an hour’s hard work
to get along its 700 metres of length. The main ridge is surrounded
by lower flanking peaks on the north, east and south, while from
the west there runs off a long ridge, curving round to the south and
enclosing a small sandy plain south-west of the summit. This curved
ridge is cut through from east to west by a rather steep pass, 490
metres above sea-level. The view from the summit of Gebel Niqrub el
Foqani is very extensive, as will be seen from the panorama drawn to
scale from theodolite measurements on Plate XVI, but in the winter
months the mountain is frequently wrapped in clouds for days together;
I had to remain eight days on the summit in December 1907, before
I could complete my observations, most of the time being spent in a
cold wet mist which blotted out the landscape. The beacon on Gebel
Niqrub el Foqani, in latitude 22° 51′ 29″, longitude 34° 56′
49″, marks a point on the administrative boundary between Egypt
and the Sudan, the limit proceeding east-south-east to Bir Meneiga,
and south-south-west to Gebel Um el Tiur el Foqani.
The low hill country between Gebel Niqrub and Wadi Madi consists
chiefly of east and west ridges formed by dykes. A rather high granite
hill about ten kilometres to the south-east, close to Wadi Madi,
is marked by a beacon and overlooks the well called Bir Madi; the
beacon is 556 metres above sea-level, or eighty metres above the well.
To the south-west of Gebel Hodein the sandstone runs off in a mass
of very high hills called =Gebel Kala=, leaving a much lower area of
schist hills in between, through which the Wadi Feqoh pursues its
sandy barren course. Gebel Kala has not been closely approached,
but its principal peaks have been fixed by triangulation, and the
highest is 846 metres above sea-level. The scarps of these hills
are very steep, and the mass appears to be much cut up by wadis
draining to Feqoh. The sandstone ceases just beyond Gebel Kala,
and its place is taken by granite, which forms the mountains of the
watershed further south-west.
PLATE XVI.
[Illustration: MEASURED PANORAMAS FROM THE SUMMITS OF GEBELS NIQRUB
& GERF. (Plotted to scale from theodolite-observations & telescopic
sketches.)
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
=Gebel Um Reit= is a conspicuous granite mountain rising to 857
metres above sea, seventeen kilometres south-east of Gebel Awamtib,
on the east side of the watershed. It can be approached either from
the west by ascending the tributaries of Wadi Timsah and crossing
the watershed (which is here flat and sandy) into Wadi el Dreb,
or from the east by ascending the Wadi Um Reit. The best place from
which to ascend the mountain is in one of the heads of Wadi Um Reit,
which drains the west side of the mass. By following this up, a
camp can be placed about a kilometre north-west of the beacon and
520 metres above sea-level. The climb of 337 metres from the camp
is fairly easy, and only occupies about an hour. From the beacon
(latitude 23° 15′ 4″, longitude 34° 34′ 17″), a good view is
obtainable of the granite peaks to the south, which forms a complex
mass with Aqab el Negum as the highest point; to the eastward the
outlook is mostly over high broken sandstone plateaux.
Extending south-west from Um Reit is a complex of granite mountains,
which has not been surveyed in detail. The principal peaks have,
however, been fixed by triangulation, and their positions will be
found tabulated in the list of points given in Chapter III. The chief
peaks are =Gebels Etresia= (1,037 metres), =Um Markha=, =Shigigat=
(1,023 metres), =Hamrat el Feg=, =Aqab el Negum= (1,148 metres),
=Etus= (997 metres), and =Natetiai= (1,164 metres). An important
pass is said to cross the watershed at Aqab el Negum, though quite
practicable for camels, it is a very high pass, whence the name of
the mountain, which signifies “Pass of the Stars.” To the north
of Gebel Shigigat there is a sandy plain from which two conspicuous
isolated hills rise to heights of 901 and 703 metres respectively
above sea-level; these hills appear, however, not to bear any
distinctive names.
Further south along the watershed, in latitude 22° 50′, are two
conspicuous peaks of nearly equal height and not far apart, which
from the east look like two hop-kilns. These are called =Gebel
Sheyenit=. The southern one is the higher, rising to 887 metres
above sea-level, while the northern one attains 853 metres.
=Gebel Mishbih= is a huge bristling mass of granite peaks a little
east of the main watershed, rising from the plain west of Wadi
Feqoh in latitude 22° 44′. Being much higher than any other
mountain in the neighbourhood, it is a very remarkable feature for
long distances. Though it has not been surveyed in detail, its
chief peaks have been triangulated and the general shape of its
eastern parts is tolerably known by observations from Niqrub and
Korabkansi. The highest of its many peaks, near the south-west end
of the mass, reaches 1,353 metres, while the north-east peak, marked
by a beacon in latitude 22° 44′ 18″, longitude 34° 41′ 20″,
is 1,316 metres above the sea. The mountain is believed to be almost
entirely drained by feeders of the Wadi Feqoh.
=Gebel Shweib= is a smaller hill-mass a little to the south-east
of Gebel Mishbih. Its highest peak, which is at the north-east end,
is 914 metres above sea-level.
=Gebel Shabih= is a very remarkable granite mountain rising abruptly
from the sandy plain traversed by Wadi Feqoh in latitude 22° 45′,
about twelve kilometres east of Gebel Mishbih. From the north, it
looks like a very perfect cone, but as one passes it going south it is
seen to be slightly elongated meridionally, and to have two distinct
peaks, of which the northern and higher one rises to 1,117 metres,
or about 650 metres above the plain. Its sides are very steep, and
an ascent would probably be a matter of some difficulty. The Wadi
Feqoh passes close west of the mountain.
=Gebel Um el Kalala= is a small range of granite peaks close to the
east side of Wadi Feqoh in latitude 22° 50′. The peaks at its
north and south ends, nearly two kilometres apart, rise to 672 and
655 metres above sea respectively. In the low hilly country further
north there are three conspicuous little peaks of dark aspect rising
above the general level. =Gebel Mismih=, the highest of these, rises
to 599 metres above the sea; it is a nearly perfect cone twelve
kilometres north of Um el Kalala, and about six kilometres east of
Wadi Feqoh. =Gebel Waqif=, nine kilometres west-north-west of Um el
Kalala, is less sharp, and reaches 556 metres above the sea; while
the third hill, which is unnamed, lies nearly between the last two,
on the west side of Wadi Feqoh, and attains only 504 metres.
To the west of the Um Harba and Awamtib ranges there is open country,
formed by a great sandy plain, over which the Wadis Ghadrib and Timsah
pursue their northward courses to join Garara, and the monotony of
which is broken at intervals by extensive masses of moderately high
sandstone hills. The principal of these hill masses are Gebels Nuggur,
Mulgata, Ziraga, and the Abu Hashim Hills. =Gebel Nuggur=, marked
by a cairn, lies seventeen kilometres west of Um Harba, and a little
east of the Wadi Timsah; it forms a detached north-westerly extension
of Gebel Dagalai. =Gebel Mulgata= (545 metres) and =Gebel Ziraga=
(553 metres), both marked by triangulation cairns, are the chief
members of a long line of sandstone hills separating the Wadis Timsah
and Ghadrib. The =Abu Hashim Hills= extend for great distances south
and west of Bir Abu Hashim; the triangulation beacon on the hill west
of the well in latitude 23° 41′ 44″, longitude 34° 3′ 33″,
is 386 metres above sea, and sixty-six metres above the wadi floor,
but other hills of the group further south attain higher levels.
=Gebel Mowisat=, seventeen kilometres south of Gebel Ziraga and a
few kilometres west of the Wadi Timsah, is a granite hill capped by
sandstone. It is drained by the Wadi Mowisat. A track from Aswân
to Bir Um Reit passes a little north of this hill.
Round the heads of the Wadi Ghadrib, about the parallel of 23°
north and the meridian of 34° east, are numerous higher hills, of
which the principal are =Gebels Abu Rahia= (835 metres), =Romit=,
=Baid el Khuruf=, =Reietit= (825 metres), =Um Rewat=, =Um Ghalqa=,
and =Um Gotto=, while between these and Gebel Mowisat are the
=Hamiskul Hills=. These hills are all composed of granite, gneiss,
and schists, the higher ones, such as Abu Rahia and Reietit, having
sandstone capping the igneous and metamorphic rocks which build up
the main masses. Gebel Um Rewat forms the divide between the basins
of Wadi Kharit and Wadi Alaqi, its northern parts being drained by
the Wadi Reietit, a tributary of Ghadrib, while the south flanks
drain into the Wadi Um Ghalqa, a feeder of Wadi Seiga.
To the west of Gebel Mishbih there is hilly country, in which many
of the peaks reach considerable heights. The principal hill-masses
in this part are =Gebel el Naga=, a range about four kilometres long
running north-west and south-east, twenty-two kilometres west of Gebel
Mishbih, with several peaks, of which the highest is 827 metres above
sea; =Gebel Seiga=, a high hill (905 metres) about twenty kilometres
further west, surmounted by a triangulation beacon and drained by the
Wadi Seiga; =Gebel Nesheb Hasan= and =Gebel Abgeya=, two hills west
and south-west of Gebel Seiga, between Wadis Seiga and Abu Had; =Gebel
Um Krush=, between Wadis Abu Had and Um Ghalqa; =Gebels Ribdab=, =el
Deheis=, and =Abu Brush= (810 metres), to the west of Wadi Um Ghalqa;
and =Gebel Kulyeit=, a conspicuous cone about fifteen kilometres south
of Gebel Seiga, rising to 724 metres above sea. Most of these hills
are of schists, though Gebels Abu Brush and Ribdab are of granite.
=The Gerf — Korabkansi — Abu Hodeid Group.=
The central mountains of the Gerf — Korabkansi — Abu Hodeid group
form a compact cluster to the east of the main watershed between the
great eastward draining Wadis Hodein and Ibib. The most considerable
mass in extent is Gebel Gerf, an extremely rugged mountain tract
some twenty kilometres in diameter, having its highest point 1,419
metres above sea-level. The Abu Hodeid range, forming a southward
extension of the Gerf mass, attains the somewhat higher level of
1,488 metres; while the detached mass of Korabkansi on the west
rises to 1,230 metres. Besides these main masses, from which I have
named the group, there are numerous outlying ranges of lesser height,
the principal being the Beida range to the north, and the Hamra Dom
range to the east. The main characteristics of the central group are
its extreme ruggedness, the presence of great masses of serpentine
among its constituent rocks, and a relative abundance of good water
supplies. The wells and springs in the wadis draining from this
group of mountains are among the best and most permanent of the
water sources of the Eastern Desert of Egypt.
=Gebel Gerf= (_see_ map on Plate XVII) is a mass of rugged
mountains, roughly circular in plan, some twenty kilometres in
diameter, extending between latitudes 22° 35′ and 22° 50′,
and between longitudes 35° 8′ and 35° 20′. Its highest point,
marked by a beacon 1,419 metres above sea-level, is somewhat north
of the centre of the mass, being situated in latitude 22° 42′
6″ N., longitude 35° 12′ 16″ E. Approached from any side,
Gerf blocks out the entire view ahead. The central parts of the
mass are entirely impassable for camels. There is no possible track
across it from north to south, nor is there any east to west pass
across it north of the Sherefa Pass (which skirts its south end)
except by the heads of Wadi Shellal. The northern part of the mass,
which is semi-detached by the passes in the heads of Wadi Shellal
above-mentioned, is sometimes called =Gebel Meneiga= or =Gebel
Korbiai= after the important water sources of the same name in the
wadis draining from it; and the north-eastern peaks are sometimes
called =Gebel Muqur= from the spring Bir Muqur. But these names
are, I am told, quite local, and the entire mass is usually known
to the Arabs as Gebel Gerf. This application of a single name to an
entire group of mountains, with scores of separate peaks, extending
over about 500 square kilometres, is very unusual, especially when,
as in this case, it is drained by wadis containing good wells and
plenty of vegetation. The explanation given to me by the guides was
quite comprehensible; they stated that Gerf was the only mountain
mass in that part of the desert which was so extensive in every
direction as to prevent them getting a clear idea of its true shape
in their wanderings over it. They can get all round it only by a
rough journey of several days, and any endeavour to cross its main
portion met with failure, so that they had perforce to regard it as
a single great mass, of the true structure of which they could form
no satisfactory notion. The immense interest which the guides took
in the mapping of this particular mountain tract fully confirmed the
explanation given. The mapping was accomplished by making an entire
circuit of the mass, and ascending a few of the principal summits.
PLATE XVII.
[Illustration: MAP OF THE DISTRICT OF GEBEL GERF.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
The highest point of Gebel Gerf had been singled out as a
triangulation station from far to the north, while approaching the
mass from the Wadi Hodein. It was eventually reached from the west
side after leaving Gebel Korabkansi, the approach being made by
ascending the Wadi Eirahimib, and going over the pass at its head
(830 metres) into one of the heads of Wadi Um Reddam, turning round a
spur and ascending another of the heads of the same wadi. The camp,
placed as high up the wadi as possible, lay about 1,500 metres west
of the beacon, at an altitude of 820 metres. The climb of nearly
600 metres to the summit occupied three and a quarter hours, and
was free from serious difficulty, though involving some tiresome
traversing of connecting ridges. The summit of Gebel Gerf is often
wrapped in clouds for weeks together in winter, and cold northerly
gales are prevalent. I found it necessary to remain on the summit for
no less than twenty-one days and nights in January 1907, in order to
obtain the observations necessary, and the discomfort due to enforced
inaction and piercingly cold winds was considerable. The top of the
mountain is a narrow ridge on which there is barely standing room
for an instrument, but about 100 metres southward along the ridge
from the beacon there is a slight broadening where a small tent may
be pitched by hitching the ropes round rocks instead of tent-pegs.
On a clear day, the view from the summit of Gerf is a magnificent
one. The numberless rugged ridges and peaks of the Gerf mass itself
stretch for miles around, and out beyond, in every direction except
to the east, one can see the more distant mountains. In the north,
the most striking features are the distant spikes of Gebel Faraid,
and still further off one may discern the blunter forms of Gebels Abu
Gurdi, Hamata, and Abu Hamamid, 180 kilometres away. To the east is
the coast-plain, with the granite peaks of Gebel Hamra Dom breaking
the monotony. To the south-east one may see the great peaks of the
Elba and Shendib mountains, 130 kilometres away, though these are
often hidden by mist when everything else is clear. To the south,
one looks out, over the gneiss boss of Gebel Um Rasein, to the
mountains, rising rank behind rank, of Medarai, Abu Hodeid, Adar
Qaqa, and Is; while a little to the left of the last-named one may
see the double-headed granite mass of Gebel Obkeik in the Sudan,
more than 100 kilometres distant, towering above the intervening
Egyptian mountains. The panorama visible to the south and south-east
is shown drawn to scale from theodolite measurements in the lower
figure on Plate XVI (p. 206). To the south-west, one can make out
the principal mountains of the Alaqi basin, while to the west the
mountains of Korabkansi, Shabih, and Mishbih are conspicuous features.
The north portion of the Gerf mass, sometimes called Gebel Meneiga, is
drained by the Wadi Kreiga, which is a tributary of Wadi Hodein. One
of the principal feeders of Wadi Kreiga is the stony Wadi Meneiga,
important as containing perennial springs of good water, easily
accessible to camels. The eastern and southern parts of the mass
are drained by various feeders of Wadi Shab, the principal of these
feeders being Wadi Shellal el Sharqi, Wadi Muqur, Wadi Baaneit,
Wadi Diqdib, and Wadi Sherefa el Sharqi. The Wadis Muqur, Baaneit,
and Diqdib, all contain wells or springs, that in Wadi Diqdib being
right in the heart of the mountain mass, while the others are nearer
to its periphery. The western flanks of the Gerf mass are drained by
the feeders of Wadis Feqoh and Madi, the principal being the Wadis
Sherefa el Gharbi, Eirahimib, Shellal el Gharbi, and Korbiai. The
Wadi Sherefa el Gharbi is important as leading to the Sherefa Pass
(907 metres) which forms a direct road from Bir Sararat Seyet to the
well of Um Rasein, while Wadi Korbiai contains an excellent well at
its head, easily reached by camels.
=Gebel Dreb= is a many-peaked mass of mountains covering some sixty
square kilometres, situated south-west of the Gerf mass, from which
it is separated by the Sherefa Pass. Its highest peak is 1,293 metres
above sea, but there are numerous other peaks of but little inferior
altitude. Its south-western portion looks on to the plain at the head
of Wadi Feqoh, while to the south-east it is separated from Gebel
Medarai by an easy pass leading from the head of Kwat Hewah westwards
into the head of Wadi Kreim, a tributary of Wadi Feqoh. Another pass
is said to exist leading from Wadi Sherefa el Sharqi into the head
of Wadi Dreb, where there is a well called Bir Bint el Dreb.
=Gebel Medarai=, the next mountain mass to the south-east, is
separated from Gebel Dreb by the pass into Wadi Kreim above referred
to, while at its south faces it is separated from Gebel Abu Hireiq by
another pass leading from one of the heads of Wadi Medarai westwards
into the Wadi Kirwau, a tributary of Wadi Feqoh. The highest point
of Gebel Medarai, marked by a large cairn, is in latitude 22° 30′
58″, longitude 35° 12′ 5″, and rises to 1,299 metres above
sea-level. The north faces of the mass are drained by Kwat Hewah,
a tributary of Wadi Shab; the eastern flanks by Wadi Medarai, a
tributary of Wadi Ibib, while the western faces drain by various
feeders into Wadi Feqoh.
=Gebel Abu Hireiq=, the mountain-mass next south of Medarai,
extends eastwards, as a broad tract of many high ridges, almost to
the gneiss-boss of Um Rasein, while to the south it is united with
Gebel Abu Hodeid. The highest point of Abu Hireiq is 1,319 metres
above sea. Its eastern flanks are drained by tributaries of Wadi Ibib,
while the western parts drain into Wadi Feqoh.
=Gebel Abu Hodeid=, which forms a higher southward extension of Gebel
Abu Hireiq, is really two ranges with the Wadi Abu Hodeid draining
between them. The western range is the higher, its summit, marked
by a beacon in latitude 22° 23′ 18″, longitude 35° 14′ 9″,
being 1,482 metres above sea. The highest point of the eastern range
is 1,256 metres above sea. The south termination of this eastern
range is a very conspicuous rounded peak of granite, 992 metres
above sea, called =Abu Hodeid Ogla=, which forms a good landmark
for travellers in making the wells of Abu Hodeid; the wells lie
west of this peak. The south parts of the Abu Hodeid mountains are
drained by the Wadis Shinai, Delawet, and Abu Hodeid, all feeders
of Wadi Hasium, and all leading to important water sources. The
eastern faces are drained by Wadis Abu Hireiq and Tikraneib, which
are likewise feeders of Hasium, while the western flanks are drained
by feeders of Wadi Feqoh. The broad opening where Wadi Hasium passes
to the south of the range makes a natural division separating the
mountains of Abu Hodeid from those of the Adar Qaqa group.
=Gebel Mansur Diab=, a dark mountain, 1,091 metres high, lying six
kilometres west of Gebel Abu Hodeid, is not often visible from the
east, being hidden by the higher ranges in front of it; but it forms
a conspicuous landmark to any one approaching from the west.
To the south of Gebel Mansur Diab, between the heads of Wadi Feqoh
and Wadi Hasium, are some other mountains of considerable height, the
positions of whose summits were fixed by triangulation, but which were
not closely approached. These are =Gebel Hadal Derqa= (1,108 metres),
which as seen from the north appeared like a hog-backed dark ridge
with a conical semi-detached hill at its south-east end; and =Gebel
Hilwit Hasium=, which appeared to consist of two separate peaks
some three and a half kilometres apart, the higher or north-east one
rising to 1,037 metres, the south-west one to 952 metres above sea.
=Gebel Korabkansi= is a rugged mass of dark serpentine peaks and
ridges occupying a nearly isolated position some twenty kilometres
west of Gebel Gerf. Its highest point, marked by a triangulation
beacon, is situated in latitude 22° 39′ 16″, longitude 34° 59′
55″, and rises to 1,230 metres above sea. The main mass is flanked
by lower hills to the north and south, but is more open to the east
and west. It is drained entirely by feeders of Wadi Feqoh, the most
important of these being the Wadi Gemal. The upper portion of Wadi
Gemal is called Wadi Seyet, and is important as containing a well,
Bir Sararat Seyet; the well is about five kilometres north-east of the
main peak, at a place where the wadi cuts through the flanking hill
range. For the ascent of the mountain, it is best to turn westward
from near the well, and follow up one of the tributaries of Wadi Seyet
which leads right into the heart of the mountain; here a camp can be
pitched at 765 metres above sea-level, and the ascent of 465 metres
to the summit, from which there is a grand view, can be accomplished
in less than two hours. The ascent and descent require some care,
owing to the steepness of the slopes (the observed depression angle
from summit to camp was 29¼°) and the rottenness of the rock, which
comes away in lumps at a touch. The accumulated debris, consisting
of small fragments of serpentine, sets at just the angle of repose,
so that in coming down one can stick one’s feet firmly in the mass
and slide down with it for a hundred metres or more without exertion,
taking care only not to be shot over a sudden drop of the face. The
rocks are highly magnetic, and the compass is much disturbed anywhere
on or about the mountain. The mass of high hills which forms the
southward extension of Korabkansi, with peaks and ridges rising to
over 900 metres above sea-level, is called =Gebel Wadhait=. It is
drained on the north by Wadi Wadhait, a tributary of Wadi Seyet,
and on the west by the Wadi Kamoyib, a tributary of Wadi Feqoh.
=Gebel Um Rasein= is a triple-headed gneiss boss rising up boldly
among schists to the east of Gebel Medarai. Its remarkable form
and light colour render it a conspicuous feature to a traveller
approaching it from the north-east, and it is an important landmark
for the well, Bir Um Rasein, which exists in a small wadi at its
north foot. The highest peak of the three, marked by a triangulation
beacon in latitude 22° 28′ 12″, longitude 35° 20′ 19″,
is 909 metres above sea-level. For ascending the mountain, it is
best to follow up the Wadi Merdiyeb for a short distance on the
west side of the range, and a camp can be placed at 386 metres
above the sea in a small tributary gully which drains from the main
mountain. The climb of 523 metres to the beacon is steep in places,
but can be accomplished in two hours without difficulty by any one
used to negotiating smooth steep rocks. The top of the mountain is
more convenient for observation than most others in this region,
and there is a good view from it. The beacon is on a smooth hard
granite surface, with plenty of room to walk round an instrument,
while a little to the west there is a good place to pitch a small
tent, and a convenient cave for servants to sleep in.
=Kilia Arib=, another isolated granite mass about six kilometres
further east, rises to 647 metres above sea, and is a landmark for
the mouth of Wadi Diqdib, which contains a well.
To the east and south of Kilia Arib are some smaller granite hills
called Tibashoi. Though rising only some fifty or sixty metres
above the plain, these hills are conspicuous landmarks from their
isolated position. The northern, central, and southern ones are
called respectively =Tibashoi Dumat=, =Tibashoi Tumalhoi=, and
=Tibashoi Tomakolat=. Another hill of similar size and character,
five kilometres north-north-east of Kilia Arib, is called =Tuquqî=.
=Qrein Salama= is a little group of diorite hills rising from the
coast-plain to the east of Gebel Gerf. The highest hill of the group,
354 metres above sea, forms a conspicuous landmark which is visible
for long distances.
=Berget Abu Sarib= is a tract of low dark hills, with much drifted
sand, lying a few kilometres north-east of Qrein Salama.
=Gimeida=, a small but conspicuous black conical hill, rising to
sixty metres above the coast-plain, or 123 metres above sea-level,
is important as a landmark for ships entering Mersa Shab. A
triangulation beacon has been erected on the summit, the position of
which is latitude 22° 46′ 29″, longitude 35° 37′ 49″. The
azimuth from the beacon to the big tree at Mersa Shab is N. 62½°
E. A much lower dolerite ridge, two kilometres east of Gimeida,
is called =Umarawi=.
=Gebel Hamra Dom= is a range of remarkable red granite hills rising
abruptly from the coast-plain near latitude 22° 40′ and longitude
35° 40′. The range has a total length from north to south of
about eleven kilometres, the highest peak being near the centre of
the range. A beacon on this highest peak has the position latitude
22° 39′ 6″, longitude 35° 38′ 42″, altitude 389 metres
above sea. Care is necessary in sighting this peak, for there are
two others near it of nearly equal height; the beacon is on the
southernmost one of the three peaks near the centre of the range. A
pass leads across the range a kilometre south of the beacon. Gebel
Hamra Dom is a locality well known to the Arabs, in consequence of
its being occasionally favoured with some rainfall. In January 1907
the district round the mountain was covered with grass after a recent
fall of rain, but the hundreds of camels and other animals which the
Arabs took to graze at the place had eaten it all up when I arrived
there in February. At times of rainfall there is water to be got in
the sandy bed of a little wadi to the north of the beacon, at a place
called Ti Dabei Hamra Dom; but it does not last long after rain. Gebel
Hamra Dom is drained almost entirely by feeders of Wadi Ibib.
There are numerous smaller hills to the west of Gebel Hamra Dom, but
only the largest of them, =Tibansi Tikam Ankwei=, bears a special
name. This is a granite hill rising to 345 metres above sea-level,
situated eleven kilometres due west of the beacon on Gebel Hamra Dom.
=Gebel Khashab= and =Gebel Beidâ= together form a complex range
of high hills mostly composed of schists to the north of Gebel
Gerf. The range has its long axis north-west and south-east, with
a length of some twenty-five kilometres and an average breadth of
about eight kilometres. The highest point of the range is marked by a
triangulation beacon on Gebel Beidâ, 715 metres above sea-level, in
latitude 23° 0′ 14″, longitude 35° 16′ 54″. The north-west
part of the range is drained by the heads of Wadi Khashab, a tributary
of Wadi Hodein. The eastern faces are drained by the Wadi Beidâ and
various other feeders of Wadi Hodein, while the south and south-west
portions of the mass are drained by small tributaries of Wadi Kreiga,
itself a tributary of Wadi Hodein. So far as I know, the range can
only be crossed by camels at one place, near the centre of its length,
where it is cut through by the Wadi Beidâ; coming from the west,
one must make for the pass (395 metres above sea, stony but not
steep) which separates the heads of Wadi Khashab and Wadi Beidâ;
the road is well known as leading to the well called Bir Beidâ.
=Gebel Humariai= is an isolated hill, 563 metres above sea, a few
kilometres to the west of Gebel Beidâ.
=Gebel Kolaiqo= is a small hill-mass lying off the south-eastern
extremity of the Khashab — Beidâ range, from which it is separated
by the Wadi Kreiga. Its highest point, marked by a triangulation
beacon, is in latitude 22° 54′ 13″, longitude 35° 24′ 34″,
at an altitude of 320 metres above sea-level. The drainage is
mostly into Wadi Kreiga, but the south-eastern parts of the hills
drain into Wadi Kolaiqo, a very shallow ill-defined drainage line
coursing independently to sea across the sandy coast-plain. To the
north of Gebel Kolaiqo there are two long lines of low hills forming
low outliers of Nubian sandstone.
=Ti Qireira= is the name given to two low hills rising from the
coast-plain about half-way between Gebel Kolaiqo and the black conical
hill of Gemeida. These hills, four kilometres apart, rise only some
fifty or sixty metres above the plain, but they are conspicuous
landmarks, and hence bear a name.
=The Meisah — Adar Qaqa — Is Group.=
The Meisah — Adar Qaqa — Is group of mountains extends northwards
from the Sudan frontier in longitude 35½°. It is separated from
the Gerf — Abu Hodeid masses to the north by the Wadi Hasium; on
the east, the great Wadi Di-ib divides it from the mountains of the
Elba group; while to the west it is not sharply marked off from the
rather lower mountainous tract of the upper Alaqi basin. Gebels Adar
Qaqa (1,469 metres) and Is (1,736 metres) are on the main watershed,
while Hadal Aweib Meisah (1,224 metres) forms the highest point
of a huge rugged spur running northwards on the east side of the
watershed. To the east of the main mountains of the group, between
them and the Wadi Di-ib, are a number of detached mountain and
hill-masses, of which the principal are Gebels O Shakafa, Um Ein,
Qara Saba, Warabeit, Adar Aweib, and Shiab.
=Hadal Aweib Meisah= is a conspicuous double-topped mountain of
a somewhat conical shape. Its summit, marked by a triangulation
beacon, is 1,224 metres above sea-level, and has the position
latitude 22° 16′ 39″, longitude 35° 31′ 55″. In plan
it is almost circular, three-fourths of the circumference of its
base being formed by the Wadis Awitla and Lasewid (feeders of Wadi
Meisah), while the remaining fourth forms a connexion by which the
mountain is joined to the long ridge of Gebel Qidmib. The ascent of
the mountain was made from a camp one and three-quarter kilometres
due east of the summit, in a small feeder of Wadi Lasewid, close
to the spring called Megwel Um Edwa. Camels cannot get quite up to
the spring, but a camp can be placed a little way further down the
gully at an altitude of 596 metres above sea, and the climb of 628
metres to the top of the mountain is easily accomplished on foot in
about two hours. The mountain is composed of dark gabbroid rock, the
summit being composed of great blocks, weathered to a rusty brown on
their surfaces; the rock is highly magnetic, and the compass points
several degrees east of north at the beacon owing to local attraction.
PLATE XVIII.
[Illustration: MAP OF THE DISTRICT OF MEISAH & WADI DI-IB.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
=Iarih Meisah= is the name given to a tract of low granite hills with
sandy interspaces, which lies to the south of Hadal Aweib Meisah. It
forms the head of Wadi Baueiwai.
About three kilometres west of Hadal Aweib Meisah, a high ridge,
over 1,000 metres in height, courses north and south for over
fourteen kilometres. The north end of this ridge bifurcates to form
=Gebel Qidmib=; the Wadi Qidmib, draining northwards to Wadi Ibib,
has its head between the two branches of the ridge, where there is
a well called Bir Qidmib.
=O Shakafa= is a very remarkable hill seven kilometres north-east
of Hadal Aweib Meisah. O Shakafa derives its name, which signifies
“the barrier,” from the fact that it appears to block the way
to the traveller ascending the Wadi Meisah. Its crest, formed by
a ridge of hard jaspery quartzite, rises precipitously from among
a mass of softer rocks, some of which show remarkably brilliant
colours due to iron staining. The cairn on the summit is in latitude
22° 19′ 44″, longitude 35° 34′ 42″, and 751 metres above
sea-level. There is barely standing room on the top of the ridge,
which needs careful climbing owing to its precipitous nature. O
Shakafa is a good landmark for Bir Meisah, which lies in the wadi
about three kilometres north-east of the summit; and for the easy
pass of Sarob Kwan, which lies four kilometres to the south-east.
To the north of O Shakafa there extends a great tract of high hills,
divided into two portions by the northward-coursing Wadi Orgem. The
western portion of this hill-tract culminates in =Gebel Orgem=, the
two peaks of which rise respectively to 779 and 775 metres above the
sea, while its northern end forms the high sand-swathed hill called
=Baqari Daba=. The eastern portion of the tract, containing the
important wells Bir Um Bishtit and Bir Meisah, as well as the galts
of Meis-heit-ar, is rather more complex, and is cut into two parts by
the Wadi Um Bishtit. Its northern part ends in a conspicuous gneiss
hill called =Adar Aweib Um Bishtit=, while the hills immediately
north of O Shakafa are called =Gebel Meis-heit-ar=.
=Gebel Adar Qaqa= is a very conspicuous granite mountain about
twenty-three kilometres west of Hadal Aweib Meisah. Its highest peak
is in latitude 22° 13′ 47″, longitude 35° 19′ 0″, and rises
rather precipitously to 1,606 metres above sea-level. Adar Qaqa is
drained principally by the Wadi Hasium, which courses northward past
the western side of the mountain.
=Gebel Soaorib= is a rather long mountain range which adjoins
the south part of Adar Qaqa and sweeps round to the south-east,
forming the main watershed. Its highest point is 1,469 metres above
sea-level. Its north-western face is drained by Wadi Mantil Hasium,
which forms one of the heads of Wadi Hasium. The north-eastern flanks
are drained by the Wadi Haiyo and other feeders of Wadi Soaorib, while
the south-west faces drain into the Wadi Kirir and the Miti-Kwan,
tributaries of Wadi Alaqi.
=Gebel Leqaq= (1,192 metres) and =Gebel Um Seleim= (1,098 metres)
are two mountains, both with long northward spurs, lying north-east
of Adar Qaqa, between that mountain and the Wadi Soaorib. They
are drained by various feeders of the Wadis Hasium and Soaorib, the
principal being the Rod Anut Berer, which runs northward from between
two mountains to join Wadi Hasium, and the Wadi Hankuk, which rises
to the south of Gebel Leqaq and courses round the south-east flanks
to join Wadi Soaorib.
To the north of Gebels Leqaq and Um Seleim there stretches a sandy
plain, over which the Wadis Hasium, Ibib, and Soaorib pursue their
northward course. Low hills rise here and there from this plain,
the most conspicuous being =Gebel Hamra Tit=, a double-peaked granite
hill, rising to 642 metres above the sea; =Kulet Meigrum= and =Kulet
Tinasal= are two somewhat smaller hills situated respectively six
kilometres north-north-east and six kilometres east-north-east from
Gebel Hamra Tit.
=Gebel Is=, the next great mountain to the south, forms the main
watershed just north of the Sudan frontier, the triangulation cairn
on its summit having the position latitude 22° 2′ 36″, longitude
35° 28′ 4″, altitude 1,736 metres above sea. As seen from the
north, Gebel Is is a somewhat flat-topped mountain of dark aspect;
but judging by analogy the apparent flat top is probably only a
narrow ridge seen broadside on. From the main mass a long spur of
flanking mountains runs westward, and a high ridge, more or less
detached, rises to 1,474 metres six kilometres south-east of the
main summit. The northern and western faces of Gebel Is are drained
by feeders of Wadi Alaqi, while its eastern and southern parts are
drained by various heads of Wadi Is.
Between Hadal Aweib Meisah and Gebel Is there stretches a mass of
mountains with many peaks over 1,200 metres high; these appear to bear
no special names. My guides stated that there are two passes over
the main watershed in this region. The first, called =Adar Ameit=,
is a high pass practicable for camels; it lies about four kilometres
to the north of the beacon on Gebel Is, and connects the two Wadis
Adar Ameit el Sharqi and Adar Ameit el Gharbi which lie on opposite
sides of the watershed. The second pass, said to be a difficult one,
crosses the watershed some five kilometres further north, forming
a connexion between the heads of Miti Kwan and Wadi Soaorib.
=Gebel Miatit= (1,257 metres) and =Gebel Suruk= (1,377 metres),
are mountain masses a little east of, and semi-detached from, the
main Is group. Gebel Miatit sends out a long spur north-eastward,
ending in a rather conspicuous hill at the foot of which there is
said to be a water source called Megwel Aqwem.
=Gebel Shiab= is a collection of peaks rising from a rugged country
of lower hills about twenty-eight kilometres east of Gebel Is. Its
highest point is 987 metres above sea-level. Gebel Shiab appears
to form the main head of Wadi el Qurat, an important feeder of
Wadi Di-ib.
=Eqrun= (the horns) is a conspicuous group of schist hills lying
between the Wadis Meisah and Ibib. It has two principal peaks; the
higher one, surmounted by a triangulation beacon, has the position
latitude 22° 30′ 10″, longitude 35° 37′ 9″, and is 473
metres above sea-level; the other is about 400 metres south-east
of the beacon, and is only five metres lower. Eqrun itself is an
isolated hill group, but close to the north-east of it there is
another hill-mass of greater extent and of but little inferior height.
The country south of Eqrun forms an extensive tract of low hills
with much blown sand. Two conspicuous hills in this tract rise above
the rest and bear special names; these are =Tahaqayet= (432 metres)
and =Titailibab= (593 metres).
=Kolmanab= and =Einiwai= are two small but very conspicuous black
hills eleven kilometres apart, rising from the sandy coast-plain
between the Wadis Meisah and Di-ib. Both are surmounted by
triangulation beacons, that on Kolmanab being in latitude 22° 32′
26″, longitude 35° 53′ 36″, 137 metres above sea, and that
on Einiwai being in latitude 22° 27′ 50″, longitude 35° 57′
59″, 138 metres above sea. North-west of Kolmanab are some low
banks called =Tinadei=, while about mid-way between Kolmanab and
Einiwai is an isolated low hill called =Ankalidot=.
=Osnei= is a small but conspicuous red granite hill, rising to 251
metres above sea, thirteen kilometres west-south-west from Einiwai. It
contains a galt, which yields water for some little time after rain
has fallen locally.
=Ti Keferiai= is a conspicuous little isolated group of dark hills
of no very great height, situated in the fork where the Wadis
Didaut and Baueiwai join to form the Wad el Qireira. There are
heavy accumulations of blown sand round the north-east flanks of
the mass. The triangulation beacon on the summit has the position
latitude 22° 21′ 0″, longitude 35° 49′ 47″, and is 494
metres above sea-level. Ti Keferiai forms a good landmark for the old
mines of Romit, which are situated in some lower hills five kilometres
south-west of the beacon. There are numerous excavations here in
veins of smoky quartz with calcite and chalybite, which penetrate
the country rock of highly crushed and decomposed diorite; a number
of ancient grinding mills of diorite lie scattered about the place.
Four kilometres north of Ti Keferiai, on the opposite side of Wadi
Didaut, is a conspicuous hill of very red granite called =Adatalob
Adara=, 385 metres above sea-level. Four kilometres further north-west
is another hill, of nearly equal height, but of black aspect, called
=Adatalob Hadal=. West of Ti Keferiai, at distances of five and a
half and nine and a half kilometres respectively, are two conspicuous
little hills rising from the plain, one on either side of the Wadi
Didaut; these are called =Kikeiyet Sharqi= and =Kikeiyet Gharbi=.
East of Ti Keferiai is a great sandy tract stretching to the
Wadi Di-ib, from which low hills rise half swathed in blown sand;
the principal hill groups bear the names of =Gebels Tishushi= and
=Tishushi Tiboki=.
=Qara Saba= is a high and steep hill mass of dark aspect, rising
conspicuously to 788 metres above sea, between the Wadis Didaut and
Baueiwai, some sixteen kilometres south-west of Ti Keferiai. The
tract between Qara Saba and Ti Keferiai is a waste of blown sand
through which low hills protrude in places.
=Adar Aqdeib=, a granite hill 736 metres high on the north side of
the Wadi Didaut, about half-way between Qara Saba and O Shakafa, is a
landmark for two small water sources and a pass. The first of these
water sources, Megwel Adar Aqdeib, is on the east side of the hill,
in a little tributary of Wadi Didaut. The second, Megwel Didaut, is
at the head of Wadi Didaut itself, in a separate rugged hill tract
south of Adar Aqdeib. The west faces of Adar Aqdeib are drained by
the Sarob Kwan, half of which courses south-east to Wadi Didaut,
and half north-west to Wadi Meisah, and the divide forms a well
known easy pass.
=Gebel Um Ein= is a huge hill-mass of dark rocks, rising to 901
metres above sea-level, nine kilometres south-south-west of Qara
Saba. The beacon which marks the summit is in latitude 22° 11′
52″, longitude 35° 39′ 4″. Gebel Um Ein is mainly drained
by the Wadi Baueiwai, which curves round the south half of its
circumference. A small water source, Megwel Um Ein, is said to exist
on the north-east side of the hill, in a small wadi which forms a
tributary of Wadi Baueiwai.
A great tract of high hills lies between the Wadis Baueiwai and
Di-ib. The northern part of the tract, which is cut off from the
rest by the Wadi Warabeit, and is called =Gebel Geror=, has several
peaks rising to over 500 metres; on the north it is flanked by huge
accumulations of blown sand, while its southern faces are drained
by fairly well-wooded wadis, tributaries of Wadi Warabeit. The
part of the hill tract south of the Wadi Baueiwai is much cut up by
wadis into masses which bear separate names. =Gebel Hamida=, which
with =Gebel Nubitra= forms the westernmost hill-mass of the group,
is a series of high steep schist ridges rising in places over 700
metres above sea-level. The highest point, 754 metres above sea,
is best reached by following up the Wadi Hamida till one comes due
west of the hill, and then striking up eastwards on foot; it can
also be reached from the east side _via_ the tiny trickling salt
spring of Megwel Hamida, but I found this a long and wearisome
climb. To the north-east of Gebel Hamida is the pass called Bani
Sana, which is important both as a pass and as being the boundary
between the territories of the Kurbeilab and Hamedorab Arabs. =Gebel
Warabeit=, the part of the tract which forms the head of the Wadi
Warabeit, lies south-east of Gebel Hamida, being connected with
Gebel Hamida on the one side and Gebel Mashushenai on the other;
its highest point is 794 metres above sea-level. =Gebel Mashushenai=
(634 metres) lies a little to the east of Gebel Warabeit; its north
parts are drained by the Wadi Hashimaiyib, while the south portions
are drained by Wadi Mashushenai, in the head of which is a well,
Bir Mashushenai. All the drainage from hereabouts ultimately reaches
Wadi Di-ib by way of Wadi el Qurat. =Adar Aweib=, a conspicuous and
extensive granite hill-mass lying east of the foregoing, from which
it is entirely separated by wadis, rises to 620 metres above sea;
its summit is marked by a triangulation beacon in latitude 22°
10′ 50″, longitude 35° 54′ 0″. In occupying Adar Aweib as
a station, it was approached from the Bani Sana pass by following
down the Wadi Warabeit and then turning up the Wadi Wieqwer, which
leads to the eastern foot of the mountain. The camp was placed
about a kilometre north-west of the beacon, at an altitude of 284
metres above sea, and the climb of 336 metres to the top took only
an hour and a half. A great variety of flowers could be gathered
in the lower part of the ascent; the upper portion was slippery,
the slopes consisting of debris of decomposed granite resting just
at the angle of repose. In descending from the mountain, I went
northwards on foot, whence a steep pass led down to Bir Meheriqa,
in the Wadi Di-ib; but the camels had to go round the south end of
the mountain by Wadi el Qurat, as the pass was too steep for them.
To the south of the group of hills just described, there is a rugged
tract of low hills stretching away south to Gebel Shiab. Eastwards
this tract becomes lower and more sandy, terminating in a sandy plain
with low rocky ridges, over which the Wadi Di-ib pursues its northward
course, becoming closed in again by hills abreast of Adar Aweib.
=The Mountains of the Alaqi Basin West of Adar Qaqa.=
The mountains of this group, which are scattered over an area of
some 5,000 square kilometres between latitudes 22° 0′ and 22°
22′, and longitudes 34° 0′ and 35° 20′, are comparatively
little known. The positions and heights of all the principal peaks
have been fixed by triangulation from considerable distances; but
with the single exception of Gebel Muqsim, which was occupied by
Mr. Villiers Stuart as his terminal point, none of the area has yet
been officially surveyed.
The positions determined for the principal peaks will be found
included in the list on pp. 51 to 64, and a general idea of the
relative positions of the mountains and drainage lines will be
obtained from the orographical map on Plate I. A brief reference
only to the principal mountains is possible here.
=Gebel Anweiyib= (921 metres) and =Eir Arib= (1,112 metres) are on
the main watershed. As seen from the north, the former appeared as
a long dark range, the latter as a light-coloured high short ridge
with a peak at its western end.
=Gebels Duag= (1,328 metres) and =Himeitra= (1,231 metres)
are connected with the watershed range of Adar Qaqa and Is by
westward-running spurs. Gebel Himeitra is a landmark for a well,
Bir Himeitra, which is situated a little south of the mountain,
and also for the ruins of Darahib, which lie in the Wadi Alaqi some
twelve kilometres south-south-west of it.
=Gebel Heianai= (1,256 metres) is a long range of mountains between
the Wadis Bint el Feqoh and Defeit.
=Gebel Heleikonti= (1,151 metres) appeared from the north as a short
high steep ridge with a little peak at its western end.
=Gebel Egat=, one of the best known and most remarkable of the
mountains of the group, is a high steep cone rising to 1,145 metres
above sea on the north side of the Wadi Alaqi in latitude 22° 5′
39″, longitude 34° 52′ 15″. It is a landmark for Bir Egat,
which lies about five kilometres to the east, and for the mines of
Alfawi, which lie some ten kilometres south-east of the peak.
=Gebel Shanaiyet= (907 metres) and =Gebel Hamida= lie south of the
Wadi Defeit, between that wadi and the Wadi Egat.
=Gebel Hateib= or =Suhin= (854 metres) forms the main collecting
ground for the Wadis Hateib and Suhin, which are tributaries of Alaqi.
=Gebel Um el Tiur el Foqani= is a group of very high steep hills
on the south side of Wadi Defeit. It has a well-marked peak as its
summit, in latitude 22° 17′ 56″, longitude 34° 41′ 14″, 946
metres above sea-level. This peak forms a point on the administrative
boundary between Egypt and the Sudan.
=Gebel Um el Tiur el Tahtani=, situated some twelve kilometres
west-north-west of the foregoing, and on the opposite side of the
Wadi Defeit, is a somewhat similar but lower group of hills, its
highest point rising to 783 metres above sea.
=Gebel el Adraq= (770 metres) and =Gebel Guqub= are two other
hill-groups south of Gebel Um el Tiur el Tahtani, lying between
the Wadis Defeit and Alaqi. Gebel el Adraq is a landmark for some
old mines called Betan, while Gebel Guqub is the collecting ground,
the drainage of which supplies the important well of Bir Guqub.
=Gebel Muqsim= is a conspicuous mountain on the south side of the
Wadi Alaqi near the meridian of 34°. The triangulation cairn on its
summit is in latitude 22° 10′ 11″, longitude 34° 1′ 12″,
at an altitude of 825 metres above sea-level. Gebel Muqsim forms a
point on the administrative boundary between Egypt and the Sudan.
=The Elba-Shendib Group.=
This group of granite mountains is situated near the sea in the
extreme south-east corner of Egypt, between longitudes 36° and 37°,
on and about the parallel of 22° of north latitude. Part of the
group, including the highest peak (Asotriba, 2,216 metres) is in the
Sudan, and we shall here consider only the northern parts, which fall
within Egypt proper. The principal mountains of the group are Gebels
Elba (1,428 metres), Shendib (1,912 metres), Hanquf (1,465 metres),
Shendodai (1,529 metres), and Shellal (1,409 metres). Besides these,
which form a cluster of high rugged ridges and bristling peaks, there
are some outlying hills to the east and west, and it is convenient
to consider all the hills east of Wadi Di-ib as belonging to the
group. The principal of these outlying hills are Gebels Balatitda,
Sul Hamid (572 metres), Qash Amir (724 metres), and Sela (560 metres)
on the west, and Karam Elba (586 metres) and Gebel Hadarba (217
metres) on the east of the main masses. The general relations of
the Elba district will be seen from the orographical map on Plate I,
while the large scale map on Plate XIX shows the detailed features
on a larger scale.
Towering to great heights from the coast-plain, the mountains of
the Elba group are very conspicuous from long distances either on
sea or on land when the air is clear. But often for weeks together
they are so shrouded in mist as to be invisible even when one is
fairly near to them. These very mists, which so often hinder the
view being obtained, are the cause of much added beauty to the scene
when the air is clear; for the moisture produces a rich vegetation,
not only in the wadis, but along all clefts right up to the tops
of the mountains, and furnishes in addition the largest and most
important water sources in the Eastern Desert. So abundant is the
vegetation in all the wadis draining from Elba, that it is impossible
to approach the mountains very closely with loaded camels, owing to
the closeness of the trees. Richest in water supply and in vegetation
of all tracts in the Eastern Desert of Egypt, it is natural that the
Elba district should also be the greatest centre of desert population,
and there are considerable settlements of Bisharin Arabs round the
feet of the mountains.
PLATE XIX.
[Illustration: MAP OF THE DISTRICT OF ELBA & HALAIB.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
=Gebel Elba=,[111] the most northerly mountain of the main group,
is cut off from the mountains to the south by the Wadis O Sir Hadal
and Serimtai; there is a pass between the heads of these wadis,
so that a complete circuit of the mountain can be made, although
from almost any aspect Elba appears to be joined on to the other
mountains of the group. In plan, Gebel Elba is nearly a square of
about fifteen kilometres sides, with its diagonal in the meridian. It
is a bristling mass of light-coloured granite peaks, flanked on the
south and west by rugged hills of darker rocks. The highest point,
the “high peak” of the Admiralty Chart, is in latitude 22°
10′ 3″, longitude 36° 21′ 52″, and 1,435 metres above sea;
another peak, slightly lower, but more conspicuous and nearer the
centre of the mass, was chosen for the site of the triangulation
station. The beacon on this latter peak is 1,428 metres above sea,
and has the position latitude 22° 11′ 27″, longitude 36°
20′ 52″. The peak which bears the triangulation station forms
a centre from which drainage lines radiate in all directions. The
principal of these drainage lines, which are all well wooded, are
the Wadi Yahameib, which with its feeders Wadis Akau and Kansisrob
drains the north faces of the mountain, and unites with Wadi Aideib,
which drains the north-east flanks; Wadi Serimtai, which by its
feeder the Wadi O Sir Eirab drains the south part of the mass and
then curves round north-eastwards to the sea; and the Wadi Yoider,
which drains the western parts of the mountain by its three main
heads called respectively Wadi Akwamtra, Wadi Qeirat, and Wadi O
Sir Hadal, and then courses northward to reach the sea.
The approach to Gebel Elba by the coast-plain from the north-west is
said to be difficult, on account of having to cross an extensive tract
of sand dunes, called I Hubal, which lies to the north and north-east
of Gebel Sul Hamid. The survey expedition reached the mountain
by marching eastward from Bir Meheriqa in the Wadi Di-ib. On this
road the sand was not found a serious hindrance, though progress was
rather slow through O Harbub, a sand-choked wadi which was entered on
turning eastwards just after leaving Bir Meheriqa. Skirting the south
side of Gebel Sul Hamid over a sandy plain, we continued eastward
with a slight northerly bend till the jagged mass of Qash Amir came
into view; then striking due east again we entered some low hills
and dropped by an easy pass into Wadi Siamtit, a little feeder of
Wadi Yoider; crossing the main channel of Yoider, we continued our
course eastward across very sandy minor wadis, and turning a little
southward we reached Bir Akwamtra, where we found a fairly large
Bisharin camp, in a stony wadi full of trees.
I had hoped to ascend the mountain by way of Wadi Akwamtra, which
heads right under the peak selected for the triangulation station. But
on arriving at the well we were still more than six kilometres
from the head of the wadi, and further progress for camels was very
difficult owing to the closeness of the trees, and the bouldery nature
of the wadi floor. Guides sent out to reconnoitre having reported that
the ascent could be made with less difficulty from the Wadi Yahameib,
we followed a very winding track leading over the Asut Duk pass into
Yahameib, and then made our way southward over the sloping bouldery
plain, thick with trees and scrub, until the camels could get no
farther. The camp was pitched in a slight clearing at the foot of the
mountain, three and a quarter kilometres north-west of the beacon, at
an altitude of 343 metres above sea, or 1,085 metres below the beacon.
The climb to the summit was a long and tiring one, but very
interesting. Starting at 6.30 a.m. on April 25, 1908, we first
followed up the Wadi Yahameib to its head in a sort of neck
between two peaks; this neck, which we reached at 10 a.m., is
1,093 metres above sea. About half way up to the neck, among some
large granite blocks, there is a small spring of very pure water;
it forms a pool holding about a gallon and a half, which fills as
fast as it is emptied. Passing over the neck, we dropped down to a
level of 984 metres in crossing the head of Wadi Akwamtra, and then,
climbing up the opposite side, we reached the beacon (1,428 metres)
at noon. Except the last 150 metres to the summit, which was bare
steep granite, the whole climb was through a thick growth of trees,
very green and fresh, with a tangled undergrowth of flowering shrubs
and some mosses and lichens. The trees grow very near to the summit
and give plenty of shady resting-places. Acacia (_sellim_) trees cease
about 350 metres above sea, and new forms take their place. The most
remarkable is a large tree called _Hohait_ by my Arabs; this tree,
which I have not seen elsewhere in Egypt, grows in fair abundance to
ten metres or more high, with thick woody looking trunk and branches,
the foliage being great bunches of aloe-like leaves on the ends
of the branches; according to my Arabs, it bears an edible fruit,
of which they showed me the stone—a nearly spherical red one,
about as big as a pea, very hard.[112]
The top of the mountain is narrow and very rough, but narrow sleeping
places can be found on ledges. The view from the summit in clear
weather is very fine and extensive; the subjoined figure is from
a careful sketch which I made of the outlook southwards from the
beacon. But, as already remarked, the mountain is frequently shrouded
in cloud, and of the ten days I remained on the summit in April and
May 1908 only three were clear.
[Illustration: Fig. 3.—View from the summit of Gebel Elba.]
The phenomenon of “glories,” or rainbow-coloured rings round the
shadow of one’s head cast on to clouds below when the summit was
clear, was well observed in the mornings. Three rings were specially
distinct and vividly coloured on April 26, and I was able to measure
the diameters with an improvised subtense apparatus; measuring to
the middle of the yellow in each case, I found the diameters of the
rings to be 4½°, 8¾°, and 13°, so that the diameters increase in
arithmetical progression. The shadow cast by one’s head and body
was most distinct when the cloud-bank was most opaque; the rings,
on the other hand, were most brilliant when there was only a thin
film of cloud.
The temperatures experienced on the summit were remarkable for their
range. On April 25, 26, and 27, 1908, the air was still and full
of wet mist, and the days were oppressively hot, while the nights
were also warm and damp. On April 28, a cold north-west wind set
in, which soon cleared the air; but with the clearness came such
a chilling of the air that it was impossible to stand up to the
instruments for observations for more than a few minutes at a time;
one was glad to take shelter behind rocks from the biting blast,
and though we were well within the tropics and the spring was far
advanced, we sat shivering with blankets round us even in the sunniest
and most sheltered spots we could find. The cold lasted till May 4,
when we descended the mountain to be half roasted in the plains below.
As already remarked, Gebel Elba is well supplied with water
sources. The two chief are Bir Akwamtra and Bir Kansisrob, both
situated on the north side of the mountain. Between them is a small
spring called Megwel Akau. On the south side of the mountain are two
other wells called Bir Salalat O Sir, and Bir Sararat Serimtai. In
times of rainfall there must be scores of rock pools along every
drainage line.
=Karam Elba= is a granite hill rising to 586 metres above sea, close
to the north-east foot of Gebel Elba, from which it is separated
by a narrow wadi. Close north of Karam Elba are some low granite
hills called =Takrat Riba=, while on the south side is another small
granite hill called =Mikeriba=.
To the east of Karam Elba are some granite hills which, though of
no great height, are conspicuous owing to their position on the
coast-plain, and being used as landmarks by the local Arabs they
bear special names. These are: =Alafot=, =Taar Ara=, =Kreishim=,
=Abai Sis=, and =O Wota=, the last-named being the largest of them
all. Some low banks north of Alafot are called =Alafot Onqwab=.
=Qash Amir= (“Scragged Hill” of the Admiralty Charts) is
an isolated hill rising abruptly from a sandy plain at the head
of Wadi Eikwan, about fifteen kilometres west-north-west of Gebel
Elba. Qash Amir well deserves the title given to it by the Admiralty
surveyors, for it is a mass of sharp granite spikes which my best
guides, skilled climbers though they were, could only ascend with
the greatest difficulty. Its top, marked by a beacon, is 724 metres
above sea-level and has the position latitude 22° 14′ 31″,
longitude 36° 12′ 20″. I had intended to occupy the summit as
a main station, but the guides who were sent to erect the beacon
reported that the summit was so sharp a spike that there was barely
room for a beacon to be built, and that it would be impossible to set
up a theodolite tripod on it, while there was not even a narrow ledge
where one could sleep within several hundred metres of the summit.
=Gebel el Sela= is a straggling group of high rugged granite hills
rising from the sandy plain to the north-east of Qash Amir. The
highest of its peaks reaches to 560 metres above sea-level.
=Gebel Sul Hamid= is an extensive tract of low dark hills, covering
some hundred square kilometres or so to the west of Qash Amir. Its
highest peak is 572 metres above sea. The north part of the tract
is drained by the Wadi Di-it, the eastern part by the Wadi Eikwan,
while the southern drainages pass into a very shallow channel which
courses westward over a sandy plain towards Wadi Di-ib, but becomes
choked with sand at O Harbub before reaching that great trunk wadi.
=Gebel Balatitda= is a group of high hills lying between Gebel Sul
Hamid and the Wadi Di-ib. Its highest point is 592 metres above
sea-level. Bir Meheriqa is situated at the south-west of the mass,
on the east side of Wadi Di-ib. The north flanks of Gebel Balatitda
are swathed in blown sand.
=Gebel O Sir Eirab= is really the south part of Gebel Elba; its
highest point is 842 metres above sea. Though its name Eirab means
“white,” the mountain is composed of dark-coloured rocks. The
explanation is that the Arabs always give the names to the wadis
first, and the adjacent Wadi O Sir Eirab has a white sandy floor
because it drains from the granite mass of Elba; the mountain is
called after the wadi near it.
=Gebel Hanquf= is a range of mountains some twenty kilometres in
length, stretching in a south-easterly direction to the south of
Gebel Elba and separating that mountain from Gebel Shendib. Its
south-eastern portion, containing the highest peaks, is of granite,
while the north-western portion consists of dark rocks. Its highest
point is the northerly one of two remarkable peaks near the south end
of the range, and rises to 1,465 metres, while another summit near
the middle of the range reaches 1,397 metres. The northern part of
Gebel Hanquf is drained by the Wadi O Sir Hadal, a tributary of Wadi
Yoider; its eastern flanks by the Wadi Serimtai; while the western
drainage is to the Wadi Hareitra, which courses from between Gebel
Hanquf and Gebel Shendib westwards to join the Wadi Di-ib.
=Gebel Shendib=, which lies close south-west of Gebel Hanquf, is a
great mass of very high light-coloured peaks flanked on the west by
a tract of moderately high hills of dark colour. The beacon which
marks the highest point, 1,912 metres above sea, is in latitude 22°
0′ 48″, longitude 36° 16′ 30″. Shendib is the third highest
mountain in Egypt proper, being surpassed in altitude only by El
Shayeb and Hamata. Besides the main peak, there are numerous others
exceeding 1,600 metres in height; one of these, some two kilometres
south-east of the principal summit, reaches to 1,863 metres and marks
very nearly the Sudan frontier; its latitude is 21° 59′ 56″,
so that it is only some 120 metres south of the 22nd parallel.
The north portion of Shendib is drained by the Wadi Hareitra,
the south part by Wadi Shendib, both these being tributaries of
Wadi Di-ib.
=Gebel Shendodai= (“Castle Hill” of the Admiralty Charts) is
a high mountain mass lying east of Gebel Hanquf, from which it is
separated by the Wadi Serimtai. Its highest point, a well-marked peak,
is in latitude 22° 3′ 1″, longitude 36° 25′ 31″, and rises
to 1,529 metres above sea-level. Gebel Shendodai is drained by the
Wadis Um Seyal (a tributary of Wadi Serimtai), Mera Kwan, and Shellal.
=Gebel Shellal=, situated close south-east of Gebel Shendodai
on the Sudan frontier, is a group of mountains of slightly lower
altitude than the foregoing, its highest peak being 1,409 metres above
sea-level. Gebel Shellal is drained by the Wadis Shellal and Aqilhoq,
the latter containing a good well, called Bir Frukit. A tract of low
foot-hills, some twelve kilometres broad, fronts Gebels Shendodai
and Shellal seawards, leaving a breadth of some twelve kilometres
of gently sloping coast-plain between them and the shore. One of
the foot-hills of Gebel Shellal, a conspicuous high dark-coloured
ridge near Bir Frukit, bears the name of =Gebel Balatitda=. (It
will be noticed that another hill group west of Gebel Elba bears
the same name).
=Gebel Hadarba= is a little range of felsite hills with many peaks
rising from the coast-plain close to Ras Hadarba (Cape Elba of the
Admiralty Charts). A triangulation beacon on one of the highest points
is in latitude 22° 2′ 53″, longitude 36° 47′ 23″, at an
altitude of 217 metres above sea. Gebel Hadarba is drained by a number
of small wadis, most of which empty themselves into the quicksands
of Kuatianai which cover the projection of Cape Elba. A high hill at
the south-west end of the Hadarba range bears the special name of
=Wiekorei=, while a tract of low red hills on the Sudan frontier a
few kilometres south of the Hadarba range, is called =Timaiakwaia=;
this latter tract is chiefly drained by the Wadi Qabatit.
* * * * *
[Footnote 106: The exception is El Shayeb, in latitude 26° 58′,
which attains a height of 2,184 metres. _See_ BARRON and HUME,
Topog. and Geology of the Eastern Desert of Egypt (Central
Portion). Cairo, 1902. p. 40.]
[Footnote 107: Each of the last three vowels is pronounced
separately, so that the word has four syllables, with the accent on
the penultimate.]
[Footnote 108: The position of this cairn is latitude 23° 57′
46″, longitude 35° 12′ 10″.]
[Footnote 109: The position of the cairn is latitude 24° 4′ 41″,
longitude 35° 15′ 34″.]
[Footnote 110: By measurement with the theodolite I found the average
slopes of the mountain to be 35°, and many parts have double this
inclination. The vertical angle from my camp to the summit was
over 23°.]
[Footnote 111: The word _Elba_ (Bishari) means “white mountain.”
The designation “Gebel” is thus strictly speaking superfluous,
but is convenient as the Bishari tongue is so little known.]
[Footnote 112: Prof. Schweinfurth informs me that the tree is the
dragon’s-blood tree, _Dracaena ombet_ v. _Heuglin_; he himself
did not see it in the Elba neighbourhood, and its occurrence has
not hitherto been recorded further north than the Erkowit district
of the Sudan (latitude about 19°), where the native name for the
tree is _to-omba_ or _t’ombet_. See _Bollettino della Società
Africana d’Italia_: Naples, 1891.]
CHAPTER VII.
* * * * *
=WATER SUPPLIES.[113]=
* * * * *
The sources of water in South-Eastern Egypt, as in the Egyptian
deserts generally, may be divided into three main classes:—
(1) Springs;
(2) Wells;
(3) Rock basins.
=Springs.=
As springs are classified those water sources where water issues
naturally from the rocks, either above or near ground level, without
the aid of artificial excavation. As will be seen on looking through
the list of water sources on pp. 244 to 250, springs are less common
than wells and rock basins, but some of the best known water sources,
such as those of Abraq, Abu Saafa, Abu Hodeid, and Meneiga, belong
to this class. The Arabic word for spring is _Ain_, but the Bedouin
seldom use this word, calling springs and wells alike _Bir_, which
properly signifies a well. Small springs are called _Megal_ by the
Ababda, and _Megwel_ by the Bisharin tribes.
Springs may occur in any kind of rock, but the rock must be either
of a porous nature or must contain fissures. Thus the springs of
Abu Saafa and Abraq occur in sandstone, which is itself porous and
permits the passage of water through the body of the rock, while the
springs of Meneiga occur in a crushed serpentine, which, though not
itself a porous rock, is full of fissures and crush-planes, and thus
is capable of holding and giving passage to underground waters. It
is in consequence of the non-porosity and the comparative fewness
of fissures in granitic rocks that springs are seldom seen to issue
from rocks of this class.
The collecting areas of the Eastern Desert springs are mostly
in the immediate neighbourhood of the springs themselves. Thus,
for instance, the springs of Abu Saafa and Abraq are fed by the
rainfall on the great sandstone plateaux which surround them, while
those of Meneiga are supplied by the rainfall on the mountain mass
of Gebel Gerf. In consequence of the fact that the waters do not
travel very far underground before they issue from the springs, the
water is generally cool. The yield of the springs is usually small,
rarely exceeding ten litres a minute from any individual spring, but
it is wonderfully constant; the rocks of the collecting area form a
huge reservoir which only parts slowly with its water contents, and
thus springs may go on yielding supplies when, after a succession
of three or four nearly rainless years, many of the wells and rock
basins are quite dry.
As a rule, spring waters are very clear and potable. The purest are
those which pass through siliceous rocks such as sandstone; where
the rocks are rich in lime and magnesia, as serpentines and gabbros,
the salt-content of the spring may be fairly considerable, but there
is no known spring in this part of Egypt of which the water is so
salt as to be disagreable to the taste.[114] It is their constancy
combined with the purity of their water that makes the springs the
most highly prized of desert water sources.
Springs are mostly on or near the main camel roads, for the roads
are naturally selected so as to utilise these constant water
supplies. Frequently, however, the spring is situated up a lateral
valley some little distance from the main track, and is more or less
difficult of access. The springs of Abu Saafa are on a main road,
where the Wadi Hodein cuts cleanly through the sandstone plateau;
but those of Meneiga, being at the head of a _cul-de-sac_, are
only approachable by a branch track. At large springs the Arabs
generally dig out a series of basins into which the water flows,
so that these are always full of water ready for the camels of a
caravan to drink. At _megals_ there is usually no pool, or only a
very small one, in sand or detritus; this sand is scooped out and
the water is baled from the hole with a tin can. The absence of a
pool is probably due to a desire to check evaporation. The flow at a
_megal_ is frequently so small that only a few litres per hour can
be obtained; the small trickling spring of Sikait, for instance,
was yielding only twenty gallons of water _per diem_ in 1906, but
even this small supply was highly prized by the miners working there,
on account of its purity as a drinking water.
_Megals_ are more likely to run dry than the larger springs, owing
to their smaller collecting area. Any attempt to increase the flow
of springs by blasting or excavation would probably only give an
increase in yield at the expense of constancy; the throttling of the
efflux is doubtless in many cases the chief reason for the perennial
character of the yield of a spring, the rainfall being insufficient
to maintain greater supplies than the springs yield at present.
=Wells.=
The wells of South-Eastern Egypt are mostly shallow excavations
in the alluvia of the wadi floors, tapping the drainage waters
which slowly percolate underground Nilewards and seawards from the
mountain ranges. They are naturally more frequent in the districts
near to the mountain ranges than in the lower reaches of the wadis,
and the best wells are usually in well-defined trunk wadis which
collect the drainage from myriads of smaller valleys. The wells sunk
in the wadis at points remote from the mountain ranges are of immense
importance to travellers crossing from the Nile, forming as they do
the only supplies in an otherwise waterless journey of several days.
On an average, water is reached at a depth of eight to ten metres;
occasionally, where the wadi is crossed underground by a rocky
bar, the natural damming enables water to be reached at very
shallow depths. The shafts dug by the Arabs are generally wide
and very crooked, in order to permit of a man descending to fill a
water-skin. Usually a “well” consists of three or four such shafts
sunk in proximity. Occasionally, especially in the Bisharin country,
the shafts are lined with rubble masonry, and rough timbers may be
stretched across the mouth to facilitate hoisting by ropes. There is
never any hoisting gear except at mines; rope is too much prized by
the Arabs for it to be possible to leave ropes unguarded at a well,
so each caravan uses its own rope and skins. Occasionally, the shaft
is so cranked that the water cannot be seen from above. The reason
for this is chiefly laziness in excavation; it is easier to deepen
a well by driving out laterally a short distance and then sinking a
narrow pit, throwing out the excavated material into the larger main
shaft, than to hoist all to the surface. Near the wells one usually
finds _hods_, or mud basins, into which the Arabs pour the hoisted
water for their animals to drink. Frequently there are high _hods_
for camels and low ones for sheep and goats.
After every considerable rainfall the wells become filled up with
stony downwash, and have to be dug out afresh. There is no protective
wall to prevent infilling; and, contrary to what might at first be
thought, it is not laziness which conditions this circumstance. To
the Arab, wells are a last resource. After rain, all the _galts_
(rock basins) are full of good water. The Arab knows that the supplies
in these _galts_ will evaporate, while those in the wells, covered
in by alluvium, are safe from loss by this cause. He therefore
draws his supplies from _galts_ as long as he can, and only when
these are empty does he open the wells. The main wells never fail
except after unusually prolonged drought, and then the condition
of the Arab is sore indeed. The Bisharin do not drink much water,
preferring to nourish themselves on the milk of their flocks and
herds; but in times of drought the milk supply falls off because
there is not sufficient moist vegetation for the animals to feed on.
The quality of water from the wells varies enormously with their
situation and at different times. When water is abundant, it is
generally good; but as the supply falls off and the wells have to be
deepened, the slow infiltration carries abundance of sodium, calcium,
and magnesium salts from the rocks, and the water is then often very
unpleasant. The following analyses by Mr. Lucas of water-samples
from some of the wells in 1906 will give a good general idea of
the salts present; the figures give milligrammes per litre (parts
per million):—
----------------+------+------+--------+--------+-------------+-------
| | | | | Bir |
|Sikait| Bir | Bir | Bir Abu| Shadli[115] | Bir
| Well.|Masur.|Metawit.|Hamamid.+-------+-----|Helie.
| | | | | I. | II. |
+------+------+--------+--------+-------+-----+-------
Total solid | | | | | | |
matter in | | | | | | |
solution | 7,360| 880| 4,020| 1,720| 2,380 |2,980| 4,040
----------------+------+------+--------+--------+-------------+-------
Cl | 1,263| 57| 1,027| 225| 555 | 749| 323
| | | | | | |
SO3 | 2,530| 263| 1,042| 318| 540 | 776| 1,447
| | | | | | |
CaO | [116]| 200| 350| 330| 310 |[116]| 610
| | | | | | |
MgO | [116]| 29| 116| 87| 69 |[116]| 211
+------+------+--------+--------+-------------+-------
Equivalent of | | | | | | |
Cl as NaCl | 2,075| 94| 1,687| 370| 912 |1,231| 530
| | | | | | |
Equivalent of | | | | | | |
SO3 as Na2SO4 | 1,850| 1,377| 466| 550| 960 |1,377| 2,569
| | | | | | |
Alkalinity to | | | | | | |
methyl orange | | | | | | |
calculated as | | | | | | |
NaHCO3 | 500| 222| 550| 848| 298 | 260| 651
----------------+------+------+--------+--------+-------+-----+-------
All the above waters were quite drinkable, though that of the Sikait
well was rather disagreably salty.
An analysis of the water of one of the Halaib wells in 1895 is given
by Dr. Natterer,[117] who found (in parts per million):—
Cl 336
SO4 449
CO3 48
Dr. Natterer records that the sample, which was clear, tasted slightly
alkaline, and contained very distinct traces of nitrites and nitrates,
free carbon dioxide, free ammonia, and organic matter. During my stay
of four days at Halaib in May 1908, I drank regularly of the local
well-water; I found it very hard, and though the Arabs seemed to
like it, its action on myself was so strongly aperient that I sent
into the mountains to Bir Frukit for purer supplies for use on the
long march to Port Sudan.
As a rule, it is the magnesium salts which are the most harmful
constituents, the sulphate giving a strong purgative character to the
water. Such salts are naturally present in greatest quantity where
the rocks are gypseous, as for instance along the coast to the south
of Halaib, where the wells of Ti Kureitra, sunk in gypsum and lined
with blocks of selenite, yield water of so purgative a character
that all my Arabs who drank of it became violently ill. In districts
where the rocks are of very basic igneous types, such as gabbros and
serpentines, the salt-content may also be fairly high. Water from
diorite country is somewhat better, that from granite better still,
and that from sandstone best of all. There are practically no wells
in clayey strata within the region here treated of, but Bir Qoleib,
which is on the road from Daraw at about two days’ journey east
of the Nile, is sunk at the foot of a clayey scarp, and the water,
when I partook of it in 1907, was clouded with clayey matter so finely
divided as to be unfilterable through a Berkefeld filter even under
strong pressure, while the physiological action of the water was
to produce very marked constipation. Wells near the sea coast are
liable to be very salty from infiltration of sea water. As a rule,
the very salt wells, such as Bir Murra, Bir Muelih, Bir Shalatein,
and Ti Kureitra, are used only by camels and sheep. When the Arabs
have to drink purgative water for lack of other supplies, they often
mix milk with it, and I have found it wise to imitate them in this
respect, with liberal addition of brandy in some cases.
Wells are generally named after the wadi in which they occur, _e.g._,
Bir Abu Hashim is the well in Wadi Abu Hashim. A bitter well is
often called Bir Murra.[118] A deep well is called _Sararat_ by the
Bisharin, _e.g._, Bir Sararat Seyet is the deep well in Wadi Seyet.
Questions are often asked as to whether it is not possible to increase
the available water supplies by sinking fresh wells. Where it is
a question of sinking a new well in the middle of a long waterless
stretch, or where the object is to sink a fresh well near an existing
salty one in order to obtain a drinkable quality of water (and these
are the two most usual cases), success cannot be predicted with any
certainty, even in the most likely looking spots. We must remember
that though the present Arabs may be lazy, the older tenants of the
desert were more active. We have only to look at the old mining
centres to see this. The probability is that the old miners were
just as much worried by the scarcity of water as we are to-day, and
with the cheap convict labour then available we may rest assured
that every attempt was made to increase the supply. And it is not
probable that the Arabs will have allowed to fall into disuse any
existing well on an otherwise waterless road, so that it is likely
that most of the wells in the wadis remote from the mountains are at
spots specially favourable which have been discovered by a laborious
process of trial and error. Confirmation of this view is supplied by
the failure of new wells sunk at considerable cost in likely-looking
places, as for instance at Abu Rahal, where a well carried down to
over sixty metres’ depth failed to find water. Where modern wells
have obtained water, they have usually been sunk near to or on the
site of existing wells, as for instance near the temple of Seti I
and at the different mining centres; in these cases it has sometimes
been found possible to increase the supply by going deeper. And
with regard to obtaining sweet water by sinking new wells near to
old salty ones, no success can be hoped for if the saltiness is
due to a general salt-content in the surrounding rocks; the Mines
Department well in Wadi Mellaha[119] yielded no better water than
the Arab well in the same wadi, because the alluvium everywhere
in the wadi contains abundance of salt. In some cases, it may be,
the promotion of a more rapid flow would lead to a slight lessening
in the salinity; but if a well becomes salt merely by evaporation
resulting from stagnation, that very fact shows that it is not much
used by the ordinary traveller; and moreover the rate of flow of
the underground water is not as a rule sufficiently rapid to yield
large supplies, even from wide excavations.
In the south parts of the country, where the rainfall is greater,
it is possible, nay, even likely, that many new wells could be sunk
with success; but in these localities existing wells are more abundant
and the necessity for new wells does not arise.
=Rock Basins (Galts).=
The typical rock basin, called a _galt_[120] by the Arabs, is a
smooth-sided cavity in the rocky floor of a steep gorge draining
a large mass of high hills. Galts are generally difficult of
access, being situated in the higher parts of very stony wadis,
so that one has to tramp often over miles of steeply rising stony
ground to reach them. Galts abound in all high mountain-masses in
South-Eastern Egypt, and furnish the greater portion of the water
supply of the population. The capacity of galts varies very much;
some hold millions of litres. Often there is a chain of successive
galts at intervals along the length of a gorge, and after rain the
whole series is filled, while much overflows and runs to waste. The
origin of the rocky basins is generally due to pot-holing action on a
large scale. Galts may occur in rocks of any hard type, but are most
commonly met with in eruptive rocks. Sandstone galts never remain
long full, owing to the permeable nature of the rocks. The large
Galt el Aguz near Gebel Um Harba, which from the inscriptions near
it was evidently known and used in Ptolemaic times, is in sandstone,
receiving in fact the superficial run-off from the same high mass
of sandstone hills as furnish the collecting area for feeding by
percolation and underground flow the adjacent springs of Bir Abraq
and Abu Saafa; but the galt is seldom full for more than a month or
two, while the springs are constant.
The water supply of galts depends firstly on the rainfall of the
district; secondly, on the existing drainage system; thirdly, on
the presence and size of eroded basins along the lines of drainage;
fourthly, on the nature of the rocks forming the basin, and, lastly,
on the degree of exposure to evaporation. The rainfall in the Eastern
Desert is often very local. A series of galts full one year may
be dry the next, while those of another area may show a reverse
state of things. The drainage system most favourable to galts is
one formed by the union of long narrow steep-sided gullies into a
single gorge. The presence of basins is conditioned by the steepness
of the drainage and the hardness of the rocky floor; if the rocks
are soft or much crushed, galts are very unlikely to occur. Again,
if the basin is formed of permeable though hard rock, there will be
rapid loss by infiltration. Evaporation is generally far less rapid
at galts than in open country, because being in narrow gorges galts
only receive the sun’s rays for a few hours of the day, and are,
moreover, sheltered from winds.
The quality of galt water varies very much with the interval since
rainfall and with the nature of the rocks. Sandstone galts are very
pure, because of their short life and the siliceous nature of the
rock. Serpentine and diorite galts contain magnesium and other salts,
and as the loss by evaporation continues the water may become somewhat
bitter and purgative by concentration of these saline constituents,
though galts never suffer to the extent that some wells do in this
respect.
A galt is frequently accompanied by a small spring (_megal_ or
_megwel_); the galt represents the run-off, while the spring receives
the percolating water. Thus for months after a galt is empty it
may in some cases be possible to obtain water in small quantity by
scooping out sand-filled rock cavities close to the basin.
Galts are generally named after the mountain in which they occur,
though when large and well known they may have special names given
to them, as in the case of the Galt el Aguz mentioned above.
=Remarks on Water Transport.=
As will be gathered from the map on Plate III, water supplies are
seldom more than two days’ march apart in this part of Egypt. For
the ordinary traveller it will therefore be usually an ample provision
to carry four days’ supply; in special cases, where it is desired
to camp for any purpose remote from water sources, special provision
will of course have to be made. There is seldom any trouble with the
Arabs about their own water, as when their supplies run short one
or two camels can always be detached from a caravan to fill their
skins from the nearest well, and they are always content to travel
day and night for this purpose. With regard to the quantity of water
to be carried, I found ten gallons per European per day to be ample,
including water for cooking and for one’s personal servants. Water
is best carried in rectangular galvanized iron tanks, each holding
ten gallons, fitted with a good brass or wooden plug; two of these
carried horizontally make a light camel load, and on the march one
can add a little in the shape of tents or bedding to the load. I
have tried the barrel-shaped galvanised steel tanks used by the
mining companies, which hold sixteen gallons each and are easily
carried vertically, a pair forming a camel load; but I have found
them much more liable to damage than the smaller rectangular tanks,
and do not recommend them for regular desert travel.
=List of Water Sources.=
In the following list I have summarized all the water sources known
to me in order of latitude from north to south. I believe the list
contains all sources that are of importance, but it is doubtless far
from being complete as regards the rock basins of the mountain areas
for two reasons. Firstly, the Arabs are often reluctant to point out
the sources, more especially in the more arid parts of the Ababda
country; and secondly, as already remarked, since the rock basins
depend for their supplies entirely on comparatively recent rainfall
around them, they vary very much in yield in different years, so
that basins which are of great use in one year may be totally dry
the next, and _vice-versa_, and guides seldom take the trouble to
point out a dry basin, even if in some other year it may have held
a useful store of water.
With regard to the accuracy of the positions given in the list, it may
be remarked that in the case of wells actually visited the position
is given to seconds, and the localisation may be relied on within
at most a few hundred metres; while for wells not actually seen but
whose positions were pointed out by guides from some distance, the
coordinates are usually only given to minutes, and these positions
are uncertain by larger amounts, up to two or three kilometres in
extreme cases.
It must not be assumed that water supplies can _always_ be obtained
at all the localities named. As already remarked, rock basins will
usually only be full if rain has fallen in the district comparatively
recently, large rock basins may furnish supplies for a year after
rainfall, but the smaller ones last only a few months, weeks, or
even days. The reserves are the wells, most of which never run dry
except after a succession of rainless years. But when rock basins
are full, many of the wells are filled with downwash, and digging
must be resorted to in order to re-open them. A traveller arriving
at a “well” sometimes finds no evidence whatever of its existence
beyond the guides pointing to a spot on the ground with the statement
“_el bir hena_” (the well is here). The explanation is that the
well has been filled with alluvial matter washed down the valley by
recent rain; but that same rainfall will have filled the rock basins
in the hills, and the Arabs leave the digging out of the well until
the basins are empty again. In other cases a well may be found to
be dry through the water-level having sunk below the depth to which
the well was last opened, and by deepening it a foot or so one may
obtain a supply.
The notes in the column headed “Remarks,” on the quality of the
water of the various sources, are mostly based on the observations
of a single year, and must therefore only be taken as general
guides. Usually, the shorter the interval since rain has fallen,
the better are the supplies, both in quantity and quality.
LIST OF WATER SOURCES.[121]
-----------------------+--------+---------+--------------------------
Name. |Latitude|Longitude| Remarks.
| N. | E. |
-----------------------+--------+---------+--------------------------
| ° ′ ″| ° ′ ″ |
| | |
Galt Um Tundeba |24 55 25|34 45 53 |Rock basin in ravine, 1
| | |kilometre from Wadi Um
| | |Tundeba. Gave good supply
| | |of pure water in 1906.
| | |
Galt in Gebel Ghuel |24 54 0|34 39 0 |Large rock basins,
| | |yielding a good supply in
| | |1905-1906.
| | |
Bir Muelih |24 51 35|33 59 52 |In Wadi Muelih. Very
| | |salt, only drinkable by
| | |animals.
| | |
Hangalia well |24 50 27|34 35 40 |Modern well in Wadi
| | |Hangalia, sunk by miners.
| | |Supply small and of poor
| | |quality.
| | |
Galt Um Karaba (Migif)|24 48 48|34 27 55 |Large rock basins,
| | |yielding a good supply
| | |in 1905-1906. Rather
| | |difficult of access for
| | |camels.
| | |
Bir Ghadir |24 48 25|34 47 0 |Well in Wadi Ghadir.
| | |Filled by downwash in
| | |1906.
| | |
Megal el Harami |24 47 34|34 34 15 |Small spring in ravine on
| | |west side of Wadi Nugrus.
| | |Yields for some months
| | |after rainfall. Water
| | |very good.
| | |
Bir Sibrit |24 43 0|33 58 0 |Well in Wadi Sibrit;
| | |water about 8 metres
| | |down, of good quality.
| | |Supply stated to be
| | |constant.
| | |
Bir Murra |24 41 0|34 11 0 |Well in Wadi Shait. Water
| | |salt, only drinkable by
| | |camels.
| | |
Hamish mine |24 41 0|34 6 0 |Water in mine shafts,
| | |that in the westernmost
| | |of three shafts good
| | |in 1906. Well in Wadi
| | |Hamish, close to mines,
| | |15 metres deep, dry in
| | |1906.
| | |
Sikait, spring |24 40 50|34 47 10 |Tiny trickling spring of
| | |good water. Yields only
| | |about 50 litres per day,
| | |but supply of very good
| | |quality and said to be
| | |constant.
| | |
Sikait, north well |24 40 12|34 46 0 |Modern well, sunk by
| | |miners. Was yielding fair
| | |quantity in 1906, but of
| | |mediocre quality.
| | |
Sikait, south well |24 39 38|34 47 45 |Similar to last; both
| | |wells are in the floor of
| | |Wadi Sikait.
| | |
Bir Um Gubur |24 37 0|34 5 0 |Well in Wadi Shait. Water
| | |about 8 metres down, good
| | |and plentiful in 1906.
| | |
Bir Abu Had |24 34 0|34 36 0 |Well in Wadi Abu Had,
| | |near its head, at
| | |junction of two roads to
| | |Sikait. Water salty.
| | |
Bir Masur |24 31 0|34 13 0 |Several wells in floor of
| | |small wadi. Water good,
| | |about 10 metres down in
| | |1906, but supplies cannot
| | |be relied on.
| | |
Bir el Ranga |24 26 0|35 13 0 |Very salt well, close to
| | |sea.
| | |
Galt Um Gerifat |24 22 55|34 40 20 |Rock basin in gorge off
| | |Wadi Huluz. Was yielding
| | |good supply in 1906.
| | |
Bir Metawit |24 17 0|34 31 0 |Well in Wadi Metawit, on
| | |road between Bir Shadli
| | |and Bir Masur. Said to
| | |yield constant supply.
| | |Water about 8 metres
| | |down, good and clear in
| | |1906.
| | |
Bir Khashab |24 16 0|34 23 0 |Well in Wadi Khashab. Not
| | |to be depended on. Dry
| | |in spring of 1906, but
| | |yielding a small supply
| | |of mediocre character in
| | |the autumn of the same
| | |year.
| | |
Bir Shadli |24 12 3|34 37 55 |Spring or well near tomb
| | |of Sheikh. Perennial
| | |supply of variable
| | |quality and quantity.
| | |Favourite meeting place
| | |of Ababda Arabs.
| | |
Bir Abu Hamamid |24 12 0|34 29 0 |Well sunk about 7 metres
| | |in floor of Wadi Abu
| | |Hamamid. Yielding large
| | |supplies of rather salty
| | |and muddy water in 1906.
| | |
Amar Spring |24 10 0|35 9 0 |Spring of good water in
| | |diorite hills south-east
| | |of Gebel Hamata.
| | |
Well in Wadi Abu |24 7 0|34 26 0 |Wells sunk in wadi floor.
Hamamid | | |Dry in 1906.
| | |
Bir Helie |24 5 0|34 32 0 |Well in Wadi Helie.
| | |Excellent water in spring
| | |of 1906, but rather
| | |salty later on in the
| | |year. Quality evidently
| | |varies considerably with
| | |interval since rainfall.
| | |
Megal Um Gunud |23 58 50|35 10 50 |A smaller rock basin in
| | |Gebel Um Gunud, off Wadi
| | |Lahami, near to Galt Um
| | |Gunud.
| | |
Galt Um Gunud |23 58 10|35 11 20 |Rock basin, in Gebel Um
| | |Gunud. Yielded supplies
| | |in 1906. Accessible from
| | |Wadi Lahami.
| | |
Megal el Selaia |23 56 55|34 52 50 |Small spring in sand at
| | |foot of rocks near Gebel
| | |Selaia. Yield small and
| | |not to be depended on for
| | |long after rain.
| | |
Galt Batoga |23 51 20|35 21 30 |Rock basin at foot of
| | |Gebel Batoga off Wadi
| | |Kalalat. Water good,
| | |plentiful, and fairly
| | |easy of access in 1907.
| | |
Galt Um Maiyat |23 50 2|35 18 15 | —
| | |
Galt in Gebel Dahanib |23 44 45|35 9 50 |Rock basin in ravine,
| | |containing water after
| | |rain; about a cubic metre
| | |in 1907.
| | |
Bir Shenshef |23 44 0|35 23 0 |Several small wells in
| | |Wadi Shenshef near ruins.
| | |Water good.
| | |
Bir Abu Hashim |23 41 56|34 4 26 |Several wells in alluvial
| | |floor of wadi. Water good
| | |and plentiful, about 8
| | |metres down in 1907.
| | |
Bir Betan, west well |23 38 0|35 3 15 |Well in floor of Wadi
| | |Betan, about 600
| | |metres lower down than
| | |foregoing, close to where
| | |Wadi Um Eleiga enters
| | |Wadi Betan. Filled by
| | |downwash in 1907.
| | |
Bir Betan, east well |23 37 55|35 3 35 |Well in floor of Wadi
| | |Betan, near small seyal
| | |tree. Filled by alluvium
| | |in 1900.
| | |
Galt near Gebel Abu |23 37 0|35 5 20 |Rock basin in north-west
Dahr | | |flank of Gebel Abu Dahr.
| | |Was yielding a good
| | |supply in 1907.
| | |
Bir Rahaba |23 33 30|35 9 54 |Well in alluvium of
| | |Wadi Rahaba. Filled by
| | |downwash in 1907.
| | |
Bir Abu Reye |23 33 0|35 9 0 | —
| | |
Galt el Aguz |23 32 30|34 35 0 |Large rock basin in
| | |sandstone, near easy pass
| | |over watershed at head
| | |of Wadi Arned. Yields
| | |excellent water for short
| | |time only after rain.
| | |
Bir el Gahlia |23 31 0|35 8 0 | —
| | |
Bir Abu Beid |23 31 0|34 58 0 |Well in Wadi Abu Beid.
| | |Was yielding a fair
| | |quantity of good water in
| | |1906.
| | |
Bir el Sunta |23 25 50|34 47 40 |Spring forming pool at
| | |foot of sandstone scarp
| | |of Gebel Abraq. Good
| | |water.
| | |
Bir Abu Dibesat |23 25 6|34 47 10 |Spring forming small pool
| | |at foot of sandstone
| | |scarp of Gebel Abraq.
| | |Water good.
| | |
Bir Abraq |23 24 56|34 47 20 |Spring forming pool in
| | |gully of Gebel Abraq.
| | |Supply constant, good,
| | |and plentiful.
| | |
Bir Gumbit |23 24 0|34 49 0 |At edge of sandstone
| | |hills; probably a spring
| | |similar to those of Abraq.
| | |
Bir Orga |23 21 0|35 3 0 |Well stated to exist in
| | |Wadi Orga el Rayani.
| | |
Megal near Abu Saafa |23 19 30|34 48 40 |Spring? in small wadi off
| | |Wadi Hodein. Unimportant,
| | |being close to Abu Saafa
| | |Springs.
| | |
Abu Saafa Springs |23 18 9|34 47 45 |Four springs yielding
| | |constant supply of very
| | |pure water, at foot of
| | |sandstone scarp in Wadi
| | |Hodein. Pools easy of
| | |access to camels.
| | |
Galt in Wadi Gihab |23 17 5|34 48 10 |Large rock basin in Wadi
| | |Gihab Yakub Abu Derb.
| | |Pool of good rain water 6
| | |metres diameter in 1907.
| | |Easily accessible to
| | |camels.
| | |
Bir Um Reit |23 13 36|34 35 3 |Well sunk in floor of
| | |Wadi Um Reit. Water of
| | |mediocre quality.
| | |
Bir Dif |23 12 42|34 49 55 |Spring forming two pools
| | |in the stony bed of Wadi
| | |Dif. Water good.
| | |
Bir Shalatein |23 8 5|35 36 28 |Very salt well near sea
| | |at mouth of Wadi Hodein.
| | |Drinkable only by camels.
| | |Point on administrative
| | |boundary between Egypt
| | |and the Sudan.
| | |
Bir Beida, north well |22 58 6|35 18 10 |In Wadi Beida, about 500
| | |metres further down than
| | |south well, at a bend in
| | |the wadi. Good water,
| | |yields three years after
| | |rainfall, but supply
| | |infiltrates slowly.
| | |
Bir Beida, south well |22 57 53|35 18 10 |In Wadi Beida, close
| | |to where track to Bir
| | |Meneiga leaves it. Dry in
| | |1907.
| | |
Bir Madi |22 47 46|35 1 48 |Well sunk in alluvium of
| | |Wadi Madi, at a bend in
| | |a narrow gorge at foot
| | |of a high granite hill.
| | |Plenty of good water in
| | |1907-1908.
| | |
Bir Meneiga, north |22 47 8|35 12 20 |Similar to Bir Meneiga,
spring | | |south spring, to which it
| | |is very close. Point on
| | |administrative boundary
| | |between Egypt and the
| | |Sudan.
| | |
Bir Meneiga, south |22 46 55|35 12 15 |Tiny pool in rocky
spring | | |floor of Wadi Meneiga,
| | |which refills as fast
| | |as emptied. Easily
| | |accessible to camels.
| | |Water excellent.
| | |
Bir Korbiai |22 46 55|35 10 35 |Two wells of excellent
| | |water in the rocky gorge
| | |of Wadi Korbiai. Said to
| | |yield for three or four
| | |years after rain.
| | |
Bir Muqur |22 42 26|35 18 5 |Trickling spring with
| | |pools in serpentine, in
| | |Wadi Muqur. Was yielding
| | |about five litres per
| | |minute in 1908.
| | |
Bir Sararat Seyet |22 41 10|35 1 59 |Deep well in Wadi Seyet;
| | |filled by downwash in
| | |1907-1908.
| | |
Bir Diqdib |22 41 0|35 13 0 |Spring? high up in Wadi
| | |Diqdib, south part of
| | |Gebel Gerf.
| | |
Bir Adal Deib |22 40 30|36 4 30 |Salt well, close to sea.
| | |
Ti Dabei Hamra Dom |22 39 55|35 38 40 |Shallow excavations in
| | |alluvium and sand in the
| | |hills of Hamra Dom, only
| | |yielding supplies for a
| | |short time after rainfall.
| | |
Bir Baaneit |22 39 30|35 18 40 |Spring? situated a short
| | |distance up Wadi Baaneit.
| | |Said to yield constant
| | |but limited supplies.
| | |
Bir Bint el Dreb |22 34 0|35 9 0 | —
| | |
Bir Um Rasein |22 29 10|35 20 20 |Near Gebel Um Rasein.
| | |
Bir Nabit |22 26 50|36 21 50 |Close to sea. Probably
| | |salty.
| | |
Bir Um Bishtit |22 26 33|35 33 45 |In narrow winding gorge
| | |off Wadi Um Bishtit.
| | |Said to yield good water
| | |supplies for a year
| | |after rainfall and small
| | |supplies longer. Full of
| | |downwash in 1908.
| | |
Galt Osnei |22 25 35|35 50 40 |Rock basin in small
| | |granite hill; full only
| | |after rain.
| | |
Meis-heit-ar, north |22 22 4|35 35 12 |Galt in rocky gorge off
galt | | |Wadi Meisah. Yielding
| | |good supply in 1908;
| | |preferred to Bir Meisah
| | |for quality.
| | |
Bir Abu Hodeid |22 22 0|35 17 0 |Large and important
| | |spring in Wadi Abu Hodeid.
| | |
Bir Odis Maaleq |22 22 0|35 16 0 |Large and important
| | |spring in Wadi Odis,
| | |reached by a mountain
| | |track from Wadi Delawet.
| | |
Bir Meisah |22 21 8|35 35 50 |Well-known well in
| | |Wadi Meisah. Filled by
| | |downwash in 1908. Water
| | |said to be of only
| | |moderate quality.
| | |
Bir Qidmib |22 21 0|35 29 0 | —
| | |
Bir Abu Ramad |22 20 40|36 26 50 |Close to sea. Probably
| | |salty.
| | |
Bir Shinai |22 20 0|35 15 0 | —
| | |
Meis-heit-ar, south |22 21 15|35 35 20 |Galt in rocky gorge off
galt | | |Wadi Meisah. Yielding
| | |good water in 1908.
| | |
Megwel Adar Aqdeib |22 17 50|35 38 40 | —
| | |
Megwel Um Edwa |22 16 50|35 32 45 |Chain of rock basins and
| | |small spring in stony
| | |gorge on east side of
| | |Hadal Aweib Meisah.
| | |Rather difficult for
| | |camels. Water good.
| | |
Megwel Didaut |22 16 25|35 37 10 | —
| | |
Megwel Akau |22 14 50|36 21 10 |Small spring? on north
| | |side of Gebel Elba.
| | |
Bir Kansisrob |22 14 35|36 22 0 |Large well; water good
| | |and plentiful. Bisharin
| | |camping ground.
| | |
Megwel Hamida |22 14 25|35 47 0 |A tiny trickling spring
| | |of saline water in a
| | |narrow gorge. Rock basin
| | |above it, dry in 1908.
| | |
Halaib wells |22 13 25|36 38 40 |Several wells in village.
| | |Water plentiful, strongly
| | |purgative to Europeans,
| | |though it has no effect
| | |on the natives of the
| | |place.
| | |
Bir Akwamtra |22 13 1|36 17 58 |An excellent well at
| | |the foot of Gebel Elba;
| | |important Bisharin
| | |camping ground.
| | |
Bir Hilwit Hasium |22 13 0|35 14 0 | —
| | |
Bir Nubitra |22 12 50|35 46 20 |Said to yield only small
| | |supply.
| | |
Megwel Um Ein |22 12 30|35 39 40 | —
| | |
Bir Meheriqa |22 12 10|35 56 35 |Spring on east side of
| | |Wadi Di-ib. Water rather
| | |salty, but drinkable and
| | |clear.
| | |
Bir Kagog |22 11 0|35 16 0 |Small well in Wadi
| | |Hasium, near its head.
| | |
Galt in Wadi Kirir |22 10 0|35 19 0 | —
| | |
Bir Sararat Serimtai |22 8 50|36 24 15 | —
| | |
Bir Mashushenai |22 8 30|35 49 30 | —
| | |
Megwel Aqwem |22 8 0|35 41 0 | —
| | |
Bir Guqub |22 8 0|34 27 0 |Galt and spring? Water
| | |good but variable in
| | |quantity. Was yielding in
| | |1906.
| | |
Bir Salalat O Sir |22 7 23|36 19 0 | —
| | |
Ti Kureitra |22 5 50|36 46 40 |Four wells sunk in
| | |gypseous strata near sea;
| | |water strongly purgative.
| | |
Bir Egat |22 5 0|34 54 0 | —
| | |
Bir Frukit |22 2 0|36 36 0 |Well in Wadi Aqilhoq;
| | |water good and plentiful.
| | |
Bir Himeitra |22 0 0|35 15 0 | —
| | |
Bir Qabatit |21 57 55|36 51 17 |Well in Wadi Qabatit,
| | |1½ kilometres from sea;
| | |water salty, but said not
| | |to be purgative.
-----------------------+--------+---------+--------------------------
[Footnote 113: Part of this chapter is taken from my paper on
“Desert Water Supplies” in the _Cairo Scientific Journal_ for 1908
(Vol. II), pp. 234-242.]
[Footnote 114: I except the tiny spring called Megwel Hamida, which
is a mere trickle of very salty water.]
[Footnote 115: Samples collected on two different dates; the figures
show the variability of the water at the same well.]
[Footnote 116: Not determined.]
[Footnote 117: _Berichte der Commission für Oceanographische
Forschungen_, Sechste Reihe, Wien 1898, p. 510.]
[Footnote 118: Cf. the _Marah_ of the Israelites, Exodus 15,
23. “They could not drink of the waters of Marah, for they were
bitter; therefore, the name of it was called Marah.”]
[Footnote 119: This is in latitude 27° 35′ N., and therefore
outside the limits of the region specially described in this memoir,
but is quoted as a useful example.]
[Footnote 120: Pronounced to rhyme with the English word _shalt_.]
[Footnote 121: The map of the roads and water sources on Plate III,
p. 26, should be referred to in connexion with this list.]
PLATE XX.
[Illustration: GEOLOGICAL MAP OF SOUTH-EASTERN EGYPT.
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
CHAPTER VIII.
* * * * *
=GEOLOGY.—SEDIMENTARY ROCKS.=
* * * * *
Only a small proportion of South-Eastern Egypt is covered by
sedimentary rocks. As will be seen from a glance at the geological
map on Plate XX, sedimentary strata are to be found only in the
north-western and central portions of the area, where the Nubian
sandstone which covers so much of the country close east of the
Nile terminates in a long south-easterly projection, and along
certain portions of the coast, where small outliers of Nubian
sandstone and patches and strips of gypseous limestones and coral
reef occur. The oldest rocks of undoubted sedimentary origin, the
Nubian sandstones, are of Cretaceous age. Tertiary beds are absent,
except for the gypseous strata of Ras Benas, which may possibly be
Miocene. Quaternary deposits are represented by Pleistocene and
Recent coral reefs and beach deposits, and by accumulations of
alluvial downwash, blown sand, and calcareous tufa.
The sedimentary deposits may thus be classified into:—
(1) _Recent Deposits_ (coral reefs and raised beaches, blown sand,
alluvial deposits, and calcareous tufa).
(2) _Gypsum and Gypseous Limestones_ (of uncertain age, possibly
Miocene).
(3) _Nubian Sandstone_ (Cretaceous).
=Coral Reefs and Raised Beaches.=
Coral reefs fringe almost the entire coast-line of South-Eastern
Egypt, rendering the coast one of the foulest in the world for
shipping. Coral forms the islands of Wadi Gemal, Gulhan, Mukawar,
Mirear, Seyal, and Halaib, these rising to a few metres above the
sea; but in general it is not met with on the main land except close
to the shore. The reefs may extend, slightly raised, some distance
inland, but cannot be seen owing to the sand and downwash from the
mountains which covers the sloping coast-plain. At low water great
expanses of nearly level coral reef, stretching out for a kilometre
or more from the shore, are exposed in places, especially near Ras
Benas. Frequently a line of reefs can be seen running for many miles
parallel to the coast at a distance of a kilometre or more from it;
these outer reefs can be traced in windy weather by the breaking
of waves on them, and in calm weather by the lighter colour of the
water over them. There is frequently deep water between the outer
reefs and the shore. Openings in the outer reefs, through which boats
can pass into the sheltered water within, are called _mersas_ by the
Arab boatmen; they frequently occur opposite the mouths of the larger
wadis. Coral reef forms a tough, hard, and very porous limestone, with
an extremely rough surface on which the structure of the astraean and
other corals composing it can be clearly seen. It has been used for
building the jetty at Halaib, and rough blocks of it were anciently
employed for building at Berenice, as well as in the tombs at Suakin
el Qadim; but its porosity and intractability would never recommend
it as a building stone if any other could be found locally.
In close association with coral reefs are beach deposits of
Pleistocene age. These occur round the hills near the tip and on the
north side of the peninsula of Ras Benas, where they cover the slopes
of the gypseous limestone hills. Low hills and banks of very white
aspect occur near the sea further north; these are probably also
raised beaches, though they have not been visited and may possibly
be gypsum. Near the tip of Ras Benas these beach deposits are gritty
limestones with abundant casts of lamellibranchs and gasteropods,
mostly in bad preservation, as well as various echinoids, among
which M. Fourtau has identified the species _Brissus carinatus_
as one of the most abundant.
=Blown Sand.=
The dune-forming sand in South-Eastern Egypt is exactly similar to
that which covers such large areas in the Libyan Desert. It consists
of well-rounded quartz grains, averaging about a millimetre in
diameter; the grains are usually of a golden-yellow colour, owing
to their being coated with a thin superficial film of iron oxide.
The only area where sand dunes are of any considerable magnitude
or extent in South-Eastern Egypt is the tract called I Hubâl
(lit. “the sand dunes”) which extends from Wadi Meisah to
Wadi Aideib, fronting the hills of Ti Keferiai, Geror, Balatitda,
Sul Hamid, and El Sela. The north faces of all these hills and the
smaller hills north of them are swathed in thickly accumulated sand
to such an extent as to make travelling over them difficult. The
reason for the heavy sand accumulation at this particular place is
that the north-west wind, which is the prevalent wind over Egypt
proper, here meets with south-easterly winds coming up the Red Sea,
causing a local calm and a consequent dropping of the sand borne
from the Nubian sandstone areas by the north-west wind. Thus the
same climatic conditions which give rise to the rich vegetation on
the Elba mountains cause at the same time extreme desert conditions
in the tract immediately north-west of them.
Sand accumulations of less magnitude occur in and about the lower
reaches of the Wadi Hodein, in the great valley to the north of
Berenice, on the plain west of Gebel Um Harba, and at some few
other places, but they are seldom so extensive as to cause a serious
hindrance to travel.
Besides transporting the ordinary dune-forming sand, the action of
the wind is responsible for a considerable amount of redistribution
of the coarser granitic and other sand produced by the disintegration
of igneous rocks. In high winds this coarse sand, in angular grains
as large as peas, is blown about on the coast-plain to considerable
distances from the places where it was originally deposited by
water transport.
=Alluvial Deposits.=
The degradation of the mountain and hill masses which is constantly
going on under sub-aerial agencies (disintegration by variations of
temperature, and transport by water during occasional rain storms)
has in the course of centuries resulted in immense accumulations of
alluvial material (sand and gravel) along all the drainage lines and
on the plains. Disintegration is in many places greatly facilitated
by the crushed nature of the rocks, due to the tectonic movements
which they have suffered during the process of folding and mountain
formation. This fact is specially evident in the case of the more
basic rocks. Serpentines, for instance, are frequently so crushed
and cracked that one may search in vain over a whole mountain for a
place where the rock is sufficiently free from cracks to allow of a
hand-specimen of the ordinary size being extracted without breaking
up into fragments under the hammer. In the more acid rocks, like the
granites, crushing has been a less powerful aid to disintegration,
and here the diurnal temperature-range has been the principal factor;
the rock, being an aggregate of crystals of different materials with
different coefficients of expansion, has been easily broken up at its
surface by the constant differential motion of its component grains,
resulting in the formation of coarse granitic sand. Chemical action in
denudation is of quite subordinate importance. Though some chemical
action has taken place, as for instance in the kaolinisation of the
felspars, we find as a rule that the alluvial accumulations consist
principally of unaltered rock fragments.
In material, the alluvial accumulations are of the same varied
nature as the mountains from whose degradation they have originated,
ranging from very basic mineral substances, such as serpentine,
to the most acid, such as quartz. The relative proportions of
the different materials in the alluvial deposits do not, however,
correspond as a rule with the proportions in which they enter into the
mountain masses. Not only are heterogeneous rocks, such as granites
and diorites, far more rapidly disintegrated by temperature-changes
than are the more homogeneous rocks such as felsites and serpentines,
but the fragments produced by the disintegration of granitic rocks are
rounder and of much smaller size than the fragments resulting from
the breaking up of felsites, schists, and serpentines. The result
is that granitic detritus is transported to greater distances and
distributed over larger areas than the detritus of the closer-grained
and more homogeneous rocks. In approaching a mountain composed of
about equal parts of, say, granite and serpentine, we accordingly
find the lower portions of the wadi consist chiefly of granitic sand,
while the coarser and more angular detritus of serpentine is only seen
in abundance in the higher parts of the drainage channel. The nature
of the alluvium of the wadi floor occasionally gives its name to the
wadi; thus, of the two wadis which by their junction form Wadi Khoda,
one is called Wadi Salib el Azrak, because its alluvium consists of
dark rock fragments, while the other is called Wadi Salib el Abiad,
because its floor is formed of white granitic sand. (_Azrak_ = dark;
_Abiad_ = white).
In size, the fragments composing alluvial detritus vary from huge
blocks weighing tons down to the finest sand whose grains are only
a fraction of a millimetre in diameter. As a rule, of course, the
larger fragments are found near the heads of wadis, and the finer
sands in their lower reaches and on the plains. But often we find
great boulders mixed with the sand at immense distances from the
parent mountain mass; the heavier rain storms which occasionally
break over the mountains produce for short periods such immense
rushes of water down the wadis, that great boulders are swept along
and incorporated in the finer material which is deposited in times
of more normal rainfall. Thus it is no uncommon thing in sinking
a well in a wadi fifty kilometres or more from the mountains to
encounter great boulders in the sandy alluvium.
In shape, the alluvial fragments vary very much, according to
their mineral nature and the amount of rolling they have received
in transport. Foliated rocks, like schists and slates, produce
typically flaky fragments which seldom attain any high degree of
rounding; the same is true of serpentines which have been shattered
by crushing. Granitic rocks produce generally more symmetrical
fragments, though granitic sand is typically angular unless it has
been transported for considerable distances. The larger blocks are
generally rounded in the case of granitic rocks, even when they
have not travelled for any great distance; for if a cubical block
of granite be exposed to weathering, disintegration takes place
most rapidly at the corners, and the block eventually becomes
more or less spheroidal without having moved at all. This can be
well seen in such masses as Gebel Selaia, where the granite boss
is thoroughly well rounded _in situ_. The same phenomenon can be
noticed in certain dolerites, where portions of the rock detached
by joint planes have weathered _in situ_ into forms like cannon
balls. The more homogeneous rocks like felsite and serpentine,
as well as the foliated rocks like gneisses, schists, and slates,
do not show much of this rounding _in situ_, as they yield to the
stresses of expansion and contraction by breaking along planes of
crushing or foliation, producing separate masses which preserve most
of their angular shape. In the lower reaches of the wadis and on the
plains, of course, all the materials are more or less rounded, owing
to the attrition to which they have been subjected during transport.
Of the thickness of the alluvial sands and gravels very little is
known. But that it exceeds eight metres in many of the wadis is
proved by wells sunk to that depth. On the coast-plain it may be
vastly thicker, for Grabham[122] mentions that borings made in the
maritime plain near Port Sudan have been carried down to 1,000 feet
(305 metres) in the deposits. Only a very small proportion of the
alluvial detritus brought down the wadis enters either the sea or the
Nile; for the storm-formed streams, though violent in the mountainous
tracts, commonly cease by being absorbed in the thirsty wadi floors
and plains before reaching either the sea or the river. Bearing this
in mind, and the ages through which the actions of denudation and
transport have gone on, we can well imagine how great must be the
total quantity of detritus accumulated.
In some wadis there are high banks of old detritus through which the
streams have cut their way. In the Wadi Meneiga, for instance, there
are terraces of alluvium, some eight or ten metres high, on either
side of the present water channel; these terraces, which are about
two kilometres lower down the wadi than the wells, are covered with
rude rubble ruins, the remains of dwellings erected out of reach of
the occasional streams which rush down the wadi after rain.
At the east foot of Gebel Hamra Dom are some well stratified friable
sand rocks and sandy clays, about ten metres thick, ending abruptly
against the granites and schists of the hill-mass. These beds appear
to be ancient alluvial deposits. They contain ferruginous scales and
show sun-cracks in places, while the materials are finer and more
distinctly stratified than one would expect to be brought down from
the mountain under present conditions.
It is to the alluvial material in the wadis that the Eastern Desert
owes most of its perennial water supplies and the vegetation
it possesses. The alluvial deposits are the great conservers of
water. Pools form, it is true, in the bare rocky beds of the higher
drainage lines, and may last for many months where they are screened
by the walls of a gorge from wind and sun, and are in consequence not
subject to rapid evaporation. But such pools are difficult of access,
and afford but a precarious source of water supply because they are
liable to dry up if a long period passes without rain. The alluvium
of the wadis absorbs the rainfall and protects it from evaporation,
so that even in very dry years water may be found by excavating in it
at suitable places to depths of a few metres. Almost all the wells
which are so important to travellers crossing the desert from the
Nile are of this character. The abundance of trees which flourish
in so many of the wadis likewise derive their nourishment from the
water conserved in the alluvium of the wadi floor.
=Calcareous Tufa.=
Small deposits of calcareous tufa of recent origin have been noted in
the Wadi Um Tundeba and in a gorge on the east side of Gebel Ghuel,
as well as round the little trickling spring called Megwel Hamida
in the south part of the region.
At Um Tundeba the deposit occurs in a little gully close to a well
known _galt_ or pool of rain water. The deposit is not extensive,
and has doubtless been formed by the evaporation of trickling
drainage-water which had absorbed lime from the rocks. The tufa
(10,374) is a pale brown rock of rather porous nature; it envelops
fragments of schist-debris from the surrounding rocks.
The calcareous tufa of Gebel Ghuel is a more impressive deposit,
though its total mass is not very great. It occurs at a point of
sudden fall in a narrow rocky gorge leading to the Wadi Ghadir in
about latitude 22° 53′. Proceeding up the gully one is confronted
with a great curtain-like mass of tufa covering the face of a high
ledge like a solidified cascade. Here also the origin is clearly due
to trickling of lime-laden drainage-waters over the ledge of rock,
which forms a step in the wadi floor.
Fragments of tufa were also seen round about Gebel Allawi, though
the rock was not traced to its source. As only a relatively small
number of rocky gullies have been explored, it is likely that similar
deposits to those above described occur in many other places.
=Gypsum and Gypseous Limestones.=
The occurrences of gypsum and gypseous limestone beds in South-Eastern
Egypt are restricted to the coastal regions. The most prominent of the
deposits are those on Ras Benas (_see_ map on Plate XXI), where the
beds form white hills rising to 188 metres above sea-level. Further
north, gypseous deposits have been found by Dr. Hume to exist near
the sea at Bir el Ranga, and by Mr. Ferrar the same beds have been
recorded as occurring near the coast in the neighbourhood of Wadi
Igli. It appears probable that the gypseous strata form a continuous
or nearly continuous strip extending along the coast down to latitude
24° 22′, as shown on the geological map on Plate XX, but more
complete observations may show that the distribution of the beds is
somewhat different from that indicated. On the coast-plain south
of Ras Benas, gypseous beds are not exposed except in the extreme
south-east corner of Egypt, where they form small patches at Halaib
and round the wells of Ti Kureitra.
At Ras Benas, where the beds have been studied in most detail,
they consist of gypsum and anhydrite [11,513][123] alternating with
sandy marls and marly sands, forming hills much cut-up by steep sided
narrow ravines. The weathered faces of the rocks are very soft, and
the disintegrated material forms a stretch of soft gypseous sand,
into which one’s feet sink four or five centimetres at every step,
between the hills and the shore. At Halaib, gypseous limestones crop
out from under the gravel of the coast-plain and form low banks;
the gypsum is here associated with calcareous grits [12,152, 12,114]
and conglomerates, the latter having boulders of igneous rock set
in a calcareous matrix. Near Ti Kureitra wells, the gypsum exposures
contain much crystalline selenite, blocks of this material being used
in the masonry lining of the wells. Both at Bir el Ranga and on Ras
Benas the gypsum is found to contain small pockets of native sulphur.
No fossils have been found in the gypseous strata, and their
geological age is uncertain. The beds are younger than the Nubian
sandstone, since they overlie that formation at Bir el Ranga. Their
occurrence only near the coast leads one to regard them as having been
formed after the Red Sea occupied its present position; but whether
they originated as direct gypseous deposits, or were produced by
the alteration of pre-existent Cretaceous or Tertiary limestones is
not yet quite certain. It is noteworthy that at Ras Benas, where the
gypseous strata rest on diorite and hornblende granite, the igneous
rocks are considerably altered as if by weathering, with a strong
brick-red colour due to the oxidation of ferruginous matter.
PLATE XXI.
[Illustration: GEOLOGICAL MAP OF RAS BENAS
Ball. Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1910. (60-190)]
=The Nubian Sandstone.=
The Nubian sandstone covers a comparatively small portion of
South-Eastern Egypt, occupying only about one-tenth of the total area
under consideration. The greater portion of it forms the eastern
termination of the vast sandstone plateaux which stretch eastward
from the Nile towards the igneous and metamorphic back-bone of the
Red Sea mountains, but there are in addition some small patches on
the eastern side of the watershed which are interesting as showing
that the deposition of the sandstone was not confined to the western
side of the mountain ranges.
The most northerly exposure of Nubian sandstone in the district
here described extends with some breaks southward from near Gebel
Sufra to near Gebel Homr Akarim, forming low hills. Further south,
it comes in again on both sides of the Wadi Garara, forming the hills
of Felieiti and Abu Hashim. In the sandy plain around the Wadi Timsah
are outlying sandstone hills of considerable height and extent,
the principal being Gebels Nuggur, Mulgata, and Ziraga. Further
south-west, the Nubian sandstone forms an extensive high broken
plateau stretching southward from near Gebel Zergat Naam to near
Gebel Um Reit, sending out a long tongue south-eastwards across Wadi
Dif to near Gebel Nigrub el Tahtani. This tract of broken sandstone
plateaux bears various names in different parts, Gebels Um Harba, Um
Khafur, Dagalai, Shebakhit, Awamtib, Um Sididad, Abraq, Hodein, Dif,
Anfeib, and Kala, all forming parts of the same great sandstone mass,
though separated by wadis from each other. Small outliers of Nubian
sandstone cap the hills of Gebels Reietit, just north of latitude
23°, near the meridian of 34°, and Gebel Seiga, in latitude 22°
44′, longitude 34° 16′.
On the eastern side of the watershed, Nubian sandstone extends
for some distance near the coast opposite the Gulhan islands, and
also forms small thin outliers south of the Wadi Hodein. The most
southerly point where the sandstone has been met with in the area
is a small outlier in latitude 22° 36′, a few kilometres east of
Gebel Hamra Dom.
In petrographical characters the Nubian sandstone is remarkably
uniform, consisting of medium-sized silica grains set in a more
or less ferruginous cement; the colour varies from nearly white,
through various shades of brown, to nearly black, according to the
amount of iron present. It is generally well bedded, and frequently
much jointed. There is usually a marked absence of the clay beds
which are associated with the Nubian sandstone in other parts of
Egypt. The basal beds are generally pebbly, forming conglomerates in
some places. Concretions are found in the rock at some points, notably
to the north of Gebel Um Harba. Some of the concretions are hollow,
the shell being of hard dark ferruginous sandstone while the interior
is filled with a powder of snow-white chalky matter containing sand
grains. The only fossils observed in the sandstone within the area
described were collected by Mr. Charteris Stewart in the plain of
Um Harba; they consist of crocodile scales and various shells. From
these and the fossil shells found further west in sinking a well in
Wadi Abu Rahal,[124] it may be concluded that the Nubian sandstone
here, as in the Nile Valley, is of Cretaceous age.
Intrusions of igneous rock into the sandstone have only been observed
at two points in the area, _viz._, near the western foot of Gebel
Awamtib, where a basic dyke runs through the sandstone, and on the
Red Sea coast, near Bir el Ranga, where Dr. Hume has found andesite
interbedded in the sandstone. A bed of diabase, now much altered,
underlies the sandstone near Wadi Muelih, and is possibly of
contemporaneous origin.
In thickness, the Nubian sandstone attains a maximum of about
350 metres in several places round about Bir Abraq and the Wadi
Hodein. Its thickness must at one time have exceeded this, for the
upper surfaces have suffered much denudation, and are not capped by
younger rocks.
Some interest attaches to the maximum altitude reached by the Nubian
sandstone beds. The highest point at which it has been observed is at
Gebel Seiga, whose sandstone cap is 905 metres above sea-level. The
highest point reached by the rock on the great plateau round about
Wadi Hodein is Gebel Kala, 846 metres above sea.
In contradistinction to the same beds which form the plateau between
longitude 34° and the Nile, the Nubian sandstones within the area
here described show considerable disturbances from their original
horizontal bedding, the dips being as a rule greater and more variable
the nearer one approaches to the watershed mountain-ranges. These
tectonic disturbances, which are important in connexion with the
geological history of the region, will be considered in Chapter XI.
* * * * *
[Footnote 122: _Geol. Mag._, Decade V, Vol. VI (1909), p. 271.]
[Footnote 123: The numbers in square brackets are the specimen-numbers
in the Cairo Geological Museum.]
[Footnote 124: Wadi Abu Rahal is a small feeder of Wadi Abad,
joining the latter from the south in latitude 25° 0′, longitude
33° 30′. At the point of junction of the two wadis, which lies
on the usual camel road from Edfu to the Baramia mine, a well was
sunk by the Mines Department in 1906, in the hope of obtaining a
water supply. I visited the well in May 1906, when it had attained
a depth of fifty-four metres. The strata passed through were ten
metres alluvium, then thirty-seven metres of sandstones and clays,
followed by a thin band of bituminous shale, and seven metres of
dark grey clays. From near the bottom of the well I collected
specimens of _Lingula_ and a mytiloid shell which Mr. Bullen
Newton compared to _Septifer linearis_; the latter shell differs
but little from specimens obtained from the English Gault, and thus
tends to show that the Abu Rahal beds are of Cretaceous age. (_See_
HUME, _Preliminary Report on the Geology of the Eastern Desert
of Egypt_. Cairo, 1907. p. 29). Since my visit, the well has been
deepened to seventy-three metres in sandstones with a bituminous seam,
but water was not reached, and the well has been abandoned.]
CHAPTER IX.
* * * * *
=IGNEOUS ROCKS.=
* * * * *
Igneous rocks cover about one-third of the entire area of
South-Eastern Egypt, forming irregularly distributed tracts,
alternating with others occupied by metamorphic rocks, entering
largely into the composition of the principal mountain masses and
also underlying a large portion of the areas covered by sand on the
coast-plain and elsewhere.
Regarded broadly, the igneous rocks of this portion of the Eastern
Desert form two main divisions, namely, an _acid_ division typified
by granite rich in felspar, and a _basic_ division typified
by gabbro. Intermediate types occur, as well as ultra-acid and
ultra-basic rocks, but these are less abundant, and are generally
found in close association with one or other of the two main
types. Rocks of the acid type predominate to the north of latitude
24°, while further south basic rocks form large portions of the main
mountain tracts, with acid rocks at intervals on either side down to
the Sudan frontier. Most of the igneous rocks are plutonic. There
is a striking paucity of volcanic rocks, a circumstance doubtless
to be ascribed largely to the enormous denudation which has taken
place in the district. The plutonic masses, with the dykes seaming
them, have been elevated and laid bare, while most of the volcanic
outpourings have been denuded away and others have been altered
or devitrified till their original volcanic nature has become less
apparent. Metamorphism has also affected many of the plutonic masses
to such a degree that it is often difficult to decide whether the
rocks should now be placed in the igneous group, or classed as
metamorphic rocks.
For purposes of classification, the igneous rocks of
South-Eastern Egypt may be divided into five main groups, based
on silica-percentage:—
1. _Ultra-acid rocks_, containing over 80 per cent of silica.
2. _Acid rocks_, containing from 65 to 80 per cent of silica.
3. _Intermediate rocks_:—
(_a_) _Sub-acid rocks_, with from 60 to 65 per cent of silica.
(_b_) _Sub-basic rocks_, with from 55 to 60 per cent of silica.
4. _Basic rocks_, containing from 45 to 55 per cent of silica.
5. _Ultra-basic rocks_, with less than 45 per cent of silica.
The classification is based on silica percentage, for although
up to the present it has not been found possible to undertake the
chemical analysis of the rocks, the microscopic examination of thin
sections itself gives a very fair guide to the chemical composition,
and the specific gravities of the different rocks, which increase
progressively from the acid to basic groups, afford a further guide
in this direction. The table on the following page shows the different
rocks comprised within the five main classes.
The five classes are not all of equal importance. As already
mentioned, the acid and basic types are predominant. The ultra-acid
and sub-acid rocks are present in relatively small quantity, and are
in close relationship with those of the acid series which occur in
great abundance; the rocks of the sub-basic and ultra-basic groups,
on the other hand, though by no means insignificant in their
distribution (diorites and serpentines cover very large areas),
appear to be closely linked in the field with those of the basic
group. The district is so large, and the investigation of it has been
so limited, that it would be unwise to draw from the above remarks
the deduction that the rocks have originated from two main magmas;
the statements are merely those of the facts of observation, so far
as observation has proceeded.
The scheme tabulated above differs from established classifications
only in the inclusion of an _ultra-acid_ class of rocks. This
inclusion is necessitated by the presence in the district of
huge masses of quartz-rocks which are almost certainly igneous
in origin. These rocks are almost pure silica, and though they
are properly regarded as an extreme form of pegmatite, their
silica-percentage (over 95) is too high for them to be placed with
their near relations the granites; and on grounds of symmetry of
classification it appears justifiable to have an “ultra-acid”
class corresponding with that of ultra-basic rocks.
CLASSIFICATION OF IGNEOUS ROCKS.
--------+------------+-----------------------+-----------+--------------
| | Intermediate. | |
Ultra- | Acid. | | Basic. | Ultra-basic.
acid. | +----------+------------+ |
| | Sub-acid.| Sub-basic. | |
--------+------------+----------+------------+-----------+--------------
_Quartz-|_Granite_ |_Syenite_ |_Diorite_ |_Gabbro_ |_Pyroxenite_
rock_ | | | | |
| | | | |
| Normal pink| | Augite- | Troctolite|_Amphibolite_
| granite | | diorite | |
| | | | |
| Red | | Mica- | Pyroxene- |_Peridotite_
| pegmatitic | | diorite | granulite |
| granite | | | |
| | | | |
| Aplite | | | |_(Serpentine)_
| | | | |
| Biotite- | | | |
| granite | | | |
| | | | |
| Muscovite- | | | |
| granite | | | |
| | | | |
| Hornblende-| | | |
| granite | | | |
| | | | |
| | | | |
|_Granite- |_Syenite- |_Diorite- |_Diabase_ |
|porphyry_ |porphyry_ |porphyrite_ | |
| | | | |
| | | Augite- | Mica- |
| | | porphyrite | diabase |
| | | | |
| | | Kersantite | |
| | | | |
| | | | |
|_Quartz- |_Trachyte_|_Andesite_ |_Basalt_ |
|felsite_ | | | |
--------+------------+----------+------------+-----------+--------------
ULTRA-ACID ROCKS.
=Quartz-rock= of igneous origin occurs in the form of intrusive
bosses and veins penetrating older igneous and metamorphic rocks
at Marwot Elemikan and elsewhere. The rock is practically pure
vitreous quartz. Its dazzling white aspect in the sun renders it very
conspicuous in the field. The shape of many of the masses (bosses),
their close association with pegmatite and aplite in at least one
locality, the absence from the veins of other minerals (calcite and
various ores) such as usually accompany vein-quartz deposited from
solution, and the occasional presence in the rock of mica flakes,
all point to an igneous origin, and justify us in regarding this
quartz-rock as the final product of differentiation of a granitic
magma, representing its ultra-acid portion.
The most conspicuous occurrence of quartz-rock is in the three
nearly conical hills called Marwot[125] Elemikan, which rise from the
granitic plain at the head of Wadi Elemikan in latitude 23° 53′,
and which from their snow-white colour form landmarks visible from
great distances. The largest and most northerly hill of the three is
a boss about 300 metres in diameter, rising sixty-eight metres above
the plain, which itself has here an altitude of 580 metres above
sea. The other two hills are somewhat smaller; they lie respectively
two kilometres south-east, and two and half kilometres south, of the
largest one; a black hill of about equal size rises from the plain
mid-way between them. The highest of the three white hills, which was
occupied as a triangulation station, is composed almost entirely of
glassy quartz, the only other mineral seen in it being a white mica,
of which a few flakes were visible in the outer portions. The mass
is cracked in all directions, and the faces of the separated blocks
frequently show a slight yellowish staining.
Another remarkable boss of quartz, similar to that just described
and likewise rising through granite, occurs on the south side of the
Wadi Khoda (latitude 23° 42′) about seven kilometres above the
point where the wadi emerges from the hills on to the coast-plain. A
third occurrence, of much less size, in the floor of Wadi Abu Marwa,
on the track from Wadi Lahami to Berenice _via_ the Wadi Naait;
the first-mentioned wadi derives its name from the quartz occurrence
in it.
Of igneous quartz veins, the best example is the huge dyke which forms
the back-bone of the ridge called Erf el Fahid, in latitude 25°
0′. Here the vein, which strikes east and west, is in schistose
country. It is at least ten metres wide, rising to a height of
ninety-five metres above the wadi, and can be traced for a length of
nearly two kilometres. Like the rock of Marwot Elemikan, the quartz
of Erf el Fahid shows faint iron-staining in places, but appears to
contain no other minerals. It is weathered to a sintery appearance
in places [10,362],[126] and contains some cavities, from one of
which I extracted a handful of loose quartz crystals [10,363] with
pyramids developed at both ends; these last are evidently deposited
from solution, but it is difficult to assign other than an igneous
source for the vein, and the cavities and loose crystals are probably
the product of solution subsequent to the igneous intrusion.
Going south-west from Erf el Fahid, down the Wadi Muelih, is
another line of ridges, of which the back-bone is a great quartz vein
traceable for some two and a half kilometres along its strike. Further
down the wadi are networks of quartz veins seaming diorite in all
directions on either side of a horse-shoe-shaped hill called Marwot
Rod el Ligaia; this hill is of aplite, and probably represents a
less acid part of the same magma which formed the quartz veins.[127]
It is significant that there are no traces of mine workings at any of
the places where quartz veins and bosses of the igneous type occur,
notwithstanding the fact that the masses are so conspicuous as to have
surely attracted the eye of every gold-seeking prospector. Though
the loose crystals found at Erf el Fahid show that there at least
aqueous solutions have acted on the rock to a slight extent, these
great igneous quartz masses appear never to have been impregnated
with gold or other ores.
ACID IGNEOUS ROCKS.
=Granites.=
Granites are the most abundant and most widely distributed of the
igneous rocks of South-Eastern Egypt. They form a large proportion
of the most prominent mountain masses, such as Gebels Hamrat Wogud,
Nugrus, Hamrat Mukbud, Hamata, Faraid, Um Reit, Mishbih, Adar Qaqa,
Adar Aweib, and Elba. They also occur in some great plain tracts,
such as those round Gebel Selaia and to the west of Gebel Um Reit,
where low hills of the rock rise through the coarse granitic sand
which covers most of the plain.
In point of geological age, the granites appear to be the youngest
of the plutonic rocks of the country, forming great intrusions in
the more ancient schists and diorites.
Though sometimes occurring as rounded bosses, as at Gebels Muelih,
Selaia, and Faraid, granite typically forms rather jagged mountains,
more especially in the south parts of the area; the mountains of
Mishbih and Elba, for instance, abound in spiky peaks, while Qash
Amir, the “Scragged Hill” of the Admiralty Chart, is an extreme
example of this mode of weathering. The spikes are often made up
of more or less rounded blocks piled one on another, the separation
and rounding of the blocks being brought about by jointing and the
more rapid weathering of the corners of the separated masses. Granite
mountains, though sometimes white, are usually of a pink or red colour
and are often named accordingly by the Arabs. In Ababda country, all
mountains named _Hamrat_, as for instance Hamrat Wogud and Hamrat
Mukbud, are composed of red granite or granitoid gneiss; while in
Bisharin country the corresponding name _Adar_, as used for example in
Adar Qaqa and Adar Aweib, has the same significance, both the names
meaning _red_. The beds of wadis draining from granitic mountains,
and plains adjacent to them, are invariably covered with a thick
accumulation of coarse felspathic and quartzose sand derived from the
weathering of the rock. This sand is quite firm to walk on, and in
this respect forms a pleasing contrast to the finer wind-borne sand
derived from the disintegration of sandstone. The granitic sand being
generally white in colour (the redness of the felspars having largely
disappeared in the process of weathering), the wadis in whose floors
it is largely displayed are frequently named “Wadi el Abiad”
(_abiad_ = white); there are numerous wadis called by this name,
all possessing the common characteristic of draining from granitic
mountains and consequently having a floor of granitic sand.
Besides the great mountain-forming masses, granites also occur
frequently in the form of dykes or veins, penetrating the gneisses,
schists, and other rocks.
Viewed as a whole, the granites of South-Eastern Egypt are
characterised by their strongly acid composition. Though perfectly
normal granites are found in many places, and a gradual passage
into quartz-syenite may be occasionally traced, yet on the whole
the rocks approximate to the aplitic and pegmatitic types in which
quartz and felspar are associated with very small quantities of
ferro-magnesian minerals.
We may consider the granites as falling mainly into the following
classes:—
1. Normal pink granite.
2. Red pegmatitic granite.
3. Aplite.
4. Biotite-granite.
5. Muscovite-granite.
6. Hornblende-granite.
=PLATE XXII.=
[Illustration: Ball.—Geography & Geology of South-Eastern Egypt.
=ACID IGNEOUS ROCKS.=
=PORPHYRITIC GRANITE.= Gebel Fereyid.
=PEGMATITIC RED GRANITE.= Wadi Gemal.
=BIOTITE-GRANITE.= Gebel Abu Hegilig.
=HORNBLENDE-GRANITE.= Gebel Elba.
=QUARTZ-FELSITE.= Near Gebel Kolaiqo.
=QUARTZ-FELSITE.= Near Gebel Kolaiqo.
NATURAL SIZE.]
=Normal pink granite= is the form of granite most commonly met with
in South-Eastern Egypt. It forms the principal rock of many of the
mountains, such as Gebels Nugrus, Selaia, Faraid, Um Reit, Shigigat,
Niqrub, Abu Brush, and Hamra Dom, and also covers large expanses of
low hill country, and occurs as knolls scattered over sandy plains
such as that of Selaia and the tract west of Um Reit. The rock
[11,505], a full size representation of which is shown on Plate
XXII, is composed of pink orthoclase, white oligoclase, quartz,
and biotite, with hornblende, sphene, apatite, and magnetite as
accessory minerals. The pink orthoclase is the dominant constituent,
and gives the colour to the mass; it is sometimes in grains of about
the same size as those of the quartz, _viz._, two to four millimetres
in diameter, but frequently tends to assume a porphyritic habit, the
crystals then measuring a centimetre or more across, and inclining to
idiomorphic forms. Microcline is occasionally sparingly present. The
oligoclase is white, and is far less abundant and less conspicuous
than the orthoclase; in the porphyritic varieties of the rock,
the oligoclase is mixed with the quartz and mica of the ground
mass. In some specimens the felspars are fresh, in others [12,133]
they show clouding due to decomposition, with formation of kaolin
and occasionally of sericite. Quartz is present to about half the
amount of the felspars, in grains ranging up to three millimetres in
diameter. The biotite is frequently the only ferro-magnesian mineral
present, occurring in wisps and little nests among the other minerals;
under the microscope it is strongly pleochroic, the colour varying
from usually a pale olive brown to nearly black when a crystal is
rotated over a nicol prism, though in a specimen [11,531] from the
little hill called Sikeit, about five kilometres west of Berenice,
colour range is from pale yellow to deep green. Hornblende is
typically either absent or present only in a very subordinate amount
to the biotite. It is sometimes altered to chlorite, with separation
of granules of iron oxide and formation of epidote. Sphene, apatite,
and magnetite are usually only very sparingly present, and are only
visible on microscopic examination. In a slide cut from the rock
of Gebel Fereyid, however, sphene forms a crystal measuring 1·6
millimetres across, of the characteristic wedgelike form (_see_
Fig. 4).
[Illustration: Fig. 4.—Granite, Gebel Fereyid [11,505], × 10. _f_,
felspar (mostly orthoclase), somewhat clouded by decomposition; _q_,
quartz; _b_, biotite; _s_, sphene.]
The principal variation in mineral composition of the rock is the
greater or less abundance of the biotite, and the occasional presence
of appreciable amounts of hornblende. In a specimen from Wadi Kreiga
[12,133], the biotite is almost absent, its place being taken by
green hornblende, now largely altered to chlorite and epidote. The
ferro-magnesian minerals are as a rule present in smaller amounts
than in average granites, and in some places, especially near the
periphery of the great intrusions, they vanish almost entirely,
and the rock passes gradually into a pegmatite.
Variations in appearance of the rock are also conditioned by the
size and habit assumed by the felspar crystals, by the variations
in general coarseness or fineness of grain, and by the pressures and
weathering influences to which the masses have been subjected. Where
the rock has been crushed, or subjected to unequal pressures in
different directions during consolidation, the porphyritic crystals
tend to lie along definite planes, and the rock may approximate in
appearance to a gneiss. The microscopic sections from these places
show further evidence of crushing in the cracking of crystals
and undulose extinction between crossed nicols. Where the rock
is much weathered it usually takes on a whiter aspect due to the
bleaching of the orthoclase, and sometimes exhibits green spots
due to the formation of chlorite from the decomposition of biotite
and hornblende.
It is the pink granite which by its disintegration gives rise to much
of the granitic sand which is met with in wadis and on plains. The
rock disintegrates very readily under changes of temperature, the
cleavage planes of the orthoclase aiding in the process. Change
of the felspar to kaolin goes on under weathering influences, and
the felspars become bleached, but the bulk of the disintegration
is a mechanical process, a large part of the sand consisting of
unaltered felspar.
=Red pegmatitic granite= is closely associated with the normal pink
granite, occurring in great masses peripherally to the latter, as for
instance at Gebel Hamrat Mukbud and in the low hills about the lower
parts of Wadi Gemal and Wadi Kreiga. The red pegmatitic granite is in
fact simply an extreme variation of the normal pink granite in which
the ferro-magnesian minerals (biotite and hornblende) are either
absent or present in very small amounts. That the rock often forms
dykes is probably a consequence of its peripheral position rather
than of any special manner of formation. The great masses such
as Gebel Hamrat Mukbud appear, like the normal granites, to have
solidified under plutonic conditions, and the dykes are off-shoots
from the main mass. There is, therefore, no reason in this locality
for classifying the pegmatites separately from the granites into
a special division of dyke-rocks, as is done by Prof. Rosenbusch,
and we shall consider the red pegmatitic granite as simply a coarse
grained mica-free granite rich in orthoclase.
The pegmatitic granite is usually of a far more pronounced red
colour than the normal granite. This is doubtless in part due to the
greater abundance of orthoclase, but it also arises in some cases
from the orthoclase having itself a deeper colour. The rocks about
the lower parts of Wadi Gemal and Wadi Kreiga have a strong brick-red
aspect. Their proximity to the coast suggests that there may possibly
be some connexion between the intensity of their coloration and
their position near the sea; this idea is supported in some measure
by the strong red colouration of the dioritic rocks of Ras Benas,
which occupy a similar position, but the actual manner of production
of the oxide of iron which gives the colour is not clear.
[Illustration: Fig. 5.—Red pegmatitic granite, from low hills
near the mouth of Wadi Gemal [12,106], × 10. _q_, quartz; _f_,
felspar (orthoclase) turbid and full of finely disseminated red
oxide of iron.]
In the hand specimen (_see_ Plate XXII), the red pegmatitic granite
[10,389] is a coarse-grained aggregate of red orthoclase and
quartz. The quartz is generally of grey aspect in the mass, running
in strings and networks through the felspar. The rock usually breaks
easily into irregular pieces under the hammer, owing to the facility
with which the large felspar crystals can be cleaved, but the very
red variety from near the mouth of Wadi Gemal [12,106] is extremely
hard and tough, and strikes fire very easily under the hammer. Under
the microscope (_see_ Fig. 5) the red colour of the orthoclase often
persists even in the thinnest sections, being evidently due to finely
disseminated iron oxide which clouds the felspars. The quartz shows
sharply defined angular forms, and appears to have got somewhat the
start of the felspar in crystallisation. Owing to its cloudy nature,
the felspar looks like a ground mass, and between crossed nicols shows
a peculiar patchy appearance, so that a first glance at the slide
suggests a quartz porphyry; but the whole of the patches forming a
crystal extinguish at once, and moreover the characteristic twinning
of the orthoclase can be seen in some of the crystals. A little
oligoclase is also present in addition to the orthoclase. Crushing
of the rock is frequently shown by cracked and brecciated crystals,
more especially in the hard form of the rock from Wadi Gemal.
Dykes of pegmatitic granite are very frequent in the neighbourhood
of Gebel Hamrat Mukbud; they are typically rather paler in colour
than the larger masses, and occasionally show graphic structure.
In ascending Gebel Migif, the gneiss slopes of the mountain were
found to be strewn here and there with crystals of green microcline
[10,366], similar to the well-known Pike’s Peak mineral. The
crystals, which are of imperfect idiomorphic form, measuring about
one to two centimetres in length, sometimes show cross-striations on
certain faces. Though the rock was not traced _in situ_, the crystals
are doubtless derived from pegmatite dykes traversing the gneiss.
=Aplite=, or fine-grained binary granite consisting essentially
of quartz and felspar, with very little or no mica or hornblende,
differs from pegmatite not only in its greater fineness of grain,
but in its structure, which is essentially granitic rather than
pegmatitic, the two main minerals being both in allotriomorphic
grains. In colour, different aplites vary with that of their felspars
from red to white, and most of them have tiny dark spots in them,
sometimes only visible with a lens, due to the presence of small
quantities of hornblende or biotite. As already mentioned on p. 268,
most of the granites of South-Eastern Egypt incline to the acid or
aplitic type, and one is frequently in doubt whether to classify an
acid granite, such as that of Gebel Elba for instance, as an aplite
with a little hornblende, or as a hornblende granite. Under aplites
will be here considered only those granites in which the proportion of
ferro-magnesian minerals is extremely small, not forming more than
about one or two per cent of the rock. When the definition of an
aplite is thus limited, aplites are comparatively scarce in the area.
Gebel Abu Hireiq consists of a red granitic rock; I did not visit
the range, but the guide sent to erect the triangulation beacon
brought back as the typical rock a pink aplite [12,134] of rather
fine grain, consisting essentially of quartz and pink felspar,
with sparsely scattered specks of hornblende.
The dykes [11,536] which seam the granite and diorite near where
the Wadi el Kreim joins Wadi Garara may be classed as siliceous
altered aplites. They are greyish-white to purplish-pink rocks of
rather fine grain, with a few blackish specks, the latter visible
only with a lens. The microscopic slide shows granitic quartz and
red-stained decomposed matter, with a rather plentiful sprinkling
of grains and powder of iron oxide; the decomposed matter is almost
certainly the result of alteration of felspar and hornblende, the
latter in very small proportion.
The hill called Marwot Rod el Ligaia, near the head of Wadi Muelih, is
a boss of pink aplite, and is of interest as lying in close connexion
with certain quartz veins which are believed to be of igneous origin
(_see_ p. 266).
[Illustration: Fig. 6.—Biotite-granite near Gebel Abu Hegilig
[10,390], × 17. _q_, quartz; _f_, felspar (orthoclase and
oligoclase), somewhat turbid by decomposition; _b_, biotite; _s_,
sphene.]
=Biotite-granite= of a well-defined type [10,390] occurs somewhat
largely in the mountains round the heads of Wadi Abu Ghusun and Wadi
el Abiad. It is a whitish rock with dark-brown to black spots (_see_
Plate XXII). The white portion of the rock consists of quartz and
felspar; the dark spots are biotite. Generally the rock is of medium
grain, the biotite being in nests two to four millimetres diameter
scattered through the mass, giving it a speckled appearance. Sometimes
the biotite is more uniformly scattered, giving the rock a grey
aspect. At some places the rock shows signs of crushing, this being
indicated in hand specimens by a tendency to laminar arrangement
of the biotite patches. Under the microscope (_see_ Fig. 6), the
felspars, which are somewhat more abundantly present than the
quartz, are seen to consist of orthoclase and oligoclase, with
here and there crystals showing the characteristic cross hatching
of microcline. The biotite is mostly in nests and clusters of
ragged-looking crystals, but it also occurs in tiny flakes included
in the felspars, sometimes showing a distinct arrangement along the
cleavage planes of the latter. The biotite is usually fairly fresh;
it is highly pleochroic, with colour ranging from pale yellow to deep
olive-green in different positions over the nicol. Associated with the
biotite are a few wisps of colourless mica, probably muscovite, and
irregular granules of opaque iron oxides. Granules of epidote are to
be seen in the altering felspars, and there are a few small irregular
granules of a brownish highly refracting mineral, probably sphene.
A much more acid type of biotite granite [11,507] occurs in close
proximity to serpentine in low hills near the wells of Abraq. In this
the proportion of biotite is so small that the rock might almost
be classed as an aplite. It is a fine-grained white rock, very
fresh-looking, with dark spots; in hand specimens it almost exactly
resembles the hornblende granite of Gebel Elba (_see_ Plate XXII),
but examination with a lens shows the dark spots to consist of biotite
instead of hornblende. The microscopic slide shows quartz, orthoclase,
and oligoclase with granitic structure, with here and there small
straggling crystals of brown biotite; the brown biotite is sometimes
altering to chlorite with change of colour from brown to green.
=Muscovite-granite= is rarely met with in South-Eastern Egypt. A
specimen from Gebel Adar Qaqa[128] [12,138] is a fine-grained hard
pinkish rock of sp. gr. 2·62, composed of quartz, orthoclase,
oligoclase, muscovite, and garnet.
A very coarse-grained variety of muscovite-granite, in which the
individual crystals measure several centimetres across, forms white
hills to the east of Wadi Nugrus.
=Hornblende-granite= occurs in several forms, giving rise to rocks
of different aspects in different parts of the district.
The most important and widely distributed form of hornblende-granite
is a fine-grained and very acid rock of sp. gr. 2·59, which but
for the manner in which it occurs might almost be spoken of as an
aplite. It is a white rock, sometimes with a faintly pink or greenish
cast, of medium to fine grain, with black specks of hornblende about a
millimetre in diameter scattered through it (_see_ Plate XXII). This
rock forms Gebels Muelih and Elba; it also occurs in the low country
round Gebel Hamrat Mukbud, and a gneissose variation of it forms
the great boss of Um Rasein. Dykes of the same rock traverse the
more basic rocks of Um Bisilla.
[Illustration: Fig. 7.—Hornblende-granite, Gebel Elba [12,118],
× 17. _q_, quartz; _f_, felspar (mostly orthoclase), clouded by
kaolinisation; _h_, hornblende; _b_, biotite, altering with separation
of flakes of limonite.]
Under the microscope the rock from Gebel Elba [12,118] is seen to
consist of quartz, orthoclase, a little oligoclase, hornblende, and
small quantities of biotite (_see_ Fig. 7). The orthoclase is somewhat
clouded in strips parallel to the clino-axis of the crystals. The
hornblende is in irregular grains of sharply marked curved outlines;
it is of a very deep bottle-green colour. The accessory biotite is
brown, occurring as small wisps associated with the hornblende.
The rock of Gebel Muelih [10,355] is similar to that of Gebel Elba,
but the hornblende here is of an extremely pale greenish brown colour,
only slightly pleochroic, with well-marked vertical cleavage and a
very small extinction angle, so that it might be mistaken for biotite,
which latter mineral appears to be absent.
[Illustration: Fig. 8.—Hornblende-granite, Gebel Hamata [10,405],
× 10. _q_, quartz (the rock contains a larger percentage of quartz
than appears in the drawn portion of the slide); _f_, felspar
(orthoclase), clouded; _h_, hornblende, altered.]
Another type of hornblende-granite, differing from that last
described in being of coarser grain and containing much more abundant
hornblende, and thus having much more the appearance of an ordinary
grey granite, occurs in the lower part of Gebel Hamata and the
surrounding mountains. This rock [10,405] is slightly heavier than
the foregoing type, having a sp. gr. of 2·66. Under the microscope
(_see_ Fig. 8) the hornblende is seen to be of a dark green colour,
very much altered and clouded by separated iron oxides and epidote.
A third type of hornblende-granite is formed by the variation of
the normal pink granite already referred to, in which the place of
biotite is largely taken by hornblende. The mass of Gebel Mishbih
appears[129] to consist of a rock of this type, which passes by
insensible gradations into a syenite.
=Granite-porphyry.=
[Illustration: Fig. 9.—Granite-porphyry, Kreishim Hill [12,150],
viewed between crossed nicols, × 10. _q_, quartz (the dark triangular
area to the left of figure is also a quartz crystal in the position
of extinction); _f_, felspar (oligoclase); _g_, micro-granitic
ground mass.]
Under this heading are comprised rocks of granitic composition in
which porphyritic crystals of quartz, felspar, and mica are surrounded
by a fine-grained ground mass of entirely granitic (holocrystalline)
character. They differ from porphyritic granites in the much finer
grain of the general body of the rock, and from the quartz felsites
in the entire absence of glassy matter from the ground mass. Rocks
of this type are scarce in South-Eastern Egypt. An example [12,150]
occurs at the hill called Kreishim, sixteen kilometres west of
Halaib. Here the rock, which appears to form a small boss, consists
of rounded white porphyritic crystals set in a finely crystalline
grey ground mass. The sp. gr. is 2·69. Under the microscope (Fig. 9)
the porphyritic crystals are seen to consist of quartz and oligoclase,
the latter in approximately idiomorphic crystals, often beautifully
zoned; the ground mass, of micro-granitic structure, is made up of
smaller allotriomorphic crystals of quartz, felspar, and biotite.
Dykes of granite-porphyry also occur traversing the granite of
Gebel Kahfa [11,537 B] and in the basic rocks of Gebel Um Bisilla
[11,518]. At both these places the rocks are far less fresh than that
above described. In the hand specimen they are of a greyish-white
or greenish-white colour, strongly resembling fine-grained aplites
in appearance. With the lens, crystals of quartz and felspar can be
made out, and specks of hornblende and chlorite. The microscopic
slides show the characteristic structure of granite porphyry, but
the felspars are all clouded by decomposition products, and the
hornblende, which is rather sparingly present in the ground mass,
is mostly changed to chlorite and epidote. The specimen from Gebel
Kahfa contains a small amount of muscovite.
=Quartz-felsite.=
Though covering only small areas, quartz-felsite is of very wide
distribution in South-Eastern Egypt. It typically forms dykes and
intrusive sheets traversing the plutonic and metamorphic rocks,
but likewise occurs occasionally in larger masses. Felsite dykes
are specially abundant in the neighbourhood of Gebels Muelih,
Zergat Naam, and Um Reit. Larger masses occur in the Wadi Huluz,
and form the summits of Gebels Nigrub el Foqani and Hamata.
Felsites are frequently met with in a highly altered condition. The
commonest alteration, especially in dykes, is kaolinisation of the
felspars and a clouding of the whole rock with finely disseminated
iron oxides. In some dykes traversing the granite of Um Reit,
a bleaching action has reduced the felsite to the appearance
of a limestone. In other cases the rock has been devitrified and
indurated to a high degree; this is well seen in Gebel Igli el Iswid
(latitude 25°) and at Gebel Hadarba (latitude 22°), where extensive
hill-tracts consist of felsitic rocks of almost flinty hardness.
The quartz-felsites are in general among the youngest of the igneous
rocks of the district, since they commonly form dykes and intrusions,
not only in the schists, but also in the granites and other eruptive
rocks.
[Illustration: Fig. 10.—Quartz-felsite, Wadi Huluz [10,394],
× 10. _q_, quartz; _f_, felspar (orthoclase and oligoclase); _g_,
ground mass, showing flow structure round the porphyritic quartz
and felspar.]
The quartz-felsite of Wadi Huluz [10,394] occurs in considerable
masses about a kilometre below the water holes of Um Gerifat. In
the hand specimen, it is of granitoid appearance, with opalescent
quartz crystals two millimetres or more in diameter plentifully
scattered in a light greyish ground mass. The sp. gr. is 2·71. Under
the microscope the crystals of quartz are seen to have rounded
forms and to be accompanied by other porphyritic crystals of
orthoclase and oligoclase, often approximating to idiomorphic shape
(_see_ Fig. 10). The porphyritic constituents are embedded in a
cryptocrystalline ground mass, in which augite and minute grains of
quartz, felspar, and biotite can be made out, and there are some
strings and granules of epidote and fairly large specks of iron
oxides. The ground mass shows a fluidal arrangement, the little
biotite flakes in it being often arranged in lines which sweep
round the porphyritic crystals. The rock has undergone considerable
alteration, the felspar crystals being clouded and full of tiny
micaceous flakes of high double refraction; the epidote is also
doubtless due to the alteration of augite and other minerals in the
ground mass.
The quartz-felsite which forms the upper part of Gebel Hamata
[10,906] is a dark brown coarse-textured rock, with remarkably
glassy porphyritic quartz in granules about two millimetres diameter
scattered plentifully through it. It is a very hard rock which rings
under the hammer and weathers into rusty brown blocks. The sp. gr. is
2·71. Under the microscope the quartz crystals are seen to be
much cracked. There are also porphyritic crystals of orthoclase and
oligoclase, mostly of irregular shape, and a few crystals, of still
more irregular form, of dark green hornblende. The cryptocrystalline
ground mass consists chiefly of quartz and felspar, through which are
scattered tiny granules of dark green hornblende. The ground mass
shows a matted texture between crossed nicols; there is no trace
of fluidal movement. Like the foregoing, this rock is somewhat
altered, the hornblende in particular being very much attacked;
the felspars are fairly fresh, but the crystals, like those of the
quartz, are often cracked, and thus show the rock to have undergone
considerable crushing.
[Illustration: Fig. 11.—Quartz-felsite from dyke at Gebel Kolaiqo
[12,145], × 10. _q_, quartz (a group of idiomorphic crystals); _f_,
felspar (mostly orthoclase); _g_, microgranitic ground mass of quartz
and felspar, with wisps of hornblende.]
One of the quartz-felsite dykes traversing the schists at Gebel
Kolaiqo [12,145] is a very similar rock to that of Gebel Hamata, except
that here the ground mass, instead of being dark brown in the hand
specimen, is of a reddish brown colour (_see_ Plate XXII), and
the porphyritic crystals are partly pink felspar and partly glassy
quartz. The sp. gr. is 2·62. Under the microscope the quartz and
felspar crystals are seen to be less crushed than in the Hamata
rock, while the ground mass, instead of being of a matted structure,
is microgranitic, with tiny elongated grains of green hornblende
scattered through it (_see_ Fig. 11).
Another quartz-felsite dyke at Gebel Kolaiqo [12,135] has a rather
different composition, and in the hand specimen has more the
appearance of a felspar porphyry, porphyritic white felspars being
scattered with quartz grains through a dark grey to black ground mass
(_see_ Plate XXII). Its quartz crystals frequently approximate to
idiomorphic forms; they are much corroded by the ground mass. The
felspar is chiefly oligoclase, in more or less idiomorphic crystals, a
little clouded by decomposition products. The ferro-magnesian mineral
here is chiefly brown biotite, in crystals of smaller size than
those of the quartz and felspar, scattered porphyritically through
the ground mass. One of the quartz crystals includes a crystal of
biotite. The ground mass is crystalline, and appears to consist of
quartz and felspar with a little biotite and some glassy matter.
A peculiar type of quartz-felsite [10,377] occurs associated with
serpentine and ophicalcites in the upper part of Gebel Ghadir. The
rock, which has a sp. gr. of 2·66, is nearly white, with a faint
greyish tinge and scattered reddish-brown specks. At first the
rock was taken for a granulite, which it very much resembles in
appearance, and the reddish-brown specks for garnet. But examination
with a lens shows the specks to be ferric oxide, and here and there
little crystals of glassy quartz can be seen. Under the microscope
the rock is found to consist mainly of an extremely fine-grained
semi-granulitic colourless ground mass in which are sparsely
scattered clear crystals of quartz, sometimes showing corrosion,
and straggling irregular patches of opaque iron oxide, often mixed
with nearly colourless wisps of mica. A few of the clear crystals
are in four-sided forms, and may possibly be felspar; but they
are perfectly free from alteration or twinning. The iron oxide is
doubtless the product of alteration of a ferro-magnesian mineral,
probably biotite. The minerals of the ground mass are difficult
of determination owing to the minuteness of the grains and the
absence of any colour, but apparently consist of quartz, felspar,
a colourless hornblende, and sericite.
The quartz-felsite dykes [10,356] which cut through the granite and
schists of Gebel Muelih appear as grooves in the granite, and as
back-bone ridges in the surrounding schists. They are pinkish-brown
close-textured rocks, with a dark marbling in places. The microscopic
slides show quartz and felspar in a confused ground mass, with
little flakes of a white micaceous mineral (sericite?) aggregated
round the porphyritic crystals and distributed through the felspars
and the ground mass.
The highly altered quartz-felsite [12,158] which forms Gebel
Butitelib, near Gebel Niqrub el Tahtani, appears to have formed
a boss or neck in the surrounding schists. The rock is a very
fine-grained grey to purplish one, in which no crystals can usually
be made out with the unaided eye. The sp. gr. is very low, being
only 2·32. Under the microscope one sees small highly corroded
crystals of quartz scattered through a clouded and glassy ground
mass. No traces of felspars can be seen, the crystals, if they
existed, having been decomposed and become undistinguishable from
the ground mass; nor can any ferro-magnesian minerals be made out,
though there are tiny granules and wisps of iron oxides which in
places show an arrangement suggestive of their having been derived
from the decomposition of such minerals.
The specimen [12,121] brought back from the summit of Gebel Shendib,
by the guide who was sent to erect the triangulation beacon on
it, is a compact brown rock with reddish patches, which under the
microscope appears to be an altered and brecciated felsite.[130]
The slide shows quartz and altered felspars in a spherulitic ground
mass, the whole of the mineral being very much clouded by finely
disseminated ferric oxide.
The felsite dykes [11,538] which seam the granite of Gebel Um Reit are
a still more highly altered rock. The dykes are about two metres wide,
of a white colour, and resemble limestone in appearance; being soft,
they have weathered more rapidly than the granite around them, leaving
vertical-sided chasms. But for the manner of its occurrence, the
rock would have been easily mistaken in the field for a sedimentary
one. The microscope, however, confirms its eruptive origin. The
slides cut from the rock show a confused and clouded semi-crystalline
aggregate, containing clearer small areas of quartz. Even the quartz
crystals are full of specks, and only the faintest traces can be seen
of the felspars, which are so decomposed as to be hardly distinguishable
from the ground mass.
[Illustration: Fig. 12.—Altered quartz-felsite, Gebel Igli
el Iswid [10,372], as seen between crossed nicols, × 40. _f_,
felspar (mostly orthoclase in the position of extinction); _h_,
a crystal of hornblende; _g_, hemi-crystalline ground mass; _m_,
micropegmatitic intergrowth of quartz and felspar, separating the
porphyritic crystals.]
In the rocks of Gebels Igli el Iswid, Mahali, and Hadarba, we
have quartz-felsites which have been altered in quite a different
way. The rocks are extremely hard, and almost flinty, breaking with a
sub-conchoidal fracture. They are typically of a brown to nearly black
colour, with white spots measuring a millimetre or two across. Under
the microscope these white spots are seen in the rock from Gebel
Igli el Iswid [10,372] to be chiefly porphyritic felspar and quartz
crystals, sometimes corroded by the ground mass; while the black
ground mass is largely composed of extremely fine micro-pegmatitic
intergrowths of quartz and felspar, with some glassy matter,
and here and there irregular small clouded and altered crystals of
hornblende. The micro-pegmatitic material has possibly originated by
devitrification of an originally glassy ground mass. Variations of
the rock occur in which the porphyritic felspars are infrequent or
even altogether absent, the rock passing gradually into a hornfels
[10,371]. The slide from Gebel Mahali [10,402] exhibits clear
porphyritic crystals of quartz and orthoclase, both minerals in more
or less idiomorphic forms, embedded in, and occasionally corroded
by, a semi-crystalline ground mass. The ground mass contains some
calcite and iron oxides, probably arising from the decomposition of
a hornblendic or micaceous mineral.
[Illustration: Fig. 13.—Microperthitic structure in felspar of
quartz-felsite, Gebel Hadarba [12,147], as seen between crossed
nicols, × 40.]
The rocks of Gebel Hadarba [12,146-12,149] are essentially similar
to those of Gebel Igli el Iswid, but in some cases they show bright
red veining; where they have been exposed to the polishing agency
of the sand blast, these veined varieties look as though they had
been streaked with melted sealing-wax. In some of the slides the
felspars show a well marked microperthitic structure, while in others
they are so decomposed that they are barely distinguishable from the
ground mass. The ground mass sometimes contains granules and strings
of iron-oxide, possibly referable to alteration of a hornblendic
constituent, but the rock is too much altered for one to be sure.
[Illustration: Fig. 14.—Crushed oligoclase crystal in
quartz-felsite, Wadi Huluz [10,404], as seen between crossed nicols,
× 40.]
An altered and crushed quartz-felsite [10,404] which occurs in
the Wadi Huluz, near where the Wadi el Abiad joins it about eight
kilometres to the north-west of Gebel Hamata, somewhat resembles the
rock of Gebel Hadarba in appearance. It is a jaspery looking rock
of dark colour with red and greenish patches, in which with a lens
one can see scattered grains of glassy quartz. The slide cut from
the rock shows clear porphyritic crystals of quartz, orthoclase and
oligoclase in a fine grained ground mass. The porphyritic crystals
are mostly in rounded forms, but some of the felspars show a tendency
to idiomorphism. Many of the crystals are smashed, and some show
undulose extinction. The ground mass consists of quartz, felspar,
and some glassy matter, with abundant epidote in nests and strings,
and a small amount of green hornblende in straggling forms.
The east-and-west dykes which traverse the syenite of Gebel Zergat
Naam, and form the actual summit of that mountain, consist of a
very hard compact flesh-coloured rock which weathers brown on the
surface. The microscopic section [11,525] shows the rock to be
a highly indurated felsite. The original felspar crystals can be
made out by their shapes, but between crossed nicols they are seen
to consist of a very fine-grained mosaic polarising in low greys,
probably the result of alteration by siliceous solutions. These
altered felspars are scattered with some quartz in a cryptocrystalline
ground mass.
No volcanic rocks of acid type have been with certainty identified
in South-Eastern Egypt. It is, however, possible that some of the
rocks above described are in reality of volcanic origin, though the
manner of their occurrence is more suggestive of intruded masses
and sheets. It is also quite likely that some of the hornfels found
associated with the schists, as for instance at Gebel Um Semiuki, near
Abu Hamamid, are altered forms of glassy acid lavas; but their vast
age and the intense metamorphism to which they and the surrounding
rocks have been subjected render it impossible to be certain of the
manner of their origin.
INTERMEDIATE IGNEOUS ROCKS.
(_a_) =SUB-ACID ROCKS.=
=Syenite and Syenite-porphyry.=
Though hornblendic varieties of granite are fairly common, true
syenite (_i.e._, orthoclase-hornblende rocks with little or no quartz)
is amongst the rarest of rocks in South-Eastern Egypt. It occurs
near Gebel Nazla (between Bir Um Gubur and Bir Masur), in the two
remarkable conical hills called El Nahud, which rise from the plain
near the head of Wadi Natash, and at Gebel Zergat Naam. In all these
three localities the syenite appears to form intrusive bosses rising
through the surrounding rocks.
The specimens from near Gebel Nazla [10,625] and from El Nahud
[10,857] are very fine-grained reddish-brown rocks, which can be
seen with a lens to be largely made up of red orthoclase crystals
with dark specks of hornblende.
[Illustration: Fig. 15.—Syenite of Gebel Zergat Naam [11,515],
× 10. _o_, orthoclase felspar, showing striations parallel to the
basal planes; _h_, hornblende deep green in colour; _g_, interstitial
quartz.]
[Illustration: Fig. 16.—Syenite-porphyry, Gebel Zergat Naam
[11,512], as seen between crossed nicols, × 10. _f_, porphyritic
felspar (orthoclase); _h_, hornblende; _g_, microgranitic ground
mass containing felspar, hornblende, and some quartz.]
The syenite of Gebel Zergat Naam [11,515] rises as a great boss
from among the surrounding dark schistose rocks. It is typically
a pinkish-brown rock of rather fine grain (_see_ Plate XXIII), in
which can be seen shining crystals, three to four millimetres long,
of pink orthoclase, and specks of dark hornblende, with here and
there a little glassy-looking quartz. The sp. gr. is 2·62. Under the
microscope the rock is found to be mainly composed of orthoclase,
with a much smaller amount of hornblende and a little interstitial
quartz. The felspar is fairly clear, in forms approximating to
idiomorphic, and showing the characteristic simple twinning of
orthoclase. The crystals are slightly clouded in streaks parallel to
the basal planes, so that even in ordinary light a faint herring-bone
structure is visible, the streaks on either side of the trace of
the plane of composition being inclined to each other at a large
angle. Between crossed nicols this herring-bone structure is very
strongly marked, and is evidently due to a perthitic intergrowth
(of albite?). The intergrown lamellæ are slightly irregular; though
following generally the direction of the basal cleavage planes they
are not perfectly straight, nor always continuous across the half
of the crystal. The lamellæ extinguish and attain their maximum of
brightness simultaneously with the respective halves of the crystal in
which they occur, so that they become invisible in certain positions
of the nicols; but as the nicols are turned they appear as well marked
dark bands, clearly visible even under low powers. The hornblende is
of exceptionally dark green colour, in irregular straggling masses,
often considerably decomposed and clouded with iron oxide. Accessory
minerals, other than the clear interstitial quartz, appear to be
almost entirely absent in the slide examined.
=PLATE XXIII.=
[Illustration: Ball.—Geography & Geology of South-Eastern Egypt.
=INTERMEDIATE IGNEOUS ROCKS.=
=PINK SYENITE.= Gebel Zergat Naam.
=TRACHYTE.= Gebel Kahfa.
=DIORITE.= Gebel Allawi.
=DIORITE WITH PRISMATIC HORNBLENDE.= Wadi Muqur.
=BANDED ANDESITE.= Gebel Sufra.
=VEINED KERSANTITE.= Gebel Fereyid.
NATURAL SIZE.]
In places, the rock of Gebel Zergat Naam takes on a finer grain
and a greyer aspect in the mass. A slide cut from this variety
[11,512] shows essentially the same composition, but the felspars
are here porphyritic in a crystalline ground mass of felspar
and hornblende. The rock thus passes into syenite-porphyry. The
porphyritic felspar crystals show the same lamellar structure as
those in the more coarsely crystalline rock.
=Trachyte.=
[Illustration: Fig. 17.—Trachyte, from a dyke at Gebel Kahfa
[11,537 A] × 10. A clear crystal of orthoclase felspar is seen in
the centre of the field, surrounded by a finely crystalline ground
mass of hornblende and felspar.]
Trachyte, the volcanic representative of syenite, occurs in dykes
[11,537 A] seaming the granite of Gebel Kahfa. It is a light grey
rock, of very fine grain, breaking with a rough surface, containing
pores and small stumpy white pearly-looking porphyritic crystals
of orthoclase (_see_ Plate XXIII). The sp. gr. is 2·56. The
microscope shows the ground mass surrounding the porphyritic
idiomorphic orthoclase crystals to be a holocrystalline mixture
of hornblende and felspar. The felspars of the ground mass are
usually in more elongated forms than the porphyritic crystals, and
appear to be partly plagioclase. The hornblende, in small and very
irregular crystals of dark olive-green colour, often clouded and
dirty looking, is scattered plentifully among the feslpars of the
ground mass. Accessory primary minerals appear to be entirely absent.
A rock which occurs in a hill at the head of Wadi Amba-ut [10,375]
appears to be essentially similar to the above, but the porphyritic
orthoclases are more numerous and the ground mass contains small
quantities of augite and magnetite. This rock is in a highly altered
condition, the felspars being full of kaolin and epidote, while the
hornblende, which is here of a paler colour than in the trachyte of
Gebel Kahfa, is highly chloritised.
(_b_) =SUB-BASIC ROCKS.=
=Diorite.=
Though not forming such conspicuous features as the granites, rocks of
dioritic composition are very widely distributed over the country,
and are specially abundant in the districts to the south of Ras
Benas. They are almost always sharply marked-off from the granites,
being generally closely connected with the more basic igneous rocks
and schists. The coarser-grained varieties usually form parts of
irregular intrusive masses, shading off gradually into the more basic
forms of diabase, gabbro, and hornblende rock; the finer-grained types
occur as dykes and irregular bands traversing other igneous rocks
and schists, and are themselves frequently so crushed as to resemble
schists. Owing to their intimate association with other dark rocks,
it is no easy matter to trace the limits of the diorites in the
field. The same difficulty is found when they are microscopically
examined, for one finds in their mineralogical composition every
gradation from true diorites, through the intermediate stage of
augite-diorite to diabase and gabbro, while many of the harder dark
schists and hornblende gneisses turn out to be merely highly crushed
diorites, so that classification must be more or less arbitrary.
Diorite typically forms low hill country of dark aspect. The rock
weathers as a rule far more easily than granite, and in some cases
the debris of rounded grains set free by disintegration cover the
surface and render the climbing of the hills somewhat dangerous,
the effect being like one would imagine to result from walking over
slopes covered with hard peas.
[Illustration: Fig. 18.—Diorite of Gebel Allawi [10,313], ×
10. _pl_, plagioclase felspar, clouded by decomposition products;
_h_, hornblende, olive-brown in colour; _ha_, hornblende altering
to pale-green chlorite; _m_, magnetite.]
Diorite in the narrowest sense of the term (plagioclase-hornblende
rock) is not by any means abundant. Curiously enough, it is generally
found in the neighbourhood of old gold mines, as for instance in the
Kurdeman and Allawi districts, and it was employed by the ancient
miners for their crushing pans. The rock from Gebel Allawi [10,313]
is a medium-grained one composed of black and milk-white minerals
in about equal proportion (_see_ Plate XXIII). Its sp. gr. is
2·95. Under the microscope the milk-white material is seen to be
plagioclastic felspar, generally much decomposed, while the dark
grains are of hornblende, pale green to olive-brown in thin section,
with somewhat feeble pleochroism. Like the felspar, the hornblende
is considerably altered; in places it has lost nearly all its colour
and is converted into pale green chlorite. The accessory minerals
are iron-oxides and a little sphene. Rocks of somewhat finer grain
[10,358] occur in the Rod el Ligaia. In a slide from the last-named
locality, granules of ilmenite are surrounded by sphene, suggesting
the formation of sphene by the alteration of ilmenite. A variety of
diorite [10,403] occurs in the Wadi Huluz in which the hornblende
is nearly colourless, showing only a trace of green colour in thin
section, and is accompanied by a small amount of augite.
[Illustration: Fig. 19.—Diorite, Wadi Baaneit [12,151], × 10. _h_,
hornblende; _pl_, plagioclase; _b_, accessory biotite; _q_, accessory
quartz.]
A form of diorite which occurs in and about the Wadi Baaneit [12,151]
is very similar to the rock just described, but differs from it
in the more irregular manner in which the two principal mineral
constituents are distributed. The hornblende is in patches varying
from mere specks to eight millimetres in diameter; the felspars have
a sugary appearance in the hand specimen. The sp. gr. is 2·81.
A more highly specialised type of diorite [12,103] occurs in the
Wadi Muqur. This is a very beautiful heavy rock (sp. gr. 2·87),
with shining prisms of hornblende, often three centimetres or more
in length, running through a mass of white felspars (_see_ Plate
XXIII). Microscopic examination reveals the presence of some quartz
mixed with the plagioclastic felspars.
Where the alteration of diorite has been very intense, as in the
country rock [12,124] of the old Romit mine, the hand specimen
differs from that of the unaltered rock in that not only are the white
constituents of duller aspect, but the dark mineral, instead of being
black and shining, has a dull greenish-grey appearance. Under the
microscope one sees no trace of the original felspar, its place being
taken by calcite and a confused aggregate of small plates of kaolin
and sericite, while the hornblende is all replaced by chlorite, with
little strings of limonite. Granules of quartz, often of relatively
large size, are scattered through the mass; some of these are clouded
by minute enclosures, and evidently represent the accessory quartz
of the original rock, while others are clearer and are probably of
secondary formation.
Fine-grained varieties of diorite are found much more abundantly than
the normal plutonic type, occurring as irregular masses mixed with
schists and as dykes in schists and other rocks. These fine-grained
diorites are essentially similar to the coarser-grained rocks,
but are generally even more altered. The fine-grained diorite
[11,517 A], which forms the top of Gebel Um Tenedba, for instance,
consists of a mixture of clouded and altered plagioclase and augite
altering to chlorite, with separated iron oxide along the cleavage
planes of the hornblende. Another specimen of fine-grained diorite,
from a dyke in Wadi Kreiga [12,154], is even more highly altered,
the hornblende being almost entirely chloritised, with formation of
abundant little granules of epidote.
The main rock of Gebel Beida [12,160] may also be classed as an
altered fine-grained diorite. It is a dark fine-grained greenish-grey
rock with white and greenish-yellow spots, usually about two
millimetres diameter, scattered through it, and abundant strings of a
greenish yellow mineral. The sp. gr. is 2·96. Under the microscope
it is seen to be of similar nature to the rocks last described,
the hornblende being largely chloritised. There is a considerable
amount of accessory augite, and this, though clouded, has resisted
alteration better than the hornblende. The whitish spots seen in
the hand specimen are made up of a fine mosaic of quartz grains,
with tiny flakes of a micaceous mineral (sericite?) probably all
of secondary origin, while the greenish-yellow strings are other
alteration products in the shape of epidote and calcite.
=Augite-diorite.=
Under the head of augite-diorite are classed holocrystalline
rocks containing, in addition to the plagioclase and hornblende of
ordinary diorites, notable quantities of augite. The augite-diorites
thus form a link between the diorites proper and the diabases or
plagioclase-augite rocks.
The presence of augite along with the hornblende is difficult to
ascertain in the field or in hand specimens, and can as a rule only
be detected by the microscopic examination of thin sections. But
augite diorites are generally of somewhat darker aspect than normal
diorites in the mass, owing to a less abundance of felspar, and are
generally tougher under the hammer.
[Illustration: Fig. 20.—Augite-diorite, Wadi Um Hargal [11,535],
× 47. _h_, hornblende; _a_, augite, with celephytic border _c_, of
hornblende and iron oxide; _f_, felspar (labradorite); _ap_, apatite.]
An augite-diorite [11,535] which occurs on the pass at the head
of Wadi Um Hargal, near Gebel Kahfa, is a heavy (sp. gr. 2·87)
grey rock of medium grain, very fresh and hard, in which can be
seen lustrous black crystals mixed with a rather small quantity
of white felspars. In thin section, hornblende, the most abundant
constituent, is in fairly large allotriomorphic crystals, with well
marked cleavage and strong pleochroism (bluish-green to pale yellow),
containing abundance of irregular granules of iron oxides. The augite,
which is present to about one-third the amount of the hornblende,
is in crystals of similar size, and likewise showing well-marked
cleavage, easily distinguished by their pale brown colour, absence
of pleochroism, and higher extinction angles (about 40°); some of
the crystals show irregular cracking and clouding by decomposition
products, and are surrounded by celephytic zones of greenish matter of
rather lower double refraction containing flakes and strings of iron
oxide, probably representing a marginal alteration to hornblende. The
felspar, though considerably decomposed, still shows plagioclastic
twinning clearly, and appears from the extinction angles to be an
acid type of labradorite. The rock contains considerable amount of
magnetite scattered through it, often in fairly large irregular
grains, also a few small grains of apatite, and one or two small
granules of quartz.
[Illustration: Fig. 21.—Augite-diorite, Gebel el Anbat [10,411],
× 40. _pl_, plagioclase felspar; _a_, augite; _h_, hornblende,
arising from alteration of augite.]
The rock [10,411] which forms the dark hills called Gebel el Anbat,
near the head of Wadi Kharit,[131] is likewise an augite-diorite. In
the field it is seen weathered into rounded masses often resembling
boulders, of great hardness, and covered with a blackish-brown
skin. The sp. gr. is 2·97. Microscopic examination shows the rock,
which is very fresh, to be essentially of the same type as that last
described, but the augite is more abundant and so intimately mixed
with the hornblende as to suggest even more strongly an alteration
of augite to hornblende (_see_ Fig. 21).
=Mica-diorite.=
[Illustration: Fig. 22.—Mica diorite, from a dyke at Gebel Abu
Hegilig [10,391], × 17. _f_, felspar (mainly plagioclase); _b_,
biotite altering with formation of limonite; _h_, hornblende; _ap_,
apatite; _m_, magnetite.]
Most of the diorites of South-Eastern Egypt contain little or no
biotite as an accessory constituent. An exception occurs, however, in
a great dyke [10,391] of very fine grained diorite of sp. gr. 2·87,
which traverses the granite of Gebel Abu Hegilig, and which contains
more biotite than hornblende. The dyke is so decomposed that it is
difficult to get a coherent hand specimen; but a slide cut from one
of the less altered portions shows the rock to be a very fine grained
holocrystalline one, made up of plagioclase, biotite, hornblende,
apatite and magnetite, with abundant alteration products such as
epidote, kaolin, and chlorite. All the minerals, except the apatite
and some of the iron oxides, are allotriomorphic. The felspars are
very much altered, but appear to be mainly plagioclase. The biotite is
in little brown ragged-looking plates, strongly pleochroic, frequently
altered with separation of flakes of limonite. The hornblende is
green, in small and very irregular-shaped crystals, which show very
little trace of cleavage and are frequently chloritised. The apatite
is in long hexagonal clear prisms. Iron oxides, sometimes showing
square or hexagonal outlines, and epidote in granules, are liberally
scattered through the rock. From the abundance of biotite and the
fine grain and manner of occurrence of this rock it was taken in
the field for a decomposed lamprophyre; but the entire absence of
idiomorphism in the ferro-magnesian minerals show that it should
rather be placed with the diorites.
=Diorite-porphyrite.=
Rocks which may be somewhat doubtfully classed as altered
diorite-porphyrites occur at Gebel Abu Hodeid as well as near the
ruins of Um Eleiga and at Gebel Um Heshenib.
[Illustration: Fig. 23.—Diorite-porphyrite, Gebel Abu Hodeid
[12,143], × 40. _f_, porphyritic felspar (plagioclase); _h_,
hornblende; _b_, biotite; _g_, ground mass, consisting chiefly of
plagioclase and hornblende.]
The triangulation point on Gebel Abu Hodeid not being an occupied
station, I have not visited the mountain, but the guide sent to
erect the beacon on the summit brought back a specimen [12,143]
of the rock. It is a very fine-grained dark grey rock with tiny
glistening specks. The sp. gr. is 2·88. The microscopic slide shows
it to consist of porphyritic plagioclase in a very fine-grained
holocrystalline ground mass composed principally of brown hornblende
and plagioclase, with a little biotite and a plentiful sprinkling
of tiny granules of iron oxides. The porphyritic plagioclases
are inclined to idiomorphic forms, forming crystals about half a
millimetre in length, and hence are not very conspicuous in the hand
specimen; they are considerably clouded by decomposition, but still
show repeated twinning very clearly. The hornblende, which forms the
main constituent of the ground mass, is of a pale to dark yellow-brown
colour, mostly in rounded granules in which cleavage is not very
strongly marked. The plagioclase of the ground mass is likewise in
tiny granules, mixed with the hornblende. Biotite is only sparingly
present in the slide; it is in tiny brown flakes. All the minerals
of the ground mass show more or less decomposition and clouding,
and contain a fairly plentiful sprinkling of minute grains of iron
oxides; flakes of this latter substance are specially evident in
the decomposing biotite.
The diorite-porphyrite of Um Eleiga [11,527 B] occurs associated
with fine grained gabbro round the old mines. It is a grey rock,
breaking with a rough surface, in which porphyritic lath-shaped
felspar crystals, up to three millimetres long, are somewhat
sparsely scattered in a fine-grained ground mass. The sp. gr. is
2·82. The microscopic slide reveals the ground mass to be finely
holocrystalline, composed of plagioclase and pale green to brown
hornblende, with some magnetite. The plagioclase of the ground mass
is partly in little laths, and the hornblende frequently shows a
tendency to prismatic and fibrous forms. The whole rock is in a
rather advanced state of alteration, all the crystals in the slide
being strongly clouded by kaolin and other decomposition products.
The summit rock of Gebel Um Heshenib [10,392] appears to be a highly
altered basic diorite-porphyrite forming a dyke in the surrounding
schists. It is a dark-grey heavy rock (sp. gr. 3·04), of basaltic
appearance, with white porphyritic patches, more or less rounded in
form, scattered through it. The microscopic slide shows the white
patches now to consist mainly of kaolinic matter, with which is
mixed a clear mineral (sericite?), of very low refractive index, but
showing rather high double-refraction colours; while the ground mass
is a very fine-grained mixture of rather fibrous pale green hornblende
with kaolinic matter. Hardly a trace of unaltered felspar remains, but
it seems natural to ascribe the kaolin both of the porphyritic areas
and of the ground mass to the decomposition of original felspars.
A dyke of fine-grained brown rock which occurs in the granite of
the lower part of Wadi Kreiga [12,102] likewise appears to be an
altered diorite-porphyrite. It is much less dense than the rock
last described, its sp. gr. being only 2·68. The microscopic slide
shows the main constituent to be plagioclase felspar in idiomorphic
forms, much altered to kaolin and calcite and stained red by iron
oxide. Between the felspars are irregular patches of chloritic
and serpentinous matter, with calcite and flakes of limonite, the
alteration products of a ferro-magnesian mineral which was probably
originally hornblende.
=Augite-porphyrite.=
[Illustration: Fig. 24.—Augite-porphyrite, Wadi Muelih [10,359],
× 40. _a_, augite; _pl_, plagioclase; _h_, hornblende, much clouded
with iron oxides. The rock contains large porphyritic plagioclase
and hornblende crystals not shown in the figure.]
A dyke of augite porphyrite [10,353] occurs in the Wadi Muelih
about half-way between Gebel Muelih and Erf el Fahid. It is a
fine-grained reddish-brown rock of sp. gr. 2·79, with porphyritic
white plagioclase crystals of considerable size (up to two
centimetres in length) and other smaller porphyritic crystals of a
dark schillerized-looking mineral. The ground mass, when examined
with a hand lens, is seen to be a very fine-grained mixture of red
and dark minerals, like a syenite in miniature. The microscopic slide
reveals the dark porphyritic crystals as green hornblende, while the
ground mass is a holocrystalline mixture of plagioclase and augite,
with a little green to brown hornblende and abundance of magnetite
granules. The felspars of the ground mass are mostly lath-shaped;
they are much altered, and stained red by iron oxide. The augite, of
a very pale purple colour, is abundant in the ground mass, sometimes
in prismatic forms, but more often in rounded grains; it is altered
in places to chlorite, becoming then green in colour. The extinction
angles measured in the less-altered crystals range to over 40°.
=Kersantite.=
[Illustration: Fig. 25.—Kersantite, from a dyke at Gebel Fereyid
[11,504], × 40. _f_, felspar (mainly oligoclase); _b_, biotite;
_a_, augite, with a border of hornblende (_h_); _ap_, apatite.]
Only one occurrence of a rock which can be with certainty classed
as a lamprophyre has been noted in South-Eastern Egypt. The single
occurrence referred to is that of a kersantite [11,504] which
forms a dyke cutting east-and-west through the granite of Gebel
Fereyid. In the hand specimen (_see_ Plate XXIII) it is a fine grained
dark-grey rock, marbled with veinlets of brownish-white granular
(felspathic?) material, and containing here and there porphyritic
dark-brown platey crystals up to three millimetres in diameter. The
sp. gr. is 2·81. Under the microscope, the rock presents a very fresh
appearance, and is seen to be composed mainly of felspars and brown
biotite, with a little accessory augite, green hornblende, apatite
and magnetite. The biotite, the most conspicuous constituent, is seen
partly in basal sections of perfectly idiomorphic forms, and partly
as long lath-shaped sections; it is strongly pleochroic, the colour
varying from pale yellow-brown to a very dark reddish-brown. The
felspar, which has undergone some alteration, forms a sort of matrix
round the biotite; here and there large crystals show a tendency to
idiomorphism, but the felspar is essentially allotriomorphic. The
felspar appears to be mainly oligoclase; but there are also some
crystals which show only simple twinning, and these are doubtless
orthoclase. The augite and hornblende are very sparingly present,
the former in nearly colourless to purplish crystals, the latter in
tiny forms of a deep emerald or bluish-green colour, with very high
double refraction. Magnetite is liberally scattered in small grains
through the rock, seldom included in the biotite. Apatite occurs in
very fine long needles among the felspars.
=Andesites.=
Andesites, the volcanic representatives of the diorites, are much
more scarce in the south portion of the Eastern Desert than they
are further north. In the district here treated of, only a single
deposit, that of Gebel Sufra, has been noted as belonging certainly
to the class of andesitic lavas. Some other volcanic rocks consisting
chiefly of hornblende and plagioclase have been met with, as for
instance at the hill of Ti Keferiai and in the Wadi Huluz; but these
are of so basic a nature that they are more properly classed as
hornblende-basalts. It is also practically certain that some of the
rocks which must be classed as schists on account of their structure
are metamorphosed andesites; among the schists of the Wadi Muelih, for
example, are rocks which in thin section present a ground mass still
distinctly andesitic in character, but the hornblendic constituent,
instead of forming well-defined porphyritic crystals as it doubtless
originally did, is dragged out into fibrous forms, and the same
action can be traced in the hornblendes of the ground mass.
The andesite of Gebel Sufra [10,597] occurs as a columnar deposit
overlying syenites and diorites at the top of the mountain, which
rises to 690 metres above sea-level in latitude 24° 39′. The rock,
which is a fine-grained greenish-grey one weathering to a brown colour
on exposed surfaces, often shows a banded structure (_see_ Plate
XXIII). The sp. gr. is 2·67. The microscopic section shows the rock
to be highly altered, but sufficient traces of its original nature can
be made out to leave little doubt of its being an andesitic lava. The
slides show porphyritic felspars in a cryptocrystalline ground
mass composed of felspar with a little hornblende and biotite. The
porphyritic felspars are too much kaolinised for twinning to be
made out, but a little calcite is visible in their decomposition
products, and the crystals are in rather elongated forms which suggest
plagioclase rather than orthoclase. The minerals of the ground mass
are likewise much decomposed, but tiny grains of green hornblende and
wisps of brown biotite, both altering to chlorite, can be seen. There
is an almost complete absence of primary iron oxides, but a single
large porphyritic crystal in the slide shows separated hæmatite in
flakes and in strings down its cleavage planes. The nature of this
single crystal is not very clear, and it is doubtful if any of its
original substance remains; its form and cleavage are suggestive of
augite, but the clear spaces unoccupied by the iron oxide have the
appearance of quartz or clear felspar under crossed nicols.
[Illustration: Fig. 26.—View near the top of Gebel Sufra, showing
the columnar structure of the andesite.]
[Illustration: Fig. 27.—Andesite of Gebel Sufra [10,597], as seen
between crossed nicols, × 40. Porphyritic felspar crystals in a
cryptocrystalline ground mass.]
BASIC IGNEOUS ROCKS.
=Gabbro.=
Gabbros (or plutonic plagioclase-pyroxene rocks with or without
olivine) are widely distributed in South-Eastern Egypt, entering
largely into the composition of some conspicuous mountains such as
Gebels Atut, Madaret Um Gamil, Um Gunud, Um Bisilla, Dahanib, Gerf,
and Hadal Aweib Meisah, and also occurring in smaller patches at
various other points.
Though they are all dark-coloured, tough and heavy rocks (specific
gravity from 2·8 to 3·2), the gabbros vary very much in appearance
at different places owing to variations in size of grain and
in mineral composition. Thus we have every gradation from the
coarse-grained gabbros such as those of Um Bisilla and Gerf, where
the individual crystals measure sometimes two or three centimetres in
length, through the medium grained rocks of Atut, Dahanib and Hadal
Aweib Meisah, to the granulitic gabbro of Kolmanab hill, of which
the grain is so fine that the rock looks almost like a basalt. In
mineral composition, the gabbros show likewise great variety. Some,
like the rocks of Um Bisilla, are relatively rich in felspar, and
are lighter both in colour and in weight than others in which the
pyroxenes predominate; in some cases the proportion of felspar almost
vanishes and the rock passes into a pyroxenite. Some of the gabbros,
such as those of Atut, contain olivine, while others, such as the
rocks of Gebel Dahanib, do not. The nature of the pyroxene varies,
being sometimes almost entirely diallage, while in others it is mainly
ordinary augite, and in others, again, rhombic pyroxenes such as
bronzite and hypersthene occur. A further variation is the presence of
hornblende in some gabbros, either as an accessory primary constituent
or as an alteration product of a pyroxene. In the uppermost rock of
Gebel Um Bisilla we have an example of troctolite, a form of gabbro
in which there is no pyroxene but only felspar and olivine.
In the field, mountains and hills formed of gabbro are typically of
dark aspect, though frequently less dark than a freshly broken surface
of the rock, owing to a film of iron-oxide which forms on weathered
faces. This film is most strongly marked in the olivine-bearing
varieties of the rock; it is very thin, good sound rock being usually
found at a depth of a millimetre or so below the exposed surfaces. In
form, hills of gabbro are usually in the form of flattish cones
and ridges, whose surfaces and summits are covered with a debris
of rusty-looking weathered blocks of the rock. This blocky type of
summit is well seen at Gebel Atut (_see_ the view on Plate X, p. 172).
Though sometimes sharply marked-off from the adjacent rocks, gabbros,
when traced laterally in the field, are most frequently found to pass
gradually into more basic forms such as pyroxenites, amphibolites,
and serpentines. It is not always easy in the field to distinguish
between augite or diallage and hornblende, and one or two rocks
which were taken for gabbros turn out on microscopic study to be
really basic diorites or hornblende-rocks; while a rock at Um Eleiga,
which strongly resembles a rather fine-grained diorite in appearance,
turns out to be a gabbro. The limit between gabbros and peridotites
is exceptionally difficult to map, the proportions of olivine, augite,
bronzite, and felspar changing very frequently in the same rock mass,
as for instance at Gebel Gerf.
Almost all the gabbros contain a considerable amount of magnetite as
an accessory constituent, and in some cases, as at Gebel Hadal Aweib
Meisah, magnetite is present in such quantity as to render the rock
strongly magnetic. Compass readings in the neighbourhood of large
masses of gabbro are almost always subject to more or less error
from this cause. In the case of a gabbro discovered by Dr. Hume to
the west of Gebel Ranga, near the coast about latitude 24° 24′,
concentration of the ferruginous matter has gone on to such a degree
as to give rise to deposits of hæmatite containing 39 per cent
of iron.[132]
Perhaps the most striking feature evident in the microscopic slides
cut from the gabbros is the remarkable freshness of the felspars
in most of the specimens, which, taken in conjunction with the
basic nature of the rocks, inclines one to consider the basic
rocks as probably on the whole amongst the youngest of the plutonic
masses. Another characteristic feature is “celephytic” structure,
in which a shell of green hornblende is found to surround the iron
oxides and pyroxenes when they are embedded in, or in contact with,
the surrounding felspar.
[Illustration: Fig. 28.—Gabbro, Gebel Dahanib [11,509], × 17. _f_,
felspar (labradorite); _a_, augite; _d_, diallage; _b_, bronzite;
_h_, hornblende, probably produced by alteration of augite.]
A typical olivine-free gabbro [11,509] forms the main rock of
Gebel Dahanib. A specimen taken from the summit, where the rock is
rather finer in grain than that of the rest of the mountain, is very
hard and heavy (sp. gr. 3·15), and is formed of a mixture of dark
dull-looking mineral with shining white to colourless felspars. Under
the microscope it is seen to be a holocrystalline aggregate of fairly
fresh labradorite and pyroxene, both in allotriomorphic forms, in
about equal proportions. About half the pyroxene is in the form of
diallage, the remainder being mostly ordinary augite; it is almost
colourless in thin section, but some of the crystals show a slight
pleochroism, colourless to pale pinkish-brown. The augite crystals are
much cracked, and frequently show signs of alteration with formation
of calcite, epidote and serpentinous matter. There are a few small
irregular areas of very pale green hornblende mixed with the augite,
of which they may possibly be products of alteration. One or two
elongated crystals in the slide, barely distinguishable from the
augite under ordinary light, show a fibrous structure and straight
extinction with low double-refraction colours; these are probably
bronzite. There are only a few very tiny grains of iron oxide,
and olivine appears to be absent from the slide examined.
[Illustration: Fig. 29.—Gabbro, Um Eleiga [11,527 A], × 17. _pl_,
plagioclase; _pc_, clouded plagioclase; _a_, augite; _m_, magnetite;
_s_, serpentinous matter probably from alteration of augite and
hornblende.]
A fine grained gabbro free from olivine occurs associated
with diorite round the old mines of Um Eleiga [11,527 A]. It
is a speckled black-and-white rock which would at first sight
be taken for a fine-grained diorite rather than a gabbro. Its
sp. gr. is 2·93. On microscopic examination the rock is found
to be a holocrystalline aggregate of plagioclase, augite, altered
hornblende, and magnetite, with granitic structure. The plagioclase
(labradorite) is considerably altered and clouded by kaolinic
matter, especially near the centres of the crystals, but still
shows its characteristic twinning clearly. The augite, which is
sometimes in the form of diallage, is fairly abundant, mostly in
irregular grains, though occasionally inclining to prismatic forms;
it is nearly colourless, but much cracked and slightly clouded. A
clouded pale green to brown mineral, which sends off long tongues
into cracks in the surrounding felspars, is also fairly abundant. This
mineral polarises in yellows and greys as a confused serpentine-like
aggregate of minute fibres, but contains clear and nearly colourless
areas representing the original mineral from which it is derived;
these clear areas, in which prismatic cleavage is usually well marked,
are sometimes augite, but in many cases they polarise in lower colours
(greys and yellows) than the augite, with low extinction angles, and
are probably hornblende. Magnetite is very abundant in quite large
irregular grains, often surrounded by a thin shell of hornblende or
of the clouded alteration product just mentioned. There are a few
small six-sided prisms of apatite, mostly included in the felspars.
[Illustration: Fig. 30.—Hypersthene-gabbro, Hadal Aweib Meisah
[12,126], × 4. _f_, felspar (labradorite); _a_, augite; _hy_,
hypersthene (the augite and hypersthene have the same appearance in
ordinary light); _m_, magnetite; _hb_, hornblende, forming celyphitic
borders round the augite and magnetite.]
Another variety of fine-grained gabbro, likewise free from olivine,
but containing hypersthene and some hornblende [12,126], forms
the upper portion of Hadal Aweib Meisah, and a very similar rock
[11,521] occurs in the hills five kilometres south-south-west of
Marwot Elemikan. The rock is very hard, of a grey colour on fracture,
weathering to blocks which have a rusty-brown skin. Its sp. gr. is
2·98. It is highly magnetic, and causes great disturbance of
the compass needle in its neighbourhood. The hand specimen shows
a mixture of shining white felspars with duller black minerals
(_see_ Plate XXIV). On microscopic study, the rock is found to be
a holocrystalline aggregate of plagioclase, augite, hypersthene,
hornblende and magnetite. The plagioclase, which forms about
two-thirds of the rock, is a very clear and fresh labradorite of
a rather acid type. The augite is usually in more or less rounded
grains, often aggregated into irregular strings and mixed with
hypersthene and magnetite. Only in a few cases does the augite show
diallagic lamellation. It is nearly colourless, with a slight greenish
or pinkish-brown tinge and faint pleochroism. The prismatic cleavages
are usually distinct, and in addition the crystals are irregularly
cracked. Twinning is fairly frequent, as also are inclusions of
magnetite in the augite. The hypersthene occurs in grains similar
to those of the augite, with which it is mixed, and from which at
first sight it is not easily discriminated; but it can be picked
out by its more marked pleochroism, straight extinction, and lower
double refraction. Magnetite is abundant in large irregular grains,
and in smaller granules included in the augite. Hornblende occurs
in subordinate amount to the other minerals, and is principally
seen as a celyphitic zone round the magnetite and augite crystals,
especially between these crystals and the felspars. It is usually
fairly clear, strongly pleochroic (deep greenish-brown to very pale
yellowish-brown), and where surrounding two or three grains of other
minerals the whole zone extinguishes at once, showing it to be a
single crystal.
=PLATE XXIV.=
[Illustration: Ball.—Geography & Geology of South-Eastern Egypt.
=BASIC AND ULTRA-BASIC IGNEOUS ROCKS.=
=OLIVINE-GABBRO.= Gebel Um Bisella.
=FINE-GRAINED GABBRO.= Hadal Aweib Meisah.
=TROCTOLITE.= Gebel Um Bisella.
=DIABASE.= Rod el Nagi.
=OLIVINE-BASALT.= Einiwai Hill.
=SERPENTINE.= Gebel Korabkansi.
NATURAL SIZE.]
[Illustration: Fig. 31.—Olivine-gabbro, Gebel Um Bisilla [11,514],
× 10. _pl_, plagioclase felspar (labradorite); _d_, altered diallage;
_o_, olivine, altered in places to serpentine (_s_), with separation
of granules of iron oxide.]
The main portion of Gebel Um Bisilla is formed of a gabbro
[11,514] containing a relatively small proportion of pyroxene and
a considerable amount of olivine. In the mass, it is a hard tough
rock, consisting of a mixture of white to greenish felspars, showing
plagioclastic twinning with the lens, with dull dark minerals, some
of a greenish colour and others of a rusty-brown appearance (_see_
Plate XXIV). The sp. gr. of the rock is 2·8. The labradorite, which
forms about two-thirds of the whole, is very fresh, but is here
and there decomposed with formation of calcite along cracks. The
pyroxenic constituent is now mostly represented by dusty looking
very pale greenish-brown straggling crystals interstitial to the
felspars; it appears to have been originally diallage, but is in an
advanced stage of alteration, polarising as a confused fibrous mass
of hornblende and chlorite, with irregular banding in a direction
inclined at about 30° to the general direction of the fibres. The
olivine is in large rounded grains, nearly colourless where unaltered,
showing the usual irregular cracks; some of the grains are altered to
yellowish-green serpentine, with separation of granules of iron oxide.
[Illustration: Fig. 32.—Olivine-gabbro, Gebel Atut [10,365],
× 17. _o_, olivine; _a_, augite; _h_, hornblende; _f_, felspar
(labradorite).]
Of the fine-grained olivine-gabbros, one of the principal types is
the rock of Gebel Atut and Madaret Um Gamil [10,365]. It is a dark
heavy rock, weathering into angular blocks with a thin rusty skin,
of great hardness and ringing under the hammer. On a fresh fracture,
it is seen to be made up of white glassy felspars and dark brownish
minerals, some of which have a platey structure with cleavage surfaces
which flash as the specimen is turned about in the sunlight. The
sp. gr. is 3·01. Microscopic examination shows the rock to be
a holocrystalline aggregate of plagioclase (labradorite), augite,
hornblende and olivine, with a very little magnetite. The labradorite,
which forms about half the rock, is very clear and fresh, in large
crystals which frequently show a tendency to idiomorphism. Smaller
crystals of labradorite are frequently included in the augite and
hornblende. Augite, the next most abundant constituent after the
felspar, is present in irregular almost colourless grains with
well marked cleavage and numerous irregular cracks, and sometimes
slightly clouded. The extinction angles measure up to 36°. The
hornblende is in some crystals of a rather pale greenish-brown
colour not showing very strong pleochroism, while in others it is
more strongly coloured, varying from a rather deep reddish-brown to
very pale yellowish-brown when turned over the nicol. The hornblende
and augite are frequently associated in such a manner as to suggest
that much of the hornblende in the rock originated from alteration
of augite. The olivine is fairly abundant in large rounded grains,
with the usual blackened irregular cracks; it is mostly fresh,
but here and there are patches converted into nearly colourless
serpentine with separation of numerous granules of iron oxide.
[Illustration: Fig. 33.—Olivine-gabbro, from a hill eleven
kilometres east of Gebel Selaia [10,412], × 17. _pl_, plagioclase
felspar (labradorite); _a_, augite; _hy_, hypersthene; _o_, olivine,
with irregular cracks marked by separated magnetite; _h_, hornblende,
enclosing the other minerals and forming a pseudocelephytic border
round the olivine and augite. The rock typically contains a somewhat
greater proportion of hornblende than appears in the figure.]
Another olivine-gabbro [10,412], which forms a hill rising from
the plain about eleven kilometres east of Gebel Selaia, resembles
that of Gebel Atut, but is rather coarser in grain and contains
less plagioclase, a larger proportion of hornblende, and probably a
little accessory hypersthene. It is a dense dark and tough rock of
sp. gr. 3·17, containing large black schillerized-looking crystals
sometimes measuring one centimetre across, and a liberal sprinkling
of white plagioclase with a few tiny grains of pyrite. Under the
microscope, very clear and fresh labradorite is seen to form less than
one-third of the rock; the crystals, which are mostly of irregular
outline, are frequently enclosed in the hornblende. The hornblende
occurs very abundantly as larger irregular green and brown crystals,
with well-marked prismatic cleavage; it often encloses crystals of
all the other minerals, forming a pseudo-celephytic border round the
enclosed augite and olivine. Augite is somewhat less abundant than
the hornblende, with which it is intergrown, in pale pinkish-brown
crystals, slightly pleochroic, with very distinct vertical
cleavage and irregular cracks. Twinning is not very frequent. The
extinction angles are usually under 30°. A few crystals which show
slightly stronger pleochroism (pinkish-brown to very pale green)
than the ordinary augite, and straight extinction, are probably
hypersthene. Olivine is present in about equal quantity with the
augite, in large irregular grains, much cracked, but otherwise fairly
fresh, polarising in brilliant colours; the cracks are blackened with
separated iron oxide, but there is very little serpentinisation. There
are a few small grains of pyrite and magnetite, but iron ores are
not nearly so conspicuous as in some of the other rocks of this class.
=Troctolite.=
[Illustration: Fig. 34.—Troctolite of Gebel Um Bisilla [11,522],
× 17. The crystals with the dark irregular cracks are olivine (_o_),
altering to serpentine (_s_); the resulting expansion has crushed the
surrounding clear plagioclase crystals (_pl_), forming large numbers
of curved cracks into which little tongues of serpentine project.]
If the gabbro of Gebel Um Bisilla is followed towards the summit, a
diminution in the pyroxenic content, with a corresponding increase in
the proportion of olivine, is noted, and at the top of the mountain
we have a troctolite, or rock composed essentially of plagioclase
and olivine [11,522]. It is a heavy speckled black-and-white rock,
made up of colourless to milky and greyish-black grains about three
millimetres diameter (_see_ Plate XXIV). Its sp. gr. is 2·84. The
rock looks like a diorite in the hand specimen; it weathers to
rusty looking blocks of remarkable hardness. Under the microscope
the mineral which looks greyish-black in the hand specimen is found
to be olivine, colourless where unaltered in thin section; but the
usual alteration to serpentine has gone on along irregular cracks,
and the separated granules or iron oxide give the black colour to the
mass. The felspar, which forms considerably more than half the rock,
is a very fresh, though occasionally much cracked, labradorite. Both
the constituent minerals are present in allotriomorphic grains.
=Pyroxene-granulite.=
[Illustration: Fig. 35.—Pyroxene-granulite, Kolmanab Hill
[12,132], × 40. _a_, augite; _h_, hornblende; _pl_, plagioclase;
_m_, magnetite.]
The rock [12,132] forming the hill called Kolmanab, which rises from
the coast-plain in latitude 22° 32′, resembles the fine-grained
olivine free gabbros very closely in composition, but on account of
its marked granulitic structure, is termed a pyroxene-granulite. The
rounded form of the grains has probably been conditioned by movement
of the magma during consolidation, but the rock contains no garnet
or other typically metamorphic mineral, and there appears to be
no reason for regarding this particular granulite as other than
an igneous rock. It will have been noted that the augite grains
in some of the fine grained gabbros show a marked tendency to
granulitic forms, and the rock of Kolmanab appears to be merely an
example of this tendency extending to the other constituents. The
field relations are such as to suggest an intrusive boss. The rock
is very hard and heavy, greyish-black and basaltic-looking; fresh
fractures show tiny glistening grains when turned about in the
hand. Its sp. gr. is 3·13. Microscopic examination shows it to be
essentially a granulitic mixture of augite and plagioclase with a
considerable amount of magnetite, and a little hornblende. All the
minerals are of remarkable freshness, in rounded grains about a tenth
of a millimetre in diameter. The augite, which forms about half the
rock, is of a very pale green colour, sometimes showing faint traces
of pleochroism with the same pinkish tints as hypersthene, from which,
however, it is easily distinguished by its high extinction angles. It
encloses abundant rounded colourless granules, which appear to be
felspar. The felspar is an acid labradorite, and forms a mosaic among
the augite grains; besides the twinned crystals, there are others
which show no trace of this feature, and some of these may possibly
be quartz. Hornblende occurs, not very abundantly, in larger crystals
than the other constituents, grains of which it frequently encloses;
it is of an olive-green colour. Magnetite is scattered through the
entire rock in rounded grains, and is specially frequent enclosed
in the hornblende.
=Diabases.=
Under the heading of diabase are included plagioclase-augite rocks,
with or without olivine, of a character intermediate between gabbro
and basalt. They differ from the gabbros in their finer grain,
in the general absence of diallagic structures in the augite, and
in the more or less porphyritic nature of their felspars, which
are often ophitically intergrown with the augite. They differ from
basalts, on the other hand, in being of coarser grain, and typically
containing no glassy matter. The diabases of South-Eastern Egypt
are more closely allied to the volcanic division of the basic rocks
(basalts) than to the plutonic (gabbros), and many of the rocks here
classed as diabases would be called dolerites by some English writers.
[Illustration: Fig. 36.—Diabase from under the Nubian sandstone,
Rod el Nagi [10,417], × 40. _pl_, plagioclase felspar, ophitically
intergrown with _a_, augite; _l_, limonite. The rock also contains
large porphyritic felspars, not shown in the figure.]
Perhaps the most interesting occurrence of diabase in this part of
Egypt is a thick bed underlying the Nubian sandstone and exposed
along the feet of its eastern scarps between latitudes 24° 30′
and 25°. Owing to the north-westerly trend of the scarp, it is
cut obliquely by the meridian of 34°, and consequently only the
southern portion of the deposit is shown on the geological map of
Plate XX. The bed is well seen on the west of the road leading from
Baramia to Dungash mines; this road follows the foot of the scarp
for a long distance. The thickness of the diabase sheet as seen on
this road is at least ten metres, and is very uniform for several
kilometres. The rock is crushed and decomposed to such a degree that
it is difficult to get a fair-sized specimen. Below the diabase,
at a few points along the road, there are exposures of an ancient
conglomerate of dark colour and extreme hardness. The relations
of the bed to the sandstone are not absolutely certain, but the
impression I got, when I passed the exposure on the two occasions of
my outward and return marches, was that the diabase was an extensive
outflow over the old conglomerate (thus indurating the latter), the
sandstone being subsequently laid down on the undenuded diabase. The
diabase is thus probably Cretaceous in age. A hand specimen [10,417]
from one of the least decomposed portions of the sheet, in the Rod
el Nagi, about fifteen kilometres west of Gebel Muelih, shows white
to glassy porphyritic felspar crystals, frequently in lath-shaped
forms measuring up to eight millimetres in length, in a fine-grained
grey ground mass (_see_ Plate XXIV). The rock contains many rusty
specks, and occasionally as one turns the specimen about in the
hand one can catch a rather dull flash from a crystal of some dark
mineral. The sp. gr. of the rock is 2·85. Under the microscope the
porphyritic felspars, which are very clear, are seen to be mostly
plagioclase, though some of the crystals show simple twinning and
may be orthoclase. The ground mass is holocrystalline, composed
of felspar, augite, and limonite. The felspars of the ground mass
are in the form of thin laths, with repeated twinning. The augite
is nearly colourless, with a very pale brownish or greenish tinge,
generally clouded by brown dusty matter and small irregular cracks. It
forms irregular grains which are cut up in all directions by the
ophitically intergrown felspars. The limonite is extremely abundant,
scattered through the ground mass in rather large irregular grains
which frequently show a tendency to square or hexagonal outlines;
it is mostly opaque, but in some parts it is translucent, with a
deep brown colour. The limonite is doubtless an alteration product
of other minerals, probably magnetite and biotite, of which, however,
no distinct traces now remain.
Besides forming the sheet under the Nubian sandstone, diabase occurs
fairly abundantly in schists at various points, where it appears
to form intrusions. A characteristic of these occurrences is its
weathering into rusty looking brown “cannon balls.” Altered forms
of diabase are associated with peridotites and other ultra basic rocks
in the serpentine mass of Gebel Gerf (_see_ p. 328). Diabase also
forms veins, frequently magnetic, penetrating granites and schists,
and at one point, near the foot of Gebel Awamtib, a dyke of diabase
is even found penetrating the Nubian sandstone.
It is probable that these diabases are of very different ages at
different points. While the occurrences associated with the sandstone
are certainly of Cretaceous age, it seems difficult to imagine that
those associated with the schists and serpentines are not vastly
older; for though they are obviously younger than the schists,
and possibly younger than the peridotites, they frequently show
metamorphism to a degree which it is difficult to reconcile with a
Cretaceous age, and which suggests that they antedated the folding
which formed the ancient mountain chain on the flanks of which the
Cretaceous strata were laid down.
[Illustration: Fig. 37.—Diabase, Gebel Abu Hamamid [10,400], ×
40. _a_, augite; _aa_, augite, altering with separation of iron oxide;
_pl_, plagioclase, often ophitically intergrown with the augite;
_s_, green serpentinous mineral; _m_, magnetite.]
As an example of a diabasic intrusion with “cannon ball”
weathering, we may take the rock [10,400], which occurs in schists
on the flanks of Gebel Abu Hamamid. When one of the rusty looking
“cannon balls” is broken, the interior is seen to be a dark
grey rock of very fine grain. The sp. gr. is 2·93. The microscopic
slide shows the rock to be holocrystalline, consisting mainly of
augite and plagioclase, ophitically intergrown, with some rather
large grains and strings of a nearly isotropic clear yellow-green
mineral, and scattered grains of iron oxides. The augite is of
a pale brown colour; some of the crystals are fairly clear, while
others show strong clouding and separation of iron oxide. The nature
of the yellow-green mineral is somewhat uncertain; it polarises
generally in very low colours, as an aggregate of fibres and tiny
plates, sometimes showing a spherulitic structure between crossed
nicols. Occasionally it includes granules of a highly refracting
colourless mineral, possibly olivine; but there is a remarkable
absence of the separated iron oxide which is usual with altering
olivine, and the granules exhibit only very fine irregular hairlike
cracks; if it is serpentine resulting from alteration of olivine,
the olivine must have been a variety poor in iron.
[Illustration: Fig. 38.—Olivine-diabase, from a dyke at the
junction of Wadis Huluz and Gemal [10,393], × 17. _o_, olivine;
_pl_, plagioclase.]
Turning now to the occurrence of diabase in dykes, a large dyke
in the gneiss at the junction of Wadis Huluz and Gemal [10,393]
consists of a very hard and heavy, strongly magnetic, greyish black
rock of rather fine grain, in which a dark-brown platey mineral is
mixed with grey and white matter. The sp. gr. is 2·95. Under the
microscope the constituents are seen to be plagioclase, olivine,
augite and magnetite, with small amounts of biotite and apatite. The
plagioclase appears to have formed in two generations, for while
the bulk of it is in small lath-shaped crystals (frequently with
radial grouping), there is a very large porphyritic zoned crystal
in the slide. The olivine is in large crystals, usually rounded,
but occasionally tending to hexagonal outline with the usual
strongly marked black irregular cracks. A little serpentinisation
has gone on at the edges and along cracks of a few of the crystals,
but, as a rule, the olivine is very fresh; it is never intergrown
with felspars. The augite is slightly pleochroic, of a purple to
brown tint, in irregular forms, partly in moderate sized crystals
and partly in tiny grains in the ground mass. The crystals are much
cracked. Ophitic structures are not conspicuous. Brown biotite is very
sparingly present in small flakes. Magnetite is liberally scattered
in small grains in the augite of the ground mass. Apatite occurs in
minute prisms included in the felspars.
[Illustration: Fig. 39.—Diabase, from a dyke in Wadi Kreiga
[12,110], × 17. _pl_, plagioclase felspar; _a_, augite; _h_,
hornblende; _l_, limonite strings.]
The diabase dykes which penetrate the granite in Wadi Kreiga [12,110]
differ from the rock last described in their freedom from olivine
and in showing marked ophitic structure. They are dense brown to
black rocks of very fine grain, with porphyritic felspar crystals
here and there. The sp. gr. is 2·98. Microscopic study shows them
to be holocrystalline rocks, composed of an ophitic mixture of
rod-shaped plagioclase with altering augite and hornblende. Both
the ferro-magnesian minerals are very much clouded, and contain
plentiful strings of iron oxide. The hornblende is dark green, often
forming celephytic shells round the augite, and is probably largely
an alteration from augite. There is very little of the nature of a
ground mass, the augite and hornblende practically filling all the
spaces between the felspars.
=Mica-diabase.=
[Illustration: Fig. 40.—Mica-diabase, Gebel Um Khariga [10,373]
× 17. _pl_, plagioclase felspar; _b_, biotite, with separated opaque
flakes of magnetite, often in geometric forms; _a_, clouded mineral,
probably altered augite, with which the felspars are ophitically
intergrown.]
The rock which forms the top of Gebel Um Khariga [10,373] appears to
be an altered mica-diabase. It is highly magnetic; the compass was
found to point 20° out of its normal position at the station on the
hill, while hand specimens broken off the rock showed strong polarity,
some parts attracting and other parts repelling the needle; a fragment
of the size of a pea deflected the compass needle several degrees
when placed near it. It is a dark brown rock, of sp. gr. 2·83, very
rotten, which in the mass looks like an altered dolerite. Microscopic
study of a slide reveals the presence of altered plagioclase,
in rather large lath-shaped crystals; biotite, largely altered to
opaque iron oxide, the flakes of which show marked geometric forms;
scattered grains of magnetite, and some secondary calcite. The
brown clouded mineral polarises as a confused fine-grained and
fibrous aggregate in low colours; it is probably altered augite,
with which the plagioclases were ophitically intergrown, but is in
too highly altered a state for certain identification. The strongly
magnetic character of the rock would appear to indicate that the
iron oxides produced by the alteration of the biotite are, like the
primary grains, in the form of magnetite.
=Basalt.=
Basalt, the volcanic representative of the gabbros and diabases,
is quite a scarce rock in South-Eastern Egypt, having been noted at
only four or five points. Fairly fresh olivine-basalts, probably
comparatively late intrusions, form the two conspicuous low hills
near the coast called Gimeida and Einiwai; more altered rocks of
basaltic type occur at the head of Wadi Um Deheisi (north of Gebel
Kahfa), and in the hills on either side of the Wadi Huluz some ten
kilometres north-west of Gebel Hamata; while an amygdaloidal rock
which forms a large part of the hill-mass of Ti Keferiai has been
classed as an altered hornblende-basalt.
[Illustration: Fig. 41.—Basalt, Gimeida Hill [12,156], ×
40. Porphyritic crystals of plagioclase (_pl_) and olivine (_o_) in
a hemicrystalline ground mass containing tiny crystals of plagioclase
and granules of augite (_a_) and magnetite (_m_).]
The basalt of Gimeida Hill [12,156], is a hard heavy block rock
of sp. gr. 2·88, of dull aspect, with glassy white to colourless
plagioclase crystals up to three millimetres diameter scattered
through it, and here and there a dark diallagic crystal and some
greenish glassy-looking grains of olivine. The microscopic slide
shows the rock to be remarkably fresh; the porphyritic plagioclase
and olivine crystals are seen to be embedded in a crystalline ground
mass containing little lath-shaped plagioclases, with granules of
pale brown augite, and abundant grains of magnetite.
[Illustration: Fig. 42.—Basalt, Einiwai Hill [12,144], × 17. _o_,
olivine; _a_, augite; _p_, picotite, with a border of opaque chromite;
_gr_, hemicrystalline ground mass.]
The basalt of Einiwai [12,144] differs from that of Gimeida in the
absence of porphyritic felspars. It occurs capping the red granite
which forms the lower part of Einiwai Hill and the surrounding
plain. It is a hard dull black rock with little glassy colourless
to pale green crystals plentifully scattered through it (_see_
Plate XXIV). The sp. gr. is 3·10. The microscopic slide shows
porphyritic crystals of olivine, augite, and picotite, in a very
fine-grained semi-glassy ground mass containing tiny laths of felspar
and grains of augite and magnetite. The porphyritic crystals all
show a remarkable absence of colour in the slide, which has been cut
exceptionally thin on account of the darkness of the ground mass;
this thinness of the slide doubtless accounts for the minerals all
showing relatively low polarisation colours. The porphyritic crystals
are mostly in six-sided and prismatic forms, but sometimes show
as rounded grains; cleavage is usually indistinct, but irregular
cracks are common, and some of the crystals are broken in two and
the halves separated. Most of the six-sided crystals show straight
extinction, and are probably a non-ferruginous olivine (forsterite);
they show very little alteration, there being a general absence
of serpentinisation or magnetite-separation along the cracks. The
prismatic porphyritic crystals are in forms resembling those of
augite, and some of the crystals show extinction sufficiently oblique
to justify their identification as augite; others, however, showing
straight extinction and very low polarisation colours, are probably
enstatite. The picotite is in rather large isotropic rounded grains,
of a pale green colour with a well marked opaque border of chromite.
A peculiar basaltic rock [10,408] occurs at the top of Wadi Um
Deheisi, at the pass into Wadi Um Retba, on the road which passes
from Bir Shadli to the north-east of Gebel Kahfa. It is a black rock
of sp. gr. 2·98, and of such fine grain that practically nothing
can be made out with a lens. It is remarkably magnetic, the compass
being deflected by 13° from its normal direction at a plane-table
station on the pass. The microscopic slide shows rounded and angular
clear areas in a cryptocrystalline ground mass of greenish colour,
full of specks of magnetite. The rounded clear areas are occupied
by a very pale brownish mineral, probably augite, forming nests of
crystals in different orientations, with fairly well-marked cleavages,
high extinction-angle and fairly high double refraction. The angular
clear areas are mostly colourless; they seem to consist chiefly of
altered felspar, but some of them are formed of a fine mosaic of
quartz granules. The ground mass is largely of chloritic nature,
with small fibres of hornblende and some decomposed felspar. Its
large content of rounded magnetite granules accounts for the magnetic
character of the rock.
The basalt of the Wadi Huluz [10,410] is a close grained
greenish-black rock containing white spots (amygdules) up to three
millimetres diameter. Its sp. gr. is 2·93. The microscope shows
the main bulk of the rock to be formed of lath-shaped plagioclase
crystals, around and between which is green matter, now mostly
chlorite. Here and there are small clear areas within the green
patches, which show bright polarisation colours, and are probably
augite, being the remains of the original mineral which has been
largely chloritised. There is a fair amount of magnetite in scattered
grains. The amygdules are partly filled with clear quartz, and partly
with zeolites.
The hill mass of Ti Keferiai is largely made up of a fine-grained
black rock [12,120], of sp. gr. 2·99, in which are greenish-white
and pink amygdules up to two millimetres diameter. It is frequently
much crushed, and in one place it has been broken into a coarse
breccia and cemented with rose quartz [12,123]. The microscopic
slide shows the main part of the rock to be a fine-grained mixture
of pale hornblende with altered plagioclase, while the amygdules
are filled with radiating zeolites. The amygdules seem to indicate
that the rock is a volcanic one, and it has been classed as a basalt
rather than as an andesite on account of its basic nature and high
specific gravity. Its texture is microgranitic rather than basaltic,
a circumstance perhaps in part due to the crushing it has undergone;
the rock is passing into a schist.
=Ultra-basic Igneous Rocks.=
The ultra-basic igneous rocks (_i.e._, rocks practically free from
felspar and composed entirely of ferro-magnesian silicates such as
pyroxenes, amphiboles, and olivines), though forming but a small part
of the earth’s crust in general, occur in very large proportion in
the igneous masses of South-Eastern Egypt, where they cover several
hundred square kilometres and form prominent mountain-masses such
as those of Gebels Dahanib, Korabkansi, and Gerf. They may be
classified into:—
(_a_) _Pyroxenites_ (rocks composed essentially of pyroxenes);
(_b_) _Amphibolites_ (rocks composed essentially of hornblende);
(_c_) _Peridotites_ (rocks composed essentially of olivine,
with or without pyroxenes and amphiboles);
All these ultra-basic rocks are easily altered to
(_d_) _Serpentines_, in which the original minerals may or may
not be traceable.
A characteristic of the ultra-basic rocks here, as in other parts
of the world, is their gradual transition into one another, showing
that the various forms have arisen from consolidation of parts of
one and the same magma owing to slight differences in composition
or in the physical conditions under which consolidation has taken
place. A further noteworthy circumstance is their gradual passage
into basic rocks; there is no hard-and-fast line to be drawn,
for instance, between basic diorites and amphibolites, nor between
basic gabbros and pyroxenites, nor between olivine gabbros, poor
in felspar and peridotites, these various classes being found to
pass by insensible gradations one into another as they are followed
up in the field. Moreover, being typically coarse-grained rocks,
and pyroxenes and amphiboles being often indistinguishable in the
hand specimen, great caution has to be exercised in naming a rock
mass from a few microscopic slides which of necessity each embrace
at most but a few square centimetres of section.
In the field, the appearance and cohesive strength of the ultra-basic
rocks varies primarily with the extent to which they have been
altered towards their final stage of serpentinisation. Where they
are least altered, they form black masses of hard heavy crystalline
rock of such toughness that they are only broken with difficulty
with a sledge hammer; while in the cases where serpentinisation has
proceeded to the greatest extent, they frequently form foxy red or
even pink-looking hills which might almost be taken for granite from a
distance, and they are so shattered that the rock comes off literally
in tons at a mere touch; in these cases, long search is necessary
to find a coherent piece large enough for a museum specimen. The
brown or pink colour just referred to is of course only superficial,
but in the untrodden and rainless wilderness surface films remain
unbroken and give characteristic colours to the scenery. Freshly
fractured surfaces are always dark green, dark brown, or black,
with more or less crystal structure visible according as the rock is
less or more altered; pyroxenites or amphibolites, when but little
altered, are a mass of lustrous platey or fibrous dark crystals,
while serpentines are typically of dull aspect. The specific gravity
is high, ranging from as much as 3·1 in the less altered forms down
to about 2·6 in those which are more completely serpentinised.
The process of serpentinisation is of course a chemical change,
consisting largely in the combination of water with ferro-magnesian
silicates free from alumina; but it is remarkable how frequently
this chemical change has been accompanied by a parallel physical
deformation. Serpentines are almost always shattered rocks, full of
slickensided surfaces; when we compare the low sp. gr. of serpentine
(2·6) with that of augite, hornblende, or olivine (about 3·2),
we naturally conclude that the shattering of the rock is in all
probability due to the expansion on hydration causing internal stress,
and the slickensiding is due to the rock yielding along certain
surfaces. The cracking of felspars and the forcing of serpentine into
them, which are frequently seen in thin sections of olivine rocks,
such as the troctolite shown in Fig. 34 on p. 304, shows on a small
scale the physical effect of expansion on serpentinisation, and
should lead us to expect a corresponding effect in rock masses. It
is thus not necessary to infer great tectonic movements to explain
the shattering of the rock, and in fact the disposition of the
serpentines in broad mountain tracts like Gebel Gerf is opposed
to the idea of there being here any local accentuation of folding
or crushing by general crust-crumpling. I have calculated that a
horizontal sheet of pyroxenite of sp. gr. 3·1, ten kilometres wide,
confined between fixed abutments and prevented from increasing its
thickness, would rise into an arch having a height of about two and
a quarter kilometres at its centre if converted into serpentine of
sp. gr. 2·6; this is, of course, not given as a precise example of
what may actually have taken place, but it will serve to show that
expansion on hydration may produce dynamical effects not inferior to
those of contraction of the earth’s crust, such as are believed to
be the main cause of mountain formation, and to explain why we may
find serpentines shattered to fragments and full of slickensided
surfaces in areas where the surrounding rocks show comparatively
little evidence of dynamo-metamorphism.
=Pyroxenites.=
Heavy dark green rocks, of medium to coarse grain, and consisting
almost entirely of a schillerized-looking mineral, form the
hill-masses of Gebels Um Ein and Qrein Salama, and similar rocks are
found in connexion with gabbro at Gebel Um Gunud and elsewhere. From
the diallagic appearance of these rocks in the hand specimen, they
were classed in the field as pyroxenites or diallage rocks. But
an examination of the slides cut from the specimens reveals the
main constituent to be hornblende, and the rocks must therefore
be placed in the division of amphibolites. It is, however, highly
probable that these rocks were originally pyroxenites, the hornblende
having originated mainly from the alteration of augite; the change
from augite to hornblende in the gabbros has already (p. 302) been
remarked, and in these ultra-basic forms the same process appears
to have gone on.
Some parts of the great ultra-basic mass of Gebel Gerf consist of
bronzite-rock. Specimens from the least altered portions consist
almost entirely of bronzite, sometimes with a little olivine;
the rocks are, however, generally found passing into serpentine,
such as forms the main portion of the mountain, and on microscopic
examination even the freshest portions always exhibit more or less
serpentinisation. It will accordingly be preferable to treat of
these rocks under the heading of serpentines.
=Amphibolites.=
Rocks consisting almost entirely of hornblende occur in considerable
masses in the neighbourhood of Gebel Um Gunud, and form the
conspicuous hills Gebel Um Ein and Qrein Salama; they also occur
in a small patch about three kilometres east of Erf el Fahid. In
the field, especially with the coarser-grained varieties, there is
often considerable difficulty in identifying the main constituent of
the rock as hornblende, owing to the schillerized appearance of the
mineral being more suggestive of diallage; the mass east of Erf el
Fahid, for instance, was classed in the field as a basic gabbro or
diallage-rock, instead of a very basic diorite or hornblende-rock,
such as the microscopic examination proves it to be. These rocks are
always very heavy and extremely tough; they weather commonly into
great rusty-looking rounded blocks, and a sledge hammer is required
to get a specimen.
[Illustration: Fig. 43.—Amphibolite, from hills near Gebel Um
Gunud [11,511], × 30. Almost the whole of the figure is occupied by
hornblende, which is seen clouded and altering to granular epidote
at _e_. Part of a large grain of calcite, bordered and streaked
with iron oxide, is seen at _c_, while _q_ is a small crystal of
interstitial quartz. The slide also contains a small proportion of
plagioclase felspar, not shown in the figure.]
The amphibolite of the hills about Gebel Um Gunud [11,511] is a very
hard and heavy coarse grained greenish-black rock composed almost
entirely of shining platey-looking crystals of hornblende, which often
reach two centimetres in length and breadth. The sp. gr. is 3·08. The
microscopic slide shows the rock to be granitic in structure and to
contain, in addition to hornblende, small amounts of plagioclase,
quartz, calcite, and iron oxides. The irregular-shaped hornblende
crystals show strong pleochroism, from pale olive-brown to moderately
deep green. The extinction angles are large, being frequently over
20°. Twinning of the crystals is fairly common. Many of the crystals
are clouded, and the alteration of the mineral has resulted in the
formation of much epidote. The plagioclase is only present in very
small quantity, strongly clouded by decomposition, but still showing
twinning clearly. The quartz is clear, and is likewise present in very
small proportion, mostly interstitial. Calcite is fairly plentiful
in large rounded and irregular grains, rather turbid-looking, of a
brownish or greenish tinge, outlined and streaked with strong lines
of iron oxide, in a way which at times suggests that the calcite
may possibly be the result of alteration of a lime olivine.
A specimen of amphibolite [11,528] obtained from a hill near the
junction of Wadi Abu Marwa with Wadi Naait, about seven kilometres
north-east of Gebel Um Gunud, is a dark green rock of rather fine
grain, made up of shining plates and small fibrous crystals of
hornblende and chlorite. Its sp. gr. is 2·97. Under the microscope
the hornblende is in rather ragged-looking irregular crystals of
various sizes, all interlocked with each other, rarely showing any
approximation to idiomorphism except in the smaller crystals, which
are commonly limited by prismatic faces; these smaller crystals are
frequently included in the larger ones. The pleochroism is fairly
strong, a pale olive brown, c moderately deep green. Prismatic
cleavage is well marked. Extinction angles are often large, ranging
up to 24°. A few of the crystals are slightly bent, and many show
more or less clouding owing to partial alteration to chlorite, but
on the whole the rock is fairly fresh. Except for a few specks of
magnetite, and the alteration product chlorite, the rock contains
nothing but hornblende.
The hornblende-rock or amphibolite of Gebel Um Ein [12,130] is
of medium grain, almost entirely made up of shining crystals of
hornblende with a little chloritic matter. The sp. gr. is 3·03. The
microscopic slide shows large individuals of hornblende inclining to
idiomorphism, set in a sort of ground mass of smaller crystals. The
hornblende shows the same strong pleochroism and high extinction
angles as in the two rocks just described; it is frequently clouded
and speckled with iron oxides, and often full of lighter-coloured
patches which extinguish with the rest of the crystal; in many cases
these lighter patches contain a central granule of iron oxide,
and they are doubtless due to a bleaching by segregation of the
iron. Between crossed nicols many of the crystals are full of small
fibres extinguishing differently from the rest of the crystal; some
of these fibres polarise in low colours and are probably chlorite
or serpentine, while others show brilliant tints and are possibly
actinolite.
The amphibolite which occurs three kilometres east of Gebel Erf el
Fahid [10,361] is of extremely coarse grain, looking like a very
basic gabbro owing to the schillerized appearance of its large
hornblende crystals and the presence of a little interstitial
felspar. The sp. gr. of the rock is 2·98. The section shows the
hornblende to be of a very pale green colour, with an almost entire
absence of iron oxide grains and other alteration products. Between
crossed nicols it has a fibrous woody appearance. The interstitial
plagioclase (probably labradorite) is likewise very fresh, showing
its repeated twinning very clearly; the crystals are full of tiny
fibres of hornblende, and are traversed by broad cracks filled with
a mosaic of smaller crystals of plagioclase and quartz.
[Illustration: Fig. 44.—Amphibolite of Qrein Salama [12,157],
× 17. _h_, hornblende, strongly striated, altering to chlorite;
_o_, olivine, and _b_, bronzite, both passing into serpentine.]
The rock [12,157], of the hill called Qrein Salama, to the east of
Gebel Gerf, is interesting as containing olivine and bronzite in
addition to the more abundant hornblende, and thus forming a link
between the amphibolites proper and the peridotites; but as about
three-quarters of the rock is hornblende it is still classed as an
amphibolite. The sp. gr. is 3·05. In the slide, the hornblende
is seen in irregular crystals, colourless to very pale green,
with a fibrous structure which is strongly marked by patches
of shading of extremely fine black prismatic striations. With
crossed nicols the fibrous structure is still more apparent,
the mineral polarising as brilliant fibres separated by chloritic
alteration products. The pronounced striation and faint colour of
the crystals are more suggestive of diallage than of hornblende,
but the extinction angles measured in the slide are all less than
22°. Many of the hornblende-crystals contain large numbers of
small rounded grains and strings of iron oxide. The olivine is
mostly in rounded crystals, frequently included in the hornblende;
it is largely serpentinised and full of small grains of opaque iron
oxides, but kernels of the original mineral remain. The bronzite,
which is present in about equal proportion with the olivine, is
likewise extensively serpentinised and full of iron oxide grains;
it is distinguishable from the olivine by a more fibrous appearance
(the serpentinisation having gone on mainly along the direction of
the vertical axis instead of along irregular cracks), and by its
generally lower polarisation colours in the unaltered portions.
=Peridotites.=
The peridotites, or felspar-free rocks consisting largely of olivine,
are usually classified into:—
(_a_) _Dunites_, consisting entirely of olivine.
(_b_) _Harzburgites_, consisting of olivine and enstatite or
bronzite.
(_c_) _Wehrlites_, containing olivine and diallage.
(_d_) _Lherzolites_, containing olivine, diallage, enstatite or
bronzite, and picotite or chromite.
(_e_) _Hornblende-picrites_, containing olivine and hornblende.
(_f_) _Mica-peridotites_, containing olivine and biotite.
Most if not all of these classes are represented in South-Eastern
Egypt, but in the altered form of serpentine. The change to serpentine
has been so complete that it is now hardly possible to extract even
a small specimen of the primitive rock; indeed, careful search is
often required to obtain even specimens containing any unaltered
mineral whatever, and one has frequently to rely on the structure
of the serpentine for the identification of the rocks from which
it originated.
=Serpentine.=
Serpentines cover about 400 square kilometres of South-Eastern Egypt,
forming the principal rock of several remarkable mountain groups
and also occurring in lower hill country.
The largest occurrence is that of the great mountain mass of Gebel
Gerf, where serpentine with alternations of gabbroid and dioritic
rocks can be followed from Bir Meneiga southward for some thirty
kilometres to beyond the Sherefa pass, while the breadth of the tract
from east to west is some fifteen kilometres or more at its widest
part; this tract includes a vast assemblage of high peaks and ridges,
towering up in many cases to more than a kilometre above sea-level. To
the north, south, and east, the serpentine is bounded by gabbros and
diorites, while on the west a tract of schistose rocks separates it
from another great serpentine mass which forms Gebel Korabkansi.
Other remarkable serpentine masses are Gebel Abu Dahr and the upper
part of Gebel Sikait; serpentines also enter into the composition of
Gebels Ghadir and Um Tenedba, while lower hills formed of similar
rocks occur near Bir Murra in Wadi Shait, in Wadi Um Khariga, near
Gebel Kalalat, and on the plain east of Abraq Springs.
The foxy red colour of exposed faces of serpentine hills, and the
generally shattered nature of the rock, have already been referred
to. When one approaches the masses closely, the red colour often
becomes less marked, because the fresh debris flanking the hills is
of a darker aspect. The slopes of serpentine hills are usually steep,
and this combined with the rotten nature of the rock renders their
climbing not always quite free from danger.
Any attempt to map out in the field the precise limits of the
different peridotites which were the parents of the serpentine ends
in failure, partly because the constituent minerals can generally
only be identified on microscopic examination, and partly because
the different peridotites pass gradually one into another, and are
evidently only produced by slight variations in the composition or
conditions of consolidation of a single magma. Even the limits of the
serpentine itself are not always very clear; for where the associated
rock is gabbro, as for instance to the north of Gebel Gerf, there is
a gradual passage through more or less serpentinised olivine gabbro
to the true serpentine. Golden yellow veinlets of fibrous chrysotile
can be seen running through the rock at many places, and occasionally
veins and pockets of magnesite and an inferior kind of asbestos occur
(_see_ p. 330).
The serpentines are nearly always more or less magnetic, and
sometimes show strong polarity. The compass was disturbed by
40° at the triangulation station on Gebel Sikait; the amount of
disturbance changes greatly when one moves even a short distance,
and all estimations of direction from compass readings in serpentine
country are therefore liable to enormous error.
In a strictly petrographical sense it would be most systematic to
describe the serpentines in classes according to the nature of the
parent rock; grouping together, for instance, all those derived from
pyroxenites into one class, those from amphibolites into another,
those from dunites into a third, and so on. But besides the fact
that the nature of the parent rock cannot always be determined with
certainty, such a course would possess the objection of separating the
different parts of one and the same mass; at Gebel Gerf, for example,
we have serpentines derived from rocks of various of these classes,
though probably all formed part of the same igneous intrusion and
are thus genetically connected. In the descriptions which follow,
therefore, the serpentines of each locality will be grouped together,
irrespective of origin. The localities are taken in order of latitude
from north to south.
[Illustration: Fig. 45.—Serpentine, probably derived from a
mica-peridotite, east of Erf el Fahid [10,360], × 40. _cm_, chlorite
and magnetite from alteration of biotite; _s_, clear serpentine,
probably altered olivine.]
A serpentine which occurs associated with amphibolite and various
schists about three kilometres east of Gebel Erf el Fahid [10,360]
may possibly have been derived from a mica-peridotite. In the
hand specimen it is a dark brown rock of dull aspect with greenish
patches, and shows marked magnetic polarity. The sp. gr. is 2·63. The
microscopic slide shows mainly colourless serpentine, but there are
strings and bundles of pale greenish-yellow chlorite, and specks and
strings of magnetite. The arrangement of the magnetite (_see_ Fig. 45)
at once attracts attention, being frequently aggregated in parallel
strings reminding one of the cleavage of mica. Between crossed nicols
the chlorite is easily distinguished from the serpentine by its
slightly higher polarisation-colours (low yellows as compared with
greys); and its arrangement in long leaves and bundles, with distinct
traces of the original mica, leaves no doubt as to its derivation
from biotite. The parallel strings of magnetite are also most likely
due to alteration of biotite, for it is difficult to account for
their peculiar arrangement otherwise; they are mostly separated by
material of lower double refraction than the chlorite above-mentioned,
perhaps a variety of chlorite poorer in iron, owing to the previous
separation of the oxide. The clear serpentine which forms the bulk
of the slide does not contain much iron oxide, and does not include
any trace of the original mineral from which it has been formed;
but between crossed nicols it shows an irregular mesh structure
which makes one almost certain of its derivation from olivine.
[Illustration: Fig. 46.—Serpentine, probably derived from
lherzolite, Wadi Um Khariga [10,368], × 17. _so_, serpentine derived
from olivine; _sb_ and _sd_ serpentine probably derived from bronzite
and diallage; _c_, calcite; _p_, picotite; _m_, magnetite.]
The serpentine of the hills on the west side of the Wadi Um Khariga
[10,368] is remarkable in the field by its foxy red colour on all
exposed surfaces. The rock, which has a sp. gr. of 2·63, is nearly
black on fractured surfaces, and no crystals can be detected in
it. The slide shows colourless to yellow serpentine, with a fair
amount of calcite often arranged along cracks, a liberal sprinkling
of magnetite, and one or two fairly large grains of picotite,
or chromite. In some parts of the slide the serpentine shows an
irregular mesh structure between crossed nicols; these portions,
in which the magnetite-granules show an irregular honeycomb-like
arrangement, are doubtless altered olivine. In other places the
serpentine polarises in clear greys with a fibrous aspect, and
the magnetite is arranged in parallel lines; calcite is typically
developed in these fibrous portions, sometimes along the cleavages
and sometimes in irregular patches. The fibrous-looking serpentine
probably represents the alteration-products of both rhombic and
monoclinic pyroxenes, and the parent rock was thus a medium-grained
lherzolite, containing olivine, diallage, bronzite and picotite.
In the hills on the east side of the Wadi Um Khariga, about in
latitude 24° 55′, there is some serpentine which has apparently
resulted from the alteration of very basic dykes. The sp. gr. is
2·65. A slide cut from this rock [10,367] shows the same clear
fibrous-looking patches as the specimen last described, and picotite,
in a confused and nearly isotropic mass of fine fibres of serpentine,
with but little magnetite and no calcite. No original mineral remains
except the picotite. The clearer fibrous patches may represent
diallage or bronzite, while the rest of the serpentine is somewhat
doubtfully referred to olivine. There is some trace of banding in
the rock, perhaps due to movement during consolidation.
A serpentine approaching an ophicalcite [10,376] forms the main
rock at Gebel Ghadir, where it is associated with a peculiar quartz
felsite resembling granulite. In the mass the rock, which has a
sp. gr. of 2·67, is black to green, veined with calcite; surfaces
of the debris are often covered with a brilliant green glaze. The
microscopic slide reveals an irregular mixture of nearly colourless
serpentine and cloudy-looking calcite, with abundant specks and a
few larger granules of slightly translucent deep-brown chromite or
picotite. Between crossed nicols, the serpentine is a mass of fibres
and little plates, in which a strong tendency to linear arrangement
can be seen, and here and there a lattice-structure. Though none
of the original mineral remains there is not much doubt that the
rock is an altered amphibolite or basic diorite; the calcite is
possibly derived from the alteration of an original lime felspar,
but it has been largely redistributed in the crushed rock by solution
and redeposition.
The serpentine forming the hills on the north side of the mouth of
Wadi Kalalat is a dark reddish-brown rock, of sp. gr. 2·76, in which
shining crystalline specks of olivine can be seen. It has doubtless
resulted from the alteration of a dunite, or rock consisting almost
entirely of olivine. The slide [11,510] shows the rock still to
contain abundant clear colourless kernels of the original olivine,
in a mesh-work of pale olive-brown serpentine. The serpentinisation
has taken place along irregular cracks in the olivine, each crack
being generally marked by a thin streak of opaque iron oxide
running longitudinally down its centre, with serpentine fibres
running crosswise and filling the rest of the crack. Where the
kernels first left have themselves become changed to serpentine,
they are nearly isotropic, while the cracks polarise in clear greys,
so that even where the whole of a crystal has been serpentinised the
structure is still clear, both in ordinary light by the magnetite
strings, and in polarised light by the way in which the serpentine
of the cracks stands out from the more isotropic patches within the
meshes. There is a little accessory diallage, easily recognisable by
its fibrous appearance and the oblique extinction of its unaltered
portions. The diallage, like the olivine, is passing into serpentine,
but here the serpentine goes on along cleavage planes as well as
along irregular cross cracks, giving the partially altered crystals
a striped appearance between crossed nicols. Where the diallage has
become entirely serpentinised, it can still be differentiated by its
clearer appearance from the olivine-serpentine in ordinary light,
and by its striated structure between crossed nicols; but of course
unless kernels of the original mineral are left one cannot be sure
whether it was diallage or bronzite. There are a few patches of
calcite or magnesite, and veinlets of the same secondary minerals;
these may have arisen from the alteration of a little original
felspar, or from the diallage.
Near the head of Wadi Arais, to the south of Gebel Um Bisilla,
there are some dykes of dark magnetic rock of sp. gr. 2·56. A
specimen from one of these dykes [11,519], turns out on microscopic
examination to be a schistose serpentine. It is traversed by parallel
strings of opaque and brown translucent iron oxides, and granules of
magnetite are also scattered over the interspaces. The interspaces
between the iron oxide strings are filled with serpentine showing no
recognisable structures, but containing here and there little nests
of clouded green hornblende, suggesting the possibility of the rock
being an altered basic diorite or amphibolite.
The highly crushed and rotten serpentine which forms the high and
steep-sided mountain mass of Gebel Abu Dahr, differs considerably in
composition in different parts. The most typical form of the rock,
which has a sp. gr. of 2·77, is a dark brown serpentine with little
strings of olive-green matter, and occasionally large dulled black
crystals. A slide [11,516 A], cut from this portion of the rock
shows mostly olivine, altering to serpentine in the usual manner
with abundant clear kernels of the original mineral. Associated with
the olivine is another mineral of a somewhat fibrous aspect, altered
partly to serpentine and partly to another substance which polarises
as a confused aggregate of fibres and flakes in brilliant colours,
the flakes extinguishing with slight obliquity; the serpentine is
formed mainly along the vertical cleavages of the mineral (though it
also fills transverse irregular cracks), while the other substance
(tremolite?) fills up interspaces. In some parts of the mass the
rock has a blacker colour and a slightly higher density (2·87),
somewhat resembling a basalt with large greenish fibrous-looking
crystals scattered sparsely through it. The slide cut from this form
of the rock [11,516 B] shows no olivine whatever, practically the
whole slide being composed of the fibrous mineral just described,
together with a little nearly colourless fibrous hornblende, in
which the change above-mentioned appears to be going on. Thus it
would seem likely that the rock of Gebel Abu Dahr is essentially
an altered hornblende-picrite (or olivine-hornblende rock) with
variations towards dunite (olivine-rock) on the one hand, and towards
an amphibolite or hornblende-rock on the other. The alteration of
hornblende here is not a purely serpentinous one, but results in
the formation first of serpentine along cracks and cleavage planes,
and then of a tremolitic mineral in the interspaces. It is worth
remark, moreover, that in the slide free from olivine the change to
tremolite preponderates, and there is much less serpentine in the
altered hornblende than in the slide containing olivine; this suggests
that the presence of the neighbouring olivine has in some way brought
about more serpentine in the hornblende, perhaps by actual forcing of
serpentine from the expanding olivine into cracks in the hornblende,
or by the influence of pressure set up by the same expansion.
In the serpentine from some low hills on the plain a little to
the east of Bir Abraq [11,506] we have a rock evidently derived
from a dunite, though not a trace of unaltered olivine remains. The
sp. gr. is 2·61. The microscopic slide consists of nearly colourless
serpentine with strings of magnetite marking the cracks along which
its formation began (_see_ Fig. 47). Between crossed nicols (_see_
Fig. 48) the main portion of the serpentine, doubtless derived
from olivine, presents a very remarkable appearance; most of the
polygonal spaces between the magnetite-meshwork are lined with plates
of clear serpentine, while the centre is occupied by nearly isotropic
material. Thus the slide in polarised light presents somewhat the
aspect of an aggregate of cells with dark nuclei. Besides olivine, the
slide shows a small amount of a fibrous mineral, probably bronzite,
which is likewise almost entirely altered to serpentine, though a
few original fibres remain; the magnetite grains in the serpentine
derived from this mineral is typically aggregated in strings parallel
to the fibres.
[Illustration: Fig. 47.—Serpentine derived from an almost pure
olivine-rock, from a low hill east of Bir Abraq [11,506], × 17. The
outlines of the original olivine crystals (_o_) and the cracks in
them are marked by granules and strings of magnetite. A serpentinised
crystal of bronzite is seen at _b_.]
[Illustration: Fig. 48.—A small portion of the serpentine derived
from olivine in the same slide, viewed between crossed nicols under
a higher power, showing the cellular structure.]
A serpentine rock found associated with fine-grained diorite at
Gebel Um Tenedba [11,517 B] may have been derived from an olivine
diabase poor in felspar. The rocks in this locality are highly
altered and crushed, and frequently more or less schistose. In a
slide cut from the serpentine of the lower part of the mountain,
which has a sp. gr. of 2·71, all the original minerals of the
rock have been replaced by alteration products. The main portion
of the slide is probably altered augite; it consists of serpentine
with fairly distinct mesh structure in which iron oxides are very
abundant in clots and strings. Some patches, which show a more uniform
grey aspect under crossed nicols, are doubtfully referred to altered
felspar. Smaller areas, usually free from iron oxide grains and mostly
consisting of almost isotropic serpentine with a substance polarising
in low yellow tints running along irregular cracks in all directions,
are believed to represent altered olivine; one of these areas is
nearly filled with little brushes of the substance just mentioned,
giving it almost a spherulitic appearance as the nicols are rotated.
[Illustration: Fig. 49.—Serpentine, derived from wehrlite, Gebel
Gerf [12,128], × 17. _s_, serpentine (mainly altered olivine, with
strings of magnetite); _o_, unaltered olivine, mixed with granules
of augite; _d_, diallage.]
The predominant rock of the mountain mass of Gebel Gerf [12,128] is
a serpentine apparently derived from a wehrlite or olivine-diallage
rock. In the hand specimen, it is a rather heavy black rock
(sp. gr. 2·75) with small pea-green spots and a few small bronzy and
glassy looking crystals here and there. The microscopic slide (_see_
Fig. 49) shows the olivine to be largely altered to serpentine in
the ordinary manner with separation of magnetite, but some granules
of the original mineral remain, especially aggregated, together
with augite granules, round the diallage crystals. The diallage is
tolerably fresh, and easily recognisable by its fine striation and
oblique extinction. Besides the diallage, there is some ordinary
augite, not always very easily distinguishable from the unaltered
olivine owing to its cleavage not being very marked. Some of the
diallage crystals show undulose extinction as the result of strain.
[Illustration: Fig. 50.—Serpentinisation of bronzite, as seen
in a serpentine derived from bronzite-rock, Gebel Gerf [12,119],
under a high power between crossed nicols. The clearer portions
of the figure are unaltered portions of a single large crystal of
bronzite; the serpentine is seen forming mainly along the cleavages
of the original mineral, with subsidiary cross-fibres.]
At many points the serpentine of Gebel Gerf contains a great
deal of bronzite, crystals of this mineral of typical aspect and
measuring up to five millimetres diameter being visible in the hand
specimen scattered liberally through the duller serpentine. The
sp. gr. of this portion of the mass is 2·81. The slide [12,119]
shows practically nothing but bronzite altering to serpentine,
so that locally the parent rock has been a pyroxenite rather than a
peridotite. The serpentinisation of the bronzite has proceeded mainly
along the fibres of the original mineral, but there are numerous
cross-fibres (_see_ Fig. 50), and here, as in the hornblende of the
rock of Gebel Abu Dahr, the change to serpentine appears to have
been accompanied by the production of tremolite. In another slide
[12,127] the main constituent appears to be still bronzite, but
here it is of a pronounced olive-brown colour even in thin section,
and is accompanied by some nearly colourless diallage; some of the
olive-brown fibrous crystals show extinction-angles of a few degrees,
and it is possible that these are hornblende.
Though the greater part of the Gerf serpentine has been derived from
rocks free, or practically free, from felspar, it is possible that
these were mixed with other rocks, such as gabbros and diabases, in
which basic plagioclase formed an essential constituent. One of the
specimens brought back from the mountain [12,115], having a sp. gr. of
2·67, is a somewhat wedge-shaped block, about ten centimetres square
and four centimetres thick, covered entirely with the shining black
to greenish glaze which is characteristic of shattered serpentine,
except where chipped with the hammer to test its coherence and to
look for remains of crystals in it. The fractured surface is mostly
dull and nearly black, with little strings and spots of greenish
matter and scattered shining specks. But although the block so
thoroughly resembles a serpentine, the slide cut from it proves the
rock to be a fine-grained diabase, consisting essentially of augite
and plagioclase, with a good deal of iron oxide. The plagioclase
is tolerably fresh, in lath-shaped forms still showing twinning
very clearly, while the augite is very clouded and is changing to
hornblende and chlorite or serpentine. In the field nothing was
noted which would separate this rock from the rest of the mass,
which it resembles almost perfectly in appearance, and whether the
diabase forms a dyke or sheet, or the specimen represents a fragment
of diabase caught up by the magma, is not certain. A dyke of this
material, shattered and serpentinised on all the fractured surfaces,
would be indistinguishable from the surrounding serpentine. It is
even possible, though not likely, that the diabase is not a separate
intrusion, but merely a variation of the same plutonic mass which
has given origin to the main bulk of the serpentine.
Other variations in the serpentine which point to parts of the Gerf
mass having originally been of a gabbroid type, occur in the mountains
round Bir Korbiai and Bir Meneiga. A specimen from near Bir Korbiai
[12,125], is a greyish-black fine-grained rock full of little white
and greenish specks and strings, with pale citron-green serpentinous
matter covering the slickensided surfaces of the fragments into which
the mass readily separates. The sp. gr. is 2·67. The microscopic
slide shows serpentine with pronounced knitted structure in places,
as though derived from augite, and considerable patches of calcite
which may represent an original lime-felspar. The calcite has,
however, been largely redistributed along cracks, where it is often
mixed with extremely coarse fibres or plates of serpentine.
The specimen from the mountains round Bir Meneiga [12,104] is a
hard dull slatey-grey rock with black streaks and spots; it is
strongly magnetic and shows a tendency to schistose structure. The
sp. gr. is 2·54. On examination with a lens the grey matter has
in places something of a resemblance to saussuritised felspar. The
slide cut from this specimen contains no original minerals. The
bulk of it seems to be composed of very minute fibres or plates,
generally showing a distinctly parallel arrangement along the planes
of schistosity, but exhibiting knitted structure in places, and thus
probably consisting in part of kaolinic matter derived from altered
felspar, and in part of serpentinous matter derived from alteration
of augite; while scattered through the slide are abundant patches and
strings of calcite and magnetite. The rock is too intensely crushed
and altered for one to be certain of its origin, but it appears to
have been originally a diabase.
[Illustration: Fig. 51.—Serpentine derived from alteration of
harzburgite, Gebel Korabkansi [12,140], × 17. _s_, serpentine,
mostly formed from olivine; _o_, unaltered olivine; _b_, altering
bronzite; _c_, chromite or magnetite, enveloping olivine.]
The serpentine of Gebel Korabkansi, to the west of Gebel Gerf,
is an altered olivine-bronzite rock (harzburgite) of moderately
coarse grain. A slide [12,140] cut from the least altered portion,
where the sp. gr. of the rock is 2·72, shows olivine to have been the
most abundant constituent; it is largely serpentinised in the typical
manner, but abundant kernels remain unaltered. Mixed with the olivine
crystals are others of a fibrous mineral, altered partly to serpentine
and partly to a confused mass of tremolite fibres; in the few cases
where any of the original material remains, this fibrous mineral shows
straight extinction, and is probably bronzite. The alteration of the
pyroxene has here proceeded more rapidly than that of the olivine. The
pyroxenic mineral is easily picked out in the slide by ordinary light,
owing to the fact that the olivine has altered to greenish-yellow
serpentine, while the mixed material produced from the pyroxene
is of a dirty-white aspect. Another slide from Gebel Korabkansi
[12,112] exhibits in places mesh-structure with clear kernels which
extinguish very obliquely to the meshes, showing augite or diallage
also to have been a constituent of the parent rock; and there is
a single ragged-looking crystal of dark green fibrous hornblende,
altering to nearly colourless serpentine. The sp. gr. of the specimen
from which this latter slide was cut is 2·63. Both the slides from
Gebel Korabkansi are rather poor in iron oxides, but there are a
few irregular crystals of chromite, generally enveloping olivine.
=Alteration Products of Serpentine. Magnesite and Asbestos.=
In many of the serpentine-masses the effects of solution and pressure
can be traced in the formation of veins and pockets of magnesite,
asbestos, and occasionally talc in the rock. Magnesite veinlets
are frequently seen, for instance, round about Bir Meneiga [12,142]
and Bir Muqur, while asbestos has been found in pieces of several
kilogrammes weight in the Wadi Sherefa el Sherqi [12,122] and near
Bir Muqur [12,153]. At the last-named locality it occurs along the
crush-planes of the serpentine, and appears to be preceded by the
formation of long fibres of a green substance.[133] Where thickest,
the glaze on the slickensided surfaces of the serpentine fragments
seems to consist of this same green substance, which splits into hard
fibres often reaching ten centimetres or more in length and only a few
millimetres in diameter [12,153 A] and these hard fibres, which have
a sp. gr. of 2·64, break up gradually, apparently under weathering
influences, into the much finer and more flexible fibres of white
asbestos. The quality of the asbestos is, however, inferior, for a
specimen of the softest kind sent to London for an expert opinion,
was reported to be of no commercial value; even had it been otherwise,
the quantity seen was too small to justify working, though of course
a thorough search among the mountains might reveal the presence of
bigger deposits than were encountered during the survey.
[Footnote 125: From _Marwa_, the Arabic term for quartz.]
[Footnote 126: The numbers in square brackets in this and the
following chapter are the registration numbers of the specimens in
the Geological Museum, Cairo.]
[Footnote 127: I may here recall that the quartz mass which
constitutes the so-called “alabaster” quarry north of Aswân,
and for which I have inferred an igneous origin, is likewise closely
associated with aplitic or pegmatitic intrusions. See _A Description
of the First or Aswân Cataract_. Cairo, 1907, p. 84.]
[Footnote 128: This specimen was brought back by a guide sent for
the purpose to Gebel Adar Qaqa. It is stated to be the main rock
of the mountain, but as I did not visit the mountain I am unable to
vouch personally for this being the case.]
[Footnote 129: From a specimen brought back by the guide who was
sent to erect the triangulation beacon on Gebel Mishbih.]
[Footnote 130: I did not visit Gebel Shendib, but as seen from Gebel
Elba the mountain appeared to be granite; the felsite probably forms
a dyke passing through the summit.]
[Footnote 131: There is another Gebel el Anbat near the Wadi Hodein,
but this latter consists of schists.]
[Footnote 132: Preliminary Report on the Geology of the Eastern
Desert of Egypt, between latitude 22° N. and 25° N., by
Dr. W. F. Hume. Cairo, 1907. p. 57.]
[Footnote 133: This fibrous green substance is probably the columnar
variety of serpentine known as _Picrolite_; it strongly resembles the
specimens thus labelled in the London Museum of Practical Geology.]
CHAPTER X.
* * * * *
=METAMORPHIC ROCKS.=
* * * * *
Metamorphic rocks, comprising a great variety of gneisses and schists,
are widely and abundantly distributed in South-Eastern Egypt,
forming about half the entire area treated of in this volume. The
irregular way in which the metamorphic rocks alternate with those
of the igneous and sedimentary groups will be better appreciated
by a reference to the geological map on Plate XX than by any verbal
description. As a whole, the metamorphic rocks represent the remains
of a complex of igneous and sedimentary deposits which were laid
down in remote geological periods; subsequently these deposits
were crushed, folded, and elevated into mountains, their original
structures being largely obliterated in the dynamical process;
in succeeding ages the metamorphosed complex was penetrated by the
great granitic and other intrusions which have been described in
the preceding chapter, and then planed down by denudation as an
old land surface before being wholly or in part submerged beneath
the waters of the Cretaceous sea in which the Nubian sandstone was
deposited. The elevation of the land after the Cretaceous period
was accompanied by further folding which must have increased the
degree of metamorphism of the rocks; but it is most probable that
the forces which produced these post-Cretaceous movements were of
less intensity and duration than those of more ancient periods,
and we may regard the metamorphic character of the older rocks
as having been for the most part impressed on them in Archæan,
or at latest in Palæozoic times. It is not impossible that some
of the more highly foliated gneisses may even have been parts of
the primitive crust of consolidation of the earth, while the clay
schists may be the remains of the very earliest sediments.
Besides the evidences of dynamo-metamorphism above-mentioned, we find
occasionally traces of contact-metamorphism, where igneous dykes
have locally altered the rocks into which they have intruded; but,
in general, the subsequent compression of the masses has obliterated
these traces, and the effects of contact-metamorphism are negligible
in comparison with those produced by dynamic action.
The metamorphic rocks occurring in this part of Egypt may be
classified as follows:—
=Gneisses.=
_Granite-gneiss_ (crushed granite).
_Diorite-gneiss_ (crushed diorite).
_Highly foliated gneisses_ (in which all traces of primitive
structure have been obliterated by foliation and recrystallization).
=Schists.=
_Quartz-schists_ (in some cases probably metamorphosed sandstone,
in others crushed aplitic rocks).
_Clay-schists_ (metamorphosed clays).
_Hornblende-schists and crushed volcanic rocks._
_Hornfels_ (metamorphosed acid lavas).
_Mica-schists_ (sometimes containing beryl and tourmaline).
_Chlorite-schists._
_Talc-schists._
_Calcareous schists and marble._
_Graphite-schists._
=Breccias.=
_Fluidal breccias_, in which broken fragments of solid rock have
been included in an intrusive magma.
_Breccias proper_, formed by fracture and recementing together
of fragments without fusion.
=Mineral Veins.=
_Quartz veins_ (sometimes containing gold and traces of copper).
_Calcite veins_ (with more or less chalybite).
_Magnesite veins_ (in serpentine).
_Asbestos veins_ (in serpentine).
=Gneisses.=
The most conspicuous occurrence of gneiss in South-Eastern Egypt is
the great mass which extends from Gebel Mudergeg and Gebel Migif in
the north, down the range of Gebel Hafafit, and along the greater part
of the Wadi Gemal. With this mass is closely connected another stretch
of gneiss to the south of Gebel Abu Khrug; the hills which rise from
the sandy plain round the head of Wadi Natash are mostly gneiss, so
that the gneiss is probably continuous across the plain except where
it is penetrated by the syenitic cones called El Nahud. The total
area covered by gneiss in this locality alone is some two thousand
square kilometres, and includes some remarkable mountain masses,
such as Gebels Migif and Hafafit.
Other gneissose areas of less extent occur round Bir Abu Beid and to
the south-west of Gebel Hamrat el Feg; while still smaller areas are
found in the hills to the north-west of Berenice, in the remarkable
triple-headed mountain called Gebel Um Rasein, and to the north of
Bir Um Bishtit.
Gneiss typically forms bold scenery of precipitous hills, the
colour of which varies with the composition of the rock, from pink
to grey. At Gebel Migif one ascends the mountain most easily by the
northern slopes, which are formed by the foliation-planes of the
rock, while to the south these are cut across by sheer precipices;
the same is the case at Gebel Um Rasein.
[Illustration: Fig. 52.—Granite-gneiss, Gebel Um Rasein [12,108],
viewed between crossed nicols, × 30. _q_, quartz; _ol_, oligoclase;
_or_, orthoclase; _h_, hornblende; _m_, “mortar” of crushed
quartz and felspar between the larger crystals. The black areas are
quartz in the position of extinction.]
Of gneisses evidently produced by the deformation of granite, we
may take the rock of Gebel Um Rasein [12,108][134] as a type. The
bulk of the mountain is formed of a nearly white acid rock, of
sp. gr. 2·67, with dark spots, resembling the granite of Gebel
Elba in appearance, except that here the dark minerals have a marked
arrangement along definite planes. (Compare the coloured figures of
the two rocks on Plates XXII and XXV). In places the rock contains
thin bands of almost pure biotite, and these are often thrown into
sharp contortions by the strong compression which the mass has
undergone. The strike of the foliation-planes in Gebel Um Rasein
itself is about south-south-east, with a dip of about 20° to the
east-north-east, but the strike swings round to about south at the
south end of the mass, and the inclination of the foliation-planes
become much steeper. The gneiss shows very marked pitting due to
weathering, the holes ranging from a few centimetres to a metre or
more in diameter and depth. A microscopic section of the rock shows
it to be essentially an acid hornblende-granite similar to that of
Gebel Elba, but crushed so that there is a “mortar” of broken up
quartz and felspar between the larger crystals, and the larger where
unbroken frequently show undulose extinction as the result of strain.
[Illustration: Fig. 53.—Diorite-gneiss, Wadi Nugrus [10,386], ×
17. _h_, hornblende, with small enclosures of felspar and sphene;
_pl_, plagioclase felspar; _b_, biotite; _q_, quartz; _ap_, apatite;
_sp_, sphene.]
In the Wadis Nugrus and Gemal there is a great deal of strongly
foliated grey gneiss [10,386-7], derived from the intense crushing
of diorites. A figure from a typical hand specimen of this gneiss,
looking at the edges of the foliation-planes, is given on Plate
XXV. The sp. gr. of the rock is 2·88. The microscopic slides show
plagioclase and green hornblende in about equal proportions, with
some quartz and small amounts of biotite, sphene, iron oxides, and
apatite. The hornblende is very fresh-looking, in strongly pleochroic
(yellowish to deep blue-green) straggling crystals, aggregated
together along the foliation-planes; the crystals, though variously
oriented, show a tendency to lie with their cleavages in the direction
of foliation. A very striking feature of the slides is the abundance
of small grains of enclosed felspar in the hornblende, giving
the green crystals a perforated appearance in ordinary light. The
felspars, which are likewise fairly fresh, are much smashed up,
forming with the quartz a mosaic between the irregular bands of
hornblende; the grains often show undulose extinction. Biotite,
of a warm brown colour where not bleached, is sparingly mixed with
the hornblende. The sphene is in small rounded grains, mixed with,
and sometimes containing, granules of ilmenite; the grains show a
tendency to form little aggregates, sometimes in the hornblende,
and sometimes in the felspathic portions of the slide. One or two
stumpy grains of apatite are enclosed in the felspars, but this
mineral is extremely scarce in the slides examined, and does not
show its usual long prismatic habit.
=PLATE XXV.=
[Illustration: Ball.—Geography & Geology of South-Eastern Egypt.
=METAMORPHIC ROCKS.=
=GRANITE-GNEISS.= Gebel Um Rasein.
=RED GNEISS.= Gebel Abu Beid.
=DIORITE-GNEISS.= Wadi Nugrus.
=GREEN BRECCIA.= Gebel Hamata.
=EMERALD AND QUARTZ IN MICA-SCHIST.= Gebel Sikait.
NATURAL SIZE.]
As an example of gneisses in which the foliation is so intense that
all original structures have been obliterated by recrystallization,
we may take the red gneiss of the Abu Beid Hills [10,659], of which
a coloured natural size representation is given on Plate XXV. In
this rock, which has a sp. gr. of 2·65, the main constituent is
a pink felspar, mixed with a little quartz and arranged in fine
lenticles separated by greenish laminæ which are doubtless altering
biotite. This rock bears a strong resemblance to the well-known
red gneiss of the Erzgebirge, which, from its chemical composition,
is usually believed to be a metamorphosed granite poor in mica.
Grey gneisses, equally intensely foliated with the Abu Beid rock,
occur in the range of Gebel Hafafit; these contain a much larger
proportion of biotite, and remind one of the grey gneisses of the
Freiberg district. But as no analyses have yet been made of the
Egyptian rocks, the absolute similarity to those of the Erzgebirge
is not quite certain.
=Quartzites and Quartz-schists.=
About ten kilometres south of Gebel Abu Gurdi is a tract of low
hills and ridges composed mainly of quartz-schists. The limits
of these rocks have not been mapped, but they appear to cover a
somewhat elliptical area with its long axis, measuring some eight or
ten kilometres, pointing east and west. Where first encountered,
at a point about twelve kilometres east of Gebel Selaia, on
the march from that hill towards the pass into the head of Wadi
Lahami, the rocks strongly resemble rather friable white to brown
fine-grained sandstones, with bedding planes dipping about 35° to
the north. The rock [10,413] consists almost entirely of white or
slightly iron-stained quartz grains, with, in places, scattered
minute dull black rods which are apparently hornblende. Traced
further east, the rocks have more and more the character of
quartz schists, with harder bands of quartzite, and the planes of
separation, which gradually become nearly horizontal, have more the
appearance of foliation-planes. The harder quartzite bands [10,414]
are usually brownish to greenish-white in colour, but sometimes take
on a purple tint, and show micaceous and chloritic scales on cleaved
surfaces; in some places the rock contains “eyes” of minette-like
composition. To the south the bedding or cleavage planes seem to
reverse their dip, this being now to the south as though there were
an anticlinical fold in the mass. There is considerable mixture of
other schists with the rocks, and dykes of diorite and pegmatite,
as well as veins of quartz, are frequent. A dioritic dyke which
cuts through the rocks at a point nine kilometres south-south-west
of Gebel Abu Gurdi, and which is itself crushed almost into a
hornblende-schist, has hardened and altered the quartzose rock on
either side of it into a close-grained horny looking rock [10,415]
apparently containing a great deal of finely granular andalusite.
These quartz-schists may have arisen from the metamorphism either
of sandstones, in which case the parts to the west of the tract
are the least altered, or of fine-grained aplitic rocks, on which
view the sandstone-like aspect of the western portion of the tract
is due to weathering; the rock is certainly more highly weathered
where it most resembles an unaltered sandstone, and the presence of
hornblende and the “eyes” of micaceous matter are suggestive of
igneous rock. From a consideration of all the evidence I was able
to gather in a rapid march over the sea, however, I incline to the
view that the rocks are altered sandstone older than the Nubian
series, and probably of about the same age as the ancient clays
which gave rise to the clay-schists of Zabara and elsewhere. The
rocks are completely detached from the nearest undoubted Nubian
sandstone beds (which lie some forty kilometres to the south-west,
beyond Gebel Zergat Naam), and they are mixed with schists and veined
and altered to a degree which is nowhere approached by beds known
to be of the Nubian series. Still, it is just possible that the
quartz-schists represent the remains of Nubian sandstone strata,
for the nearest beds of that series show-considerable folding and
faulting near Gebel Zergat Naam, and we should expect still greater
disturbance and alteration here near the main watershed and close
to a principal axis of mountain elevation.
A quartz-schist which is certainly derived from the metamorphism
of aplitic dykes or sheets, occurs as great inclined bands cutting
across the Wadi Shenshef close to some old ruins. The main rock of the
district, in which the bands occur, is a medium-grained diorite. The
quartz-schist is a greyish-white fissile rock, which splits easily
into great slabs; it has supplied an excellent building material
for the houses of the ruined town or encampment, being used not only
for the walls but also for lintels over doors and windows.
=Clay-schists.=
Clay-schists cover extensive areas in the South-Eastern Desert. They
occur abundantly in the high hills to the east of Gebel Nugrus and
form a large portion of Gebel Zabara. They abound also to the south
of Wadi Antar about the longitude of Gebel Um Goraf, in the hills
on the east side of Gebel Abu Dahr, in the Wadi Hodein round about
where Wadi Um Tenedba joins it, in the hills flanking the sandstone
plateau of Gebels Dif and Anfeib, at Gebels Kolaiqo and Eqrun,
on the western flanks of the serpentine mass of Gebel Meneiga,
and in the low hills on the plain between Gebels Gerf and Korabkansi.
Clay-schists are typically of a grey colour, though greenish, purple,
and reddish varieties occur. They are soft rocks, easily scratched
with a knife. In some places, as for instance at Gebel Zabara, they
are practically slates, cleaving into slabs often of considerable
size, while in other localities, as for instance near Gebel Abu Dahr,
they are crushed into matchwood-like splinters, which can be used
as slate-pencils. They are usually associated with other metamorphic
rocks such as crushed diorites and hornblende and mica-schists. The
direction of foliation of the slaty and slabby forms is often
persistent—at Gebel Zabara, for instance, a general south-easterly
dip of about 28° is maintained over a considerable area; but there
are numerous local variations, and the number of observations thus
far made is too small for any general conclusions to be drawn as to
the regional distribution of dip. On the whole, the clay-schists are
remarkably free from knots or other irregularities, though knotted
varieties, doubtless the result of contact alteration, have been
observed on the south side of Wadi Seiga and at a few other places.
The clay-schists have probably for the most part been produced by
the metamorphism of ancient argillaceous sediments; in some places,
as for instance in the Wadi Beida, a passage can be observed
into what appears to be a crushed conglomerate, while in other
places they pass into quartzites which doubtless represent altered
intercalated sandstones. The relation between the direction of the
foliation-planes and that of the original bedding is unknown; it
would appear likely that in most cases the traces of bedding have
been entirely obliterated by pressure. Nor have any fossils been
found in the rocks, though a sharp look-out was kept in the more
likely-looking localities, so that the age of the beds is unknown. At
present I am inclined to regard them as most likely of Archæan age,
antedating the great granitic intrusions; but further evidence,
either in the finding of fossils or from a more careful study of
the field relations of these rocks to the others, is required before
one can be certain that they are of so great an antiquity.
=Hornblende-schists and Crushed Volcanic Rocks.=
Under the heading of hornblende-schists and crushed volcanic rocks are
classified a great variety of rocks, ranging in colour from green to
grey and almost black, in fissility from the finest lamellation to
almost massive forms in which the schistosity is barely evident in
the hand specimen, but all definable as fine-grained dark-coloured
schistose rocks consisting largely either of hornblende or of its
alteration products. Their origin is not always clear, but many of
them appear on microscopic examination to be altered fine-grained
syenites, diorites, and lavas, and it is probable that practically
the whole are altered forms of various intermediate and basic igneous
rocks. The reason for including the hornblende-schists and crushed
volcanic rocks in one great group is the difficulty of separating
the different classes in the field. They pass one into the other,
and many rocks which in the field would be put down as hornblendic
turn out on detailed examination to contain little or none of that
mineral, its place being taken by decomposition products.
Schists of the types above defined occur probably more abundantly
than any other class of metamorphic rocks in the South-Eastern
Desert. They enter largely into the composition of some of the
main mountain masses, such as those of Gebels Abu Hamamid and Abu
Gurdi, besides covering great expanses of lower hill country. In
the mountain ranges they rise in steep-sided ridges with knife edge
summits, a good idea of which is given by the photograph of Gebel Abu
Hamamid on Plate VII. In the lower hill country we have typically a
dreary confused looking waste of thousands of dark hills and ridges
separated by small winding wadis; sometimes there is a semblance of
system in the distribution of the hills, owing to the occurrence
of parallel dykes harder than the schists which they penetrate,
forming thus back-bones for long lines of schist-ridges.
[Illustration: Fig. 54.—Schist produced by crushing of syenite,
near Gebel el Anbat (Wadi Hodein). [11,532 B], × 30. _f_, crushed
and clouded felspar, probably orthoclase; _lc_, mixture of calcite
and limonite, produced by alteration of hornblende, no trace of
which remains.]
=Schist derived from Syenite.=—Among the schists occurring
near Gebel el Anbat, near the Wadi Hodein, is one which appears
to be a crushed and altered syenite. It is a speckled grey and
reddish-brown rock with a dull and rather granular fracture, of
sp. gr. 2·92. The slide [11,532 B] shows a rather coarse granitic
mixture of clouded felspar and heavily iron-stained calcite. The
felspar is considerably altered, showing no twinning, but between
crossed nicols it extinguishes in irregular bands and is seen to
be much crushed. The ferruginous and calcareous matter is almost
certainly altered hornblende; it forms irregular masses, in which the
iron oxide is mostly arranged in parallel lines as though along the
cleavage planes of the parent mineral, while a clouded calcite fills
up the spaces between the lines. It would seem that in addition to
pressure, carbonic acid has been the main agent of metamorphism here,
the ferro-magnesian silicate being attacked and its silica entirely
removed, while the aluminous silicate of the felspar has remained
to some extent unchanged.
[Illustration: Fig. 55.—Hornblende-schist (probably a metamorphosed
fine-grained diorite), Wadi Muelih [10,357], × 40. _h_, pale green
hornblende; _f_, mass of decomposed felspar, containing abundance of
finely acicular hornblende and some little patches of quartz mosaic;
_m_, magnetite.]
=Schists derived from Diorites.=—Hornblendic schists which appear
to have been produced by the metamorphism of fine-grained diorites
occur largely in the low hill country round the upper parts of
the Wadi Muelih, and in the mountain mass of Gebel Abu Gurdi. A
specimen of the less altered rock from the Wadi Muelih [10,357] is
a fine-grained hard grey basaltic-looking rock, of sp. gr. 3·04,
in which the schistosity in not very evident, though it is well seen
in the mass. The microscopic slide shows pale green hornblende in
ragged fibrous forms in a matted-looking clouded ground mass made up
of finely acicular green hornblende and plagioclase, with a little
quartz and orthoclase and a few grains of magnetite. Hornblende fibres
are often enclosed in the decomposing felspars, which rarely show
definite outlines and appear much shattered. The quartz is probably
of secondary formation, occurring as little patches of mosaic.
The schist which forms the summit of Gebel Abu Gurdi [10,416]
is probably also a crushed and altered diorite; it is a rather
fine-grained hard greenish-grey rock, which with a lens can be seen
to be a mixture of greenish-white felspathic material and dark
hornblende; the felspar is mostly dull, while the hornblende, on
the other hand, is frequently in shining crystals. The sp. gr. of
the rock is 3·02. The microscopic slide shows the hornblende
to be of a very pale green colour, in large irregular crystals,
often including felspars. The felspar appears to be plagioclase;
it is typically in smaller crystals than the hornblende, with a
strongly marked tendency to idiomorphism, highly cracked and almost
entirely changed to kaolin. Some rather large straggling crystals
of a dark brown clouded and semi-opaque highly refracting mineral,
white by reflected light, are perhaps altered sphene. Round the
larger crystals is more finely crystalline matter, much clouded,
apparently composed of altered felspar and hornblende.
The crushed dioritic dykes already mentioned as cutting the
quartz-schist to the south-west of Gebel Abu Gurdi are possibly
offshoots from the same magma which formed the main mass of the
mountain. Specimen [10,415], taken from one of these dykes, is a
fine-grained grey rock, of sp. gr. 2·93, with an even more decided
schistosity than that of the main mountain. The microscopic slide
shows clear hornblende of a green colour, strongly pleochroic
(greenish-yellow to blue-green) in irregular grains which are
frequently aggregated into nests and strings running in the direction
of foliation of the rock; the remaining material is a mosaic of
clear quartz, clouding kaolin, and sericite, presumably representing
altered felspar.
[Illustration: Fig. 56.—Schist composed of fragments of various
volcanic rocks, summit of Gebel Abu Hamamid [10,397], × 30.]
=Schists formed by crushing of Volcanic Rocks.=—Schists derived
from the crushing of volcanic rocks are very abundant in the mountains
round Gebel Abu Hamamid and in the Wadi Beida. Typical specimens from
the summit of Gebel Abu Hamamid [10,397] are hard green to grey rocks,
of sp. gr. 2·7, breaking with a rough dull fracture. With a lens,
spots and strings of dull white matter, with ill-defined outlines, are
seen in a green to nearly black ground mass. The microscopic slides
show the rock to be a breccia rather than a simple crushed rock,
for in the same slide very various structures can be seen. Some
portions, evidently andesitic, consist of perfectly idiomorphic
lath-shaped felspars scattered with a little decomposed hornblende
in a glassy brown ground mass. Others, more abundant, seem to be
altered quartz-diorite-porphyrite; in these parts, porphyritic quartz
and orthoclase crystals, in forms strongly inclined to idiomorphism,
clouded and strained, are scattered in a cryptocrystalline ground mass
containing a good deal of green chlorite and epidote. In other parts
of the slide, again, the chief porphyritic constituent is formed
by large green grains, which have evidently once been biotite or
hornblende, but which now consist of chlorite. In yet other parts of
the rock we have fragments of devitrified glassy lava. The different
parts, which are not always well outlined, are separated by schistose
bands composed mainly of strings of chlorite and epidote. Whether the
rock is a tuff, or a crushed conglomerate of igneous boulders and
pebbles, or due to complicated crushing of a series of contiguous
igneous rocks _in situ_, is not quite clear. In some places,
especially about the Wadi el Sheikh, the schists look like crushed
conglomerates, but these may possibly be rocks crushed _in situ_
rather than accumulations of rolled fragments transported by streams.
The hornblende-schists which surround Gebel Zergat Naam are of a
peculiar type of which the origin is not evident, but are possibly
altered andesites. The typical rock [11,526] is a hard grey basaltic
one of sp. gr. 2·95, with a rusty-brown skin on exposed surfaces. The
microscopic slide shows little plates and brushes of nearly colourless
hornblende, liberally scattered in a clouded ground mass consisting
mainly of hornblende fibres in radiating and dendritic groups, with
a small amount of kaolinic matter and a few grains of magnetite. The
slide contains no distinct quartz, but possibly a small amount of this
mineral may be present in very minute grains with the kaolinic matter.
To the metamorphism of andesitic lavas, too, are somewhat doubtfully
ascribed the grey and green schists of the Wadi Beida, which have
specific gravity of about 2·75. The slides from the grey variety
of the schists [12,116 and 12,159] show a very fine-grained clouded
rock, apparently a mosaic of quartz, kaolin, chlorite and sericite,
with larger scattered irregular plates of dark green chlorite. In
a pale green variety from the head of the wadi [12,111], there is
less chlorite and a considerable amount of calcite.
=Hornblende Schists of doubtful origin.=—In the more highly
foliated and harder varieties of hornblende schist, which are
typically of a darker colour than most of those already described,
we have rocks in which the process of re-crystallization has been
so complete that no trace of the original rock remains. These rocks,
which are true hornblende-schists in the narrowest sense of the term,
are less abundant than the foregoing types, and generally occur as
comparatively narrow bands associated with gneisses and mica and talc
schists. All the minerals in them being of secondary origin, they are
usually in a quite fresh state, and fractured surfaces, examined with
a lens, exhibit a mass of glistening small crystals of hornblende,
quartz, and felspar. The density is usually about 2·9. Microscopic
slides show elongated crystals of clear green hornblende, strongly
pleochroic (pale yellowish-green to deep blue-green) arranged along
the planes of schistosity, separated by clear granules of quartz
and a little felspar, with scattered magnetite grains.
[Illustration: Fig. 57.—Hornblende-schist, near Gebel Eqrun
[12,117], × 30. _h_, hornblende; _q_, quartz; _m_, magnetite. A
little felspar is present mixed with the quartz, from which it is
distinguishable only in polarised light.]
Near Gebel Eqrun are found hornblende-schists which exhibit a curious
banding in planes at right angles to the main foliation, in the form
of darker lenticular stripes a few millimetres wide and about the
same distance apart. A slide [12,117] cut from this variety shows
little trace of the banding, the lighter spaces between the dark
bands merely showing a clouding of the quartz and felspar by tiny
granules of epidote. The stripes are most probably the consequence of
a secondary compression in a direction perpendicular to the original
one rather than relics of a banded structure in the parent rock.
=Actinolite-schists.=—Very beautiful bright green schists, in which
the hornblende is in the fibrous to silky form called actinolite,
occur in small quantity associated with mica and talc schists at
Sikait [10,380] and elsewhere. In these rocks the actinolite fibres,
which often reach two centimetres in length, are generally aggregated
into bundles, with radiating structure. In the microscopic slide
the rock presents even a more beautiful appearance than in the mass,
the long fibres of actinolite polarising in the most brilliant tints;
associated with the actinolite, there is nearly always more or less
chlorite and talc.
=Hornfels.=
Associated with the schists of Gebel Abu Hamamid and the neighbouring
mountains there are great masses of very hard horny-looking rock
[10,401] of green to grey colour, breaking with a sub-conchoidal
fracture, and of such close texture as to appear homogeneous even
with a strong lens. The pyramidal peak called Gebel Um Semiuki, which
rises to 1,282 metres above sea, three kilometres to the north-east
of Gebel Abu Hamamid, is almost entirely composed of rocks of this
type; in the mountain faces the rock looks red, but this is only
due to a film covering weathered surfaces, the interior being of
a green to grey colour. The rock, which has a sp. gr. of 2·71, is
frequently beautifully banded, light and dark layers alternating with
each other, and often contains tiny cubes of pyrites [10,399]. The
microscopic slide from Gebel Um Semiuki shows a very fine-grained
clouded compact rock, apparently consisting of glassy matter with
minute granules of quartz and altered felspar, together with a little
sericite, the latter especially along certain bands. The slide from
Gebel Abu Hamamid is similar, but here the granules of quartz and
felspar are a little larger, though they are still too small to be
seen with a lens in the hand specimen; the appearance is that of
a quartz felsite on a small scale. It has already been mentioned
(p. 281) that the quartz felsites of Gebels Igli and Hadarba pass
gradually into hornfels, and when we remember that the schists of the
Abu Hamamid district are mostly crushed volcanic rocks, it becomes
almost certain that the hornfels associated with them is a crushed
and devitrified glassy lava of acid composition.
A yellowish horny rock with grey streaks [10,379], which occurs near
Gebel Sabahia, is conspicuous in the field owing to its weathered
surfaces being covered with a bright red ferruginous skin, resembling
cinnabar in colour. The sp. gr. is 2·52. Examination with a lens
shows the grey streaks to be filled with myriads of brilliant yellow
specks of pyrites. The microscopic slide shows these to be aggregates
of little cubes, while the bulk of the rock is a schistose felsitic
mass of quartz and felspar, with scattered larger felspar crystals,
much broken up and bent. In this rock too we have therefore a rolled
up and altered felsite.
=Mica-schists.=
Mica-schists, composed mainly of golden-brown lustrous laminæ
of biotite with more or less quartz, occur near the base of Gebel
Zabara and at Gebel Sikait [10,626], as well as in small quantity
at one or two other points. They are always associated with gneiss,
and appear to form irregular bands, alternating and mixed with talc
and other schists. The laminæ of mica can seldom be separated in
any large size, breaking up at a touch into small scales; they are
often highly contorted.
[Illustration: Fig. 58.—Beryl and quartz, from a lenticle in
mica-schist near Sikait [10,580], × 30. _b_, beryl in idiomorphic
hexagonal crystals; _q_, quartz, allotriomorphic.]
=Emeralds= (Beryl).—At Zabara and Sikait the mica-schists
contain crystals of beryl (silicate of beryllium and aluminium,
Be3Al2Si6O18), the clear variety of which forms the gem emerald. The
beryls are mostly found in lenticular bands of quartz which occur
in the mica-schist, but sometimes they can be seen in the schist
itself. The crystals are mostly well developed hexagonal prisms of a
pale emerald-green colour, with characteristic vertical striation. The
coloured figure on Plate XXV will give a good idea of the usual
appearance of the mineral. In microscopic slides (_see_ Fig. 58) the
beryls are conspicuous only by their clear cut hexagonal outlines;
they are quite colourless, with low polarisation colours about
the same as those of quartz. Both at Zabara and Sikait there are
numerous ruins and ancient mines where emeralds have been sought;
most of them are irregular shafts and tunnels, twisting about as
the old miners followed the varying directions of the bands of
schists. It is commonly believed that gem emeralds were at one time
extracted from these mines, and it seems incredible that the mining
should have been carried on to so great an extent as is shown by
the ruins and old workings, unless stones of considerable value were
obtained. The Zabara mines were re-opened by Cailliaud in the time of
Mohammad Ali Pasha (1817), but the stones extracted were of little
value, being clouded and full of flaws. A similar result followed
a more recent (1904-5) vigorous attempt by Mr. James, acting on
behalf of Mr. Edwin Streeter, of London, to work the emerald mines
of Sikait; plenty of beryls were found, but none clear enough to
be of any great value, and the enterprise was abandoned, Mr. James
concluding that either the ancient miners had worked out all the
bands containing stones of any value, or else, what is perhaps more
likely, the ancients were satisfied with a duller stone for a gem
than our modern jewellers. The dull forms of beryl are in our own
day of very little value, being principally used as a source for
beryllium salts in chemical laboratories.
[Illustration: Fig. 59.—Tourmaline crystals in graphitic
talc-schist, Sikait mines [9,908], × 17. _t_, tourmaline crystals,
irregularly cracked and clouded; _g_, talc-schist, heavily clouded
by graphite.]
=Tourmaline.=—Besides beryls, the mica and talc schists of Sikait
contain in places abundance of black tourmaline in well-developed
crystals. At some spots this mineral is so plentiful as to form
practically small patches of tourmaline-rock [10,395]. In thin section
[9,874 and 9,908] the tourmaline crystals, which are much clouded
and irregularly cracked, show beautiful pleochroism (colourless to
deep orange), and very high double refraction colours in prismatic
sections. Like the beryl, however, tourmaline is only of value as
a gem when it is clear and transparent, and all the crystals so far
obtained are dull and opaque.
Calcite, in rhomb-shaped crystals of a brown colour due to presence
of included iron oxides [10,382] likewise occurs in places in the
mica-schists of Sikait.
=Chlorite-schists.=
Though many of the decomposed hornblende-schists contain more or
less chlorite, I have only in two localities come across rocks
_in situ_ which contain so large a proportion of this mineral as
to deserve the name of chlorite-schists. The first is in the hills
of Um el Huetat (latitude 25°), where typical chlorite-schists are
mixed with mica, talc, and hornblende schists. The second locality
is between Gebels Ras Shait and Nugrus, where the rock [10,388]
is remarkable not only in its peculiar appearance but also by its
strongly magnetic character. It is a thoroughly schistose rock of
a rather pale greyish-green colour and rather silky appearance,
with rusty looking spots. The sp. gr. is 2·77. The microscopic
slide shows the stone to consist essentially of an aggregate of
elongated plates and fibres of low double refraction, which from the
hand specimen seem to be chlorite, but in the slide look more like
antigorite. Magnetite grains are liberally scattered through the
chloritic mass. The rusty spots visible in the hand specimen are
translucent foxy red in the slide, in irregular broken forms with
well-marked cleavage and nearly straight extinction. They are somewhat
doubtfully regarded as deeply iron-stained hornblende. Mixed with the
foxy red material are aggregates of granules of a highly refracting
but isotropic mineral of deep bottle-green colour (? spinel),
and chloritic wisps. There are also some clear colourless grains,
resembling apatite in appearance except that they sometimes show
well-marked vertical cleavage and high extinction angles; these are
possibly a colourless augite, but the double-refraction colours are
far lower than is usual with this mineral.
Typical chlorite-schists occur in the Wadi Salib Abiad, and near
Gebels Ribdab and Muqsim, in the extreme south-west portion of the
region. Hearing, from some wandering Arabs while at Gebel Abu Dahr in
February 1907, that prospectors were at work in the Wadi Salib Abiad,
I sent a guide to find out who they were and what they were doing;
the guide reported that on his arrival they had gone away, but there
were some old workings in a green rock of which he brought a sample. I
did not get an opportunity of visiting the locality personally,
but the specimen brought back by the guide [11,523] is a beautiful
apple-green chlorite-schist, with some brownish calcareous-looking
bands. The microscopic slide shows some little quartz and talc besides
the chlorite, and there are scattered minute highly-refracting rounded
grains of a feebly translucent mineral of a reddish-brown colour,
probably rutile. A similar rock from the eastern side of Gebel Muqsim
has been reported by Mr. Charteris Stewart, who also records a normal
chlorite-schist as occurring on the north side of Gebel Ribdab.
=Talc-schists.=
Talc-schists, though not widely distributed, are abundant in certain
localities. They form the main rock in many of the hills in the
district called Um el Huetat, to the west of Gebel Atut in latitude
25°, where there are numerous old mines. In this district there are
immense masses of talc-schist of remarkable purity. The rock [10,364]
is of a grey to green or brown colour, distinctly schistose, cleaving
easily with a soapy feel, and easily scratched by the finger nail;
more massive forms occur which can be easily carved into pipes, and
these are frequently smoked by the Bedouin. I descended one of the old
shafts at Um el Huetat, and found no evidence of other minerals having
been worked than the talc itself. A somewhat more earthy variety of
talc-schist [10,396] was met with near the Rod el Ligaia. Talc-schists
also occur at Gebel Sikait [10,383] and Gebel Zabara, where, as at
Um el Huetat, they alternate with mica and hornblende schists. But
at Sikait and Zabara the talc-schists are decidedly subordinate to
the mica-schist in which the beryls are found.
To the class of talc-schists is also probably best referred a fissile
and very rotten purple-brown schist, containing cubes of limonite,
which was found near the triangulation station on Gebel Hamida,
and again near the old mines of Romit. The microscopic slide of
the Romit specimen [12,139] shows the bulk of the rock to consist
of talc and chlorite, with blotchy stains and floculent-looking
masses of brown iron oxide and occasional clear irregular granules
of quartz. In this are plentifully embedded perfect little cubes of
limonite. The limonite cubes [12,129 and 12,136] weather out easily
from the rotten matrix, and can be gathered from the ground at the
foot of the exposed surfaces.
=Calcareous Schists and Marble.=
Some very curious calcareous schists are found in Gebel el Anbat and
its neighbourhood, near the Wadi Hodein. In Gebel el Anbat itself a
mass of these rocks rises to a height of over 250 metres above the
wadi level. They are earthy-looking rocks of varying colour, chiefly
brown and reddish, often purplish on the rough weathered surfaces,
and sometimes have a talcose feel. A typical specimen [11,532 A]
has a sp. gr. of 2·92, and the slide cut from it shows it to be
almost entirely composed of grains of calcite, with here and there
larger irregular granules of quartz and of what looks like altered
felspar, and a liberal sprinkling of iron oxide. It is difficult to
assign an origin to this rock, but a variation of it [11,532 B] has
been already described (p. 339) as probably an altered syenite, and
the main rock may therefore represent the extreme form of alteration
of an igneous rock rich in lime felspars.
A hard close-grained reddish-brown rock of sp. gr. 2·91, with dark
streaks [12,107], which forms a high ridge, swathed in blown sand,
rising to 350 metres above sea-level near the Wadi Kreiga, eleven
and a half kilometres to the south-east of Gebel Beida, resembles a
quartzite in appearance, but turns out on careful examination to be a
calcareous schist. The microscopic section shows a very fine-grained
mosaic of calcite with a little quartz, and scattered grains and
strings of iron oxide. The origin of this rock is uncertain; it may
be a metamorphosed limestone.
The summit of a high hill rising to 686 metres above sea, on the
east side of the Wadi Um Khariga in latitude 24° 56′ 30″, is
a gozzany mass resembling the outcrop of a mineral vein traversing
the schists. On a fresh fracture, the interior of the rock [10,369]
is seen to consist mainly of dark crystalline calcite, with some
cubical crystals of pyrites, numerous rusty looking spots and patches
of limonite, and veinlets of white calcite. The microscopic slide
shows a mixture of calcite with kaolinic and serpentinous matter,
with a very pronounced schistose structure, containing “eyes”
of mixed calcite and iron oxides; the rock is therefore in reality a
ferruginous calcareous schist. The mass is too highly metamorphosed
for more than a guess as to its origin; but the slide contains some
granules resembling picotite and one or two small patches of what
looks like altering felspar, and the suggestion is that the schist
is a metamorphosed basic igneous vein.
=White crystalline marble= has been found only at one point, namely,
about three kilometres south of the jagged peak called Qash Amir,
west of Gebel Elba, where it forms a small patch in crystalline rocks.
=Graphite-schists.=
A considerable mass of graphite-schist occurs associated with diorite
rocks near some ancient gold workings at Gebel Allawi. The extent of
the graphite-schist has not been mapped, but it occurs on the north
slope of the mountain, and as seen from the summit it appears to run
out westward for miles as a broad black band. The rock [10,378],
which has a sp. gr. of 2·70, consists of a mixture of graphite
with calcareous and earthy matter. The parts richest in graphite are
readily cut with a knife, and mark paper easily. Analysis shows that
the graphite, though sufficiently abundant to appear in the hand
specimen the dominant mineral of the rock, is nevertheless present
in surprisingly small proportion; a sample tested by Mr. Pollard
was found to contain only a trifle over one per cent. of carbon.
A similar graphite-schist occurs associated with mica-schist in
one of the emerald mines of Gebel Sikait, and it may be remarked
that graphitic schists have also been observed by Dr. Hume near
the lodes in the gold mines of Baramia and Um Garaiart, both of
which localities, however, lie outside the limits of the area here
described.
The origin of the graphite-schists is uncertain. Perhaps the
hypothesis presenting the least difficulty is that which supposes
them to have been formed from ancient sedimentary rocks containing
the remains of plants; on this view the close association of dioritic
rocks suggests that the great of igneous intrusion may have played a
part in the distillation of the more volatile matters of the plant
remains, while the schistose structure shows that pressure has
also been active in the formation of the rock. But the absence of
any associated rocks which bear distinct signs of having originally
been ancient sediments makes one hesitate to refer the graphite to
an organic origin, and possibly the carbonaceous matter may have
been produced from quite another source than that of plant life.
=Breccias.=
A very curious rock [10,385] which from a distance looks like a giant
diorite, occurs as a band in gneiss on the west side of the lower
part of Wadi Nugrus, is doubtless a fluidal breccia. It contains
ovoid masses of white aplite, sometimes measuring five centimetres
in diameter, embedded in a dark fine-grained dioritic matrix with
a marked tendency to schistose structure. Most likely the rock has
been formed by the catching up of the fragments of a crushed aplite
in an intrusive diorite, and then the whole mass has been subjected
to the same pressure which foliated the surrounding gneisses.
More normal breccias are found at various points. One which occurs
between schists and hornfels near the summit of Gebel Abu Hamamid
[10,398] is made up of fragments of various altered volcanic rocks,
with large black flint-like lumps of hornfels, all cemented into a
very hard rock which breaks across the fragments composing it. This
breccia was doubtless formed by the same movements which produced the
schists of the summit of the mountain; these latter (_see_ p. 341)
are themselves almost as much fine breccias as schists.
To the west of Gebel Zergat Naam the stones in the wadis are sometimes
cemented into hard breccias by calcareous matter, doubtless deposited
by drainage waters which have dissolved out the lime from felspathic
rocks.
In the hill called Ti Keferiai, a little below the triangulation
point which marks the summit, a highly altered fine-grained dioritic
rock, containing much epidote, has been crushed into a coarse breccia
[12,123] cemented by rose-coloured quartz.
A remarkable green breccia is found in Gebel Hamata, where it appears
to form a large mass in the mountain-side to the east of the main
peak. This rock [10,407], which has a sp. gr. of 2·92, is darker
in colour and somewhat softer than the ornamental “breccia verde
antico” of the Wadi Hammamat district further north,[135] but it
also is a very beautiful rock. In the hand specimen, it consists of
black angular fragments, up to two centimetres in diameter, embedded
in a dark green ground mass, the whole of very fine grain and barely
scratchable with a knife. Under the microscope, the black fragments
seem to be of basaltic nature, while the green matrix is probably a
highly crushed and brecciated diorite-porphyrite; the whole of the
slide is clouded by decomposition products.
=Fault-breccias=, produced by differential movement of the two sides
of faults, occur in the neighbourhood of the Wadi Saalek, where the
sandstones and schists are much faulted (_see_ p. 359). The breccias
here [11,539] are narrow bands which stand up like dykes; they are
very calcareous and highly ferruginous, with occasional green stains,
perhaps due to traces of copper.
=Mineral Veins.=
Quartz veins deposited by solutions[136] in cracks and fissures
of the igneous and metamorphic rocks are very numerous and widely
distributed, especially in the Sukari district. They vary immensely in
size, from mere strings to veins two metres or more in thickness; they
cut the rocks in every direction and at every angle of dip. Steeply
inclined veins are by far the most numerous, but some have a flat
inclination and are then styled “reefs” by the miners.
The principal interest attaching to the quartz veins is the fact that
they frequently contain gold, though seldom in particles visible
to the unaided eye. The quartz veins were worked for their gold by
the ancients, the remains of whose dwellings and stone grinding pans
are found at numerous places, as for instance in the Wadi Hangalia,
at Kurdeman, near Gebel Sabahia, at Gebels Sukari and Allawi, in
the Wadi Lewewi, and at Romit and Darahib. Our modern prospectors
have found these ruins of ancient mining camps and grinding pans
to be the best guide to auriferous veins, gold being seldom found
except in and near the old workings. As mentioned on p. 27, the
ancients worked the mines by convict labour, and they could for
that reason afford to work ores which are too poor to pay under
modern conditions. But in certain cases the veins have been found
rich enough to give possibilities of a commercial return to modern
mining enterprise; a list of the prospecting licences and mining
leases now in force is given on p. 28. As to the source of the gold,
it is not known whether it came up in solutions from below, or has
been secreted laterally from the country rock.
Besides gold, some of the quartz veins contain traces of copper,
but none of the occurrences of copper ore within the area specially
treated of in this book appear to be capable of yielding any
considerable quantity of the metal, most of them in fact being
mere stains due to oxidation and carbonatisation of traces of
sulphides.[137]
Calcite veins are much more rarely met with than those of quartz. In
only one of the veins I have examined is calcite present in any
considerable quantity, namely in the vein of the old gold mines of
Romit. In this vein, white to brown crystalline calcite is found
mixed with chalybite, limonite, and smoky quartz [12,105 and 12,141],
the last-named only being apparently auriferous. There did not
appear to be enough chalybite and limonite in the vein to make it
worth following up for iron ore, especially in view of the expense
of transport from the place.
Magnesite and asbestos veins occur in the serpentines of the Gebel
Gerf district. These occurrences, which appear not to be large enough
to be worth working, have been described on p. 330.
* * * * *
[Footnote 134: The figures in square brackets in this and the
preceding chapter are the numbers under which the specimens are
registered in the Geological Museum, Cairo.]
[Footnote 135: _See_ Barron and Hume’s “Eastern Desert.” Cairo,
1902. p. 263.]
[Footnote 136: Other quartz veins which probably originated in quite
a different manner are treated of under the heading of Igneous Rocks
_see_ (p. 266).]
[Footnote 137: The copper smelted in ancient times at Kubban, on
the east bank of the Nile opposite Dakka, in latitude 23° 10′,
was possibly obtained from mines at Abu Seyal (sometimes misspelt
Absciel), north of the Wadi Alaqi in latitude 22° 47′, longitude
33° 44′, where there are extensive old workings, Abu Seyal lies
outside the region described in this volume; a reference to the
mines will be found in the _Report of the Egyptian Department of
Mines for 1906_, p. 34.]
CHAPTER XI.
* * * * *
=TECTONICS AND GENERAL GEOLOGY.=
* * * * *
=Evidence of a former Pluvial Period.=
Given a sufficiently long period for their activity, the denuding
and transporting agencies at work at the present day are capable of
accounting for most of the superficial sculpturing of South-Eastern
Egypt. The country is not absolutely rainless, and within a decade
most of the dry valleys have been for a few hours the beds of
streams, the result of rain storms. There is practically no frost
in this part of the world, so that disintegration by the freezing
of water in crevices of the rock does not occur on any large scale;
the diurnal variations of temperature, are, however, so great that
this cause alone is very potent in breaking up rock material. The
disintegrated matter accumulates as heaps of debris and sand, ready
to be transported towards the Nile or the sea by the streams which
follow the next rainfall. Both in erosion and in the transport of
sand, wind is a very active agent, and accounts for the formation and
distribution of immense quantities of sand. Thus the mountains are
slowly being lowered, and the rocky valleys between them are being
widened and deepened, even at the present day, and the accumulations
of sand on the coast-plain and elsewhere are being slowly increased
in thickness.
But when we look at the great wadis, often hundreds of kilometres
in length, cut to a depth of fifty metres with a width of half a
kilometre through the sandstone plateaux which separate the mountain
ranges from the Nile, it is difficult to conceive that rainfall and
denudation have not in the past been greater than at present. In
our own day, it is but seldom that the great wadis convey streams
as far as the Nile or the sea, their waters being usually absorbed
by the sandy bed before the end is reached; erosion nowadays is
practically confined to the upper reaches of the wadis, and unless we
postulate greater rainfall in the past, inconceivable ages must have
been occupied in the erosion of these great channels. We are thus
driven to believe that what is now a very dry area was formerly one
of considerable rainfall. This belief is supported by the traces of
glaciation in Europe, for it is natural to infer that when temperate
Europe had an arctic climate, northern Africa had a temperate one;
the effect, whatever its cause, being practically equivalent to an
increase of latitude. This change of climate is equally evidenced by
geological observation in other parts of Egypt. It is even likely
that the climate of Egypt may be slowly changing at present; but
the change within the historical period has been so small as to be
practically negligible.
=Origin of the Red Sea.=
If the 200-metre contour of the bottom of the Red Sea, shown on Plate
I, be examined, it will be found to exhibit great indentations
towards the great mountain masses, while there is a curious
projection including the Island of Zeberged which mimics the present
Ras Benas. Some of the indentations of the contour line lie in the
direct prolongation of existing great wadis, such as those of Lahami,
Khoda, Hodein, Di-ib, and Serimtai. The obvious suggestion from this
coincidence is that the sea has encroached on the land since the
drainage-system had substantially its present form, and we infer a
sinking of the region at no very remote geological epoch. The central
parts of the Red Sea attain depths of over 2,000 metres; thus this sea
was a great and deep one even when the level of its waters, relative
to the land, was 200 metres lower than now. We have no information
which would give us a clue to the origin of this primitive sea, but
the inference from the contours is that the _present_ extent of the
Red Sea has been caused by a great general subsidence of the land,
and not by trough-faulting as has hitherto been usually stated.[138]
The subsidence just referred to was even greater than would be
gathered from a consideration of the present coast-line. At intervals
along the entire eastern coast of Egypt are hills of gypsum;
these are never found except close to the present sea-borders,
and the natural deduction is that the gypsum beds were deposited
when the sea was at a higher level than at present. At Ras Benas,
the gypseous strata reach altitudes of nearly 200 metres, so that at
the time when the gypsum was formed the Red Sea must have covered a
much greater area than now, extending in fact approximately to the
contour of 200 metres above present sea-level. As to the epoch when
this greater extent of the sea existed, we should have a clue if we
knew the age of the gypsum beds, which unfortunately is not the case;
but they are almost certainly younger Tertiary beds, possibly Miocene
or even Pliocene, so that in any case the Red Sea is a depression
of considerable antiquity.
=Possible Former Extent of the Eocene Rocks.=
Eocene rocks are entirely absent from the district, and the same is
the case with Cretaceous rocks younger than the Nubian sandstone. But
if we go westward along the parallel of Berenice, across the Nile
into longitude 23° 30′, we come to the plateau face of Gebel Garra,
where there are exposed thicknesses of about ninety metres of Eocene
limestone and 240 metres of Cretaceous marls. These beds cover great
expanses further west and north; they evidently once extended beyond
their present limits, and we may ask whether they ever reached over
the Red Sea mountains here, as is the case in North-Eastern Egypt. To
this question no answer can be given; from Berenice to Gebel Garra is
a distance of over 300 kilometres, and even a very gradual thinning
of the beds eastward would account for their absence from the main
mountains; at the same time the denudation which has removed every
trace of the hard Eocene limestone from the plain between Gebel
Garra and the Nile may well have done the same further east.
=Original Extent of the Nubian Sandstone.=
The Nubian sandstone is found on both sides of the watershed ranges,
and the question raised by its distribution is in regard to its
possible original continuity. Did the Nubian sandstone once extend
over the present igneous mountains, or was it laid down on either side
of a great island ridge? In other words, did the Red Sea mountains
exist as such in Cretaceous times, or have they been subsequently
elevated, and the Nubian sandstones which covered them denuded
away? To this question it may be stated at once that no certain
answer can be given; but a good deal of study has been devoted to
the facts bearing upon it, and these facts will be briefly enumerated
and discussed below.
_Evidence from Volcanic Intrusions._—That the Nubian sandstone
is younger than the igneous rocks in general is proved by the
almost complete absence of intrusions into the sandstone. Apart
from an interbedded diabase sheet in the north part of the region
and a small basic dyke near Gebel Awamtib, the igneous rocks appear
nowhere to penetrate the Nubian beds. The sandstone is _a fortiori_
younger than the metamorphic rocks into which the igneous masses
have been intruded.
_Evidence from Present Distribution._—Coming now to the distribution
of the sandstone, though we find it on both sides of the main ranges,
there is not a trace of sandstone among the higher mountains; this
of course proves nothing, for denudation would be most active among
the peaks and in districts of maximum up-thrust, and sandstone
is an easily erodible rock. The long tongue of sandstone plateau
which terminates in Gebel Anfeib extends indeed right across the
main watershed, but a reference to the orographical map (Plate I)
will show that this extension is along a north-west to south-east
general depression, where the Wadis Hodein and Garara form a cut
across the map separating the main mountain masses into north and
south groups. The presence of the sandstone tongue here would be
equally well accounted for whether the mountains were elevated before
or after the deposition of the Nubian beds.
Not only is the sandstone absent from the main mountains, but
it is never found in such close proximity to them as to render
a decisive answer to our question. Thus the eastern scarp of the
sandstone plateau in the north part of the area overlooks a broad
tract of low country between it and the mountains; and similarly
from Gebel Anfeib one overlooks low country to the north, east, and
south. On the eastern side of the mountains the sandstone deposits
are restricted to small patches considerably removed from the main
summits, and even in most cases from their foot-hills.
_Evidences from Structural Features._—With regard to the structural
evidences to be gathered from the sandstone itself, it was hoped
that the observations of the dip of the beds at different places
would throw light on the question as to whether their deposition
antedated the mountain formation or no.
To the north of latitude 24°, the eastern edge of the sandstone
scarp showed beds differing but little from the horizontal, though
very gentle folding in various directions is probable.
Further south, near Gebel Zergat Naam, much more decided evidences
of folding, and even of dislocation, were met with. The head of the
Wadi el Kreim, south-west of Zergat Naam (_see_ the geological map on
Plate XX) is probably a line of fault, for here on the south-west of
the wadi we have sandstones coming right down to the wadi floor, with
a dip of 30° to the south-west near the edge, becoming flatter the
further we go from the wadi, while on the other side are crushed and
brecciated schists. Going further west, in the sandstone hill-mass
which lies twelve kilometres west of Zergat Naam, the dip of the
beds is in the opposite direction, being 10° to 15° north-east,
and granite appears at the foot of the steep west-south-west slope;
this, with the preceding observation, seems to indicate a synclinal
fold terminated near Zergat Naam by a fault up-thrusting the schists
and syenite.
Where the Wadi Garara cuts through the sandstone hills to receive
the Wadi el Kreim, the beds dip markedly to the south, the observed
inclinations being 60° or more at the north edges, rapidly falling
to 20° or less further south; the north faces show granite and
schists at their base.
Further west, on the way to Gebel Um Harba, the sandstone of the
hills showed dips to the east of 15°. At Gebel Um Harba itself there
are thick beds of sandstone dipping 13° east-north-east, while all
around the mountain one looks out over beds having approximately
the same inclination.
At Gebel Um Khafur, the dip is 13° to 14° to the north-north-east,
and is very constant over a large area. From the north side,
where the plain is 380 metres above sea-level, the hills rise
with a succession of dip slopes and basset-edges over a horizontal
distance of 2·9 kilometres (measured perpendicular to the strike)
to the triangulation beacon at 560 metres above sea, the beds all
along dipping at 13° or 14°. Unless there is step-faulting here
along the strike-wadis (_see_ Fig. 60) the total thickness of Nubian
sandstone here is over 450 metres. This is a much greater thickness
than has been noted anywhere else in Egypt, and I am inclined to
think that there is step-faulting along at least two of the strike
wadis which separate the hill-mass into ridges.
[Illustration: Fig. 60.—Section of Sandstone at Gebel Um Khafur.]
In approaching Gebel Awamtib from the north-west, I crossed over a
small patch of diorite in the sandstone at the pass from Wadi Um
Terbi into Wadi Awamtib, and a basic dyke was found cutting the
sandstone of a spur of Gebel Awamtib. The beds of Awamtib itself
dip pretty uniformly a little north of west.
[Illustration: Fig. 61.—Sketch section of junction of sandstone
with granite, west of Gebel Um Keit.]
About nine kilometres to the south of Gebel Awamtib, a station was
taken on a sandstone headland with schists and quartz veins at its
floor, and afterwards I skirted the limit between sandstone and
granitic rocks on the way to Gebel Um Reit. All along this route
there was no suggestion of sharp folding or faulting; the beds were
nearly horizontal right up to the limit, where the granite hills
rise suddenly (_see_ Fig. 61).
From the top of Gebel Um Reit, which itself is granite, the sandstone
limit could be seen to the north and east; the beds dip 30° in
places; in those on the east the direction of dip is about south. The
region round Um Reit is evidently one of considerable disturbance,
but the sandstone is too far off for one to get any precise idea of
its nature from the summit.
[Illustration: Fig. 62.—Sketch of faulting near Wadi Saalek.]
Going northwards from Um Reit across the Wadi Saalek and up one
of its branches into the head of Wadi Muegil, there is a good
exposure of faulted sandstone overlying schists just before reaching
the pass. Here (_see_ Fig. 62) one of the faults is a distinct
overthrust, with a north-easterly strike, and there are other faults
in a parallel direction.
From the Wadi Muegil northwards past the Galt el Aguz to Gebel Um
Harba there are gentle dips and curvings of the sandstone beds,
with a predominant dip about north-east. At the Galt el Aguz the
sandstone rocks are much tumbled about, but this appears to be due
to fall of over-hanging beds.
At the pass from Wadi Um Arta into the head of Wadi Silsila,
the dip of the sandstone is north-north-east. In its lower part,
Wadi Silsila passes between sandstone ridges the dip of which is
constantly east-north-east.
Round Bir Abraq and the triangulation station on Gebel Abraq
(_see_ large scale map on Plate XV) the main direction of dip is
east-south-east; the pool of Bir Abraq itself is under projecting
slabs of sandstone dipping in this direction. Bir el Sunta, a little
further north, appears to lie in a syncline, the beds of the hills to
the north dipping south-east, while those to the south dip north-west.
Approaching the sandstone from the east by Wadi Hodein, one traverses
granite country with felsite dykes and enters suddenly into high
sandstone plateaux. The beds at the Abu Saafa Springs dip about
5° northwards.
The beds of Gebel Dif and Gebel Anfeib have a prevalent dip on the
west side to the east and north-east, while on the east face the dip
appears to be in the reverse direction. This great mass of sandstone
plateau may thus be a syncline with a north-westerly strike (_i.e._,
a strike roughly parallel to the main direction of the watershed
mountain ranges), but the eastern face was not examined in detail,
and it may be that the whole mass dips to the north-east; some
outlying small sandstone masses near the head of Wadi Edunqul show
no reversal, the dip being still east-north-east. At Bir Dif the
sandstones are variously tilted, and probably faulted.
The sandstones on the east side of the watershed ranges, near Gebel
Ranga, were observed by Dr. Hume to dip towards the sea. In the south
part of the region there are some low hills forming two series of
ridges between the sea and Gebel Kolaiqo, separated by hills of red
aplitic granite; these hills were not actually visited, but were
mapped from some little distance, and the dip of the beds was not
measured, but the nature of the rocks was confirmed by specimens of
sandstone brought back by guides sent to the place.
Summing up the dips and disturbances of the sandstone beds at the
different places, it is clear that the strata are the more disturbed,
the more closely they approach the main mountain ranges; this and
the seaward dip of the beds near El Ranga are so far in favour of
the view that the sandstone may once have extended right over the
present mountains. But it will be seen that the disturbances of
bedding are of an irregular character, especially between Gebels
Zergat Naam and Um Reit, where the folding and faulting are often
in directions quite distinct from that of the main mountain axes,
and it may be that these disturbances are due to later movements
rather than to the elevation of the main mountain ranges. So far as
observations on the sandstone itself go, therefore, the question as
to whether the Nubian sandstones of the Red Sea border ever directly
joined those on the west of the mountains remains open; the observed
disturbances of the beds give us clear proof that considerable earth
movements have taken place since the sandstone was deposited, but
they are inconclusive as to whether these same movements caused the
elevation of the great mountain ranges.
=The Igneous and Metamorphic Rocks.=
Turning now to the main mountain-forming rocks, we find them composed
of the two great classes, igneous and metamorphic. Though in places
we have transition members, such as granites passing into gneiss, yet
on the whole the two groups are quite distinct, and we find typical
igneous masses rising in the midst of equally typical schists. Under
these circumstances there can be no hesitation in considering the
two groups to be of different ages, and that the igneous rocks must
be the younger.
The igneous masses are divisible geologically into the three classes
of (_a_) lavas, (_b_) dykes, and (_c_) plutonic rocks.
_Lavas._—Amongst the igneous rocks, the lavas are those most
poorly represented. Apart from the andesite of Gebel Sufra, and the
diabase sheets in or under the Nubian sandstone, there are only a
few occurrences of volcanic rocks in all the area, a circumstance
which is easily explained by the enormous denudation which has
gone on and the fact that lavas, being superficial out-pourings,
will have been most exposed to denuding forces.
_Dykes._—Dykes seam the schists and igneous rocks, frequently in
such numbers and with such parallelism as to give to the land the
form of a succession of ridges separated by long narrow depressions,
forming “dyke country.” In nature, the dykes vary from extremely
acid rocks like aplites and quartz-felsites, to very basic forms
such as diabase and basalt. There is on the whole a preponderance
of basic over acid types. As already remarked, only one instance
of a dyke cutting the Nubian sandstone has been observed in the
district. Another significant feature in the distribution of dykes
is that while dykes of all kinds are found cutting schists and acid
plutonic igneous rocks, the basic plutonic masses are as a rule free
from dykes; this suggests that the basic plutonic rocks may be on
the whole younger than the acid forms.
_Plutonic Rocks._—The plutonic rocks include granites, syenites,
diorites, gabbros, pyroxenites, amphibolites, and peridotites. But
these are not all of equal importance, and a natural division from the
field observations is a two-fold one into acid and basic groups, which
are tolerably well marked off from each other and are most likely of
different ages. The acid class on this view consists of the granites
and syenites, while the basic class contains all the other rocks
above-mentioned. The granites are on the whole of a very acid type;
syenite is very scarce and nearly always occurs in close association
with granite. Of the basic group, probably the most abundant and
most typical rock is gabbro; diorites and the various ultra-basic
rocks are almost always closely associated with gabbro. Where acid
and basic rocks occur in proximity (as for instance near Bir Abraq,
where an acid granite occurs side by side with a serpentine) there
is a sharp change, without transitional forms.
The much greater abundance of dykes in the plutonic rocks of the acid
group as compared with those of basic composition, as mentioned above,
inclines us to regard the basic group as the younger—a view which
is further supported by the greater frequency with which a tendency
to gneissose structure is noticeable in the acid rocks. The fact that
the basic members are frequently in a higher state of decomposition
than the acid ones is not contrary to this view, being due to the
greater ease with which their constituents undergo weathering; and
as explained on p. 315, the fissured state of the altered peridotes
is probably not due to the same earth forces which have sheared the
granites, but to internal stresses set up by the expansion of the
rocks on serpentinisation.
Though we may be fairly sure that the basic plutonic rocks are
on the whole younger than the acid ones, we have no certain guide
from which to estimate the geological age of either. We know from
their relations to the sandstone that they are both older than the
Upper Cretaceous, but we cannot say how much older; they may be
anything from Archæan to Jurassic; the circumstance that similar
rocks underlie Carboniferous strata in Sinai inclines us to place
them at least as far back as Palæozoic times.
_Gneisses and Schists._—The gneisses and schists which cover so much
of the country are obviously older than the plutonic masses which
are intruded in them, and for these metamorphic masses we need have
small hesitation in speculating on an Archæan age. They exhibit a
wonderful variety of composition. Most of the gneisses are doubtless
sheared ancient igneous rocks, such as granite and diorite, and a
similar origin may be assigned to many of the schists. Other rocks,
as for instance the clay-schists, graphite-schists, and marble,
have almost certainly originated from the metamorphism of ancient
sedimentary rocks. But in a large number of cases we have at present
no clue to the parent rock from which the schists have been formed.
=Summary of Geological History of South-Eastern Egypt.=
Having in the foregoing pages discussed the evidences for the relative
ages of the different classes of rocks and their mutual relations,
we may now endeavour to reconstruct the past geological history of
this part of Egypt from the information gathered. In this process
we shall reverse the order of consideration taken above, and begin
with the oldest rocks.
The schists and gneisses probably represent, not the original crust
of consolidation of the earth, but a complex of ancient sedimentary
and igneous rocks, laid down in pre-Palæozoic times and subsequently
crushed, folded, and faulted into mountains which were subsequently
denuded and worn down. In parts of the main mountain-masses we may
possibly still have the cores of some of these ancient elevations,
but most of the present mountain peaks are formed of a later series
of igneous rocks.
The first igneous intrusions into the schists and gneisses were
the granites which form such peaks as Gebels Nugrus, Faraid, and
Elba. Then followed crushing and folding of these rocks, giving
them often a gneissose structure and opening fissures, up which came
later intrusions, mostly of basic rocks, in the form of dykes. With
the dykes or later came great basic intrusions of gabbroid rocks,
forming such masses as Gebels Dahanib, Gerf, and Meisah.
A long interval now followed of which the rocks contain no record. We
do not know whether the area was submerged or not in Palæozoic and
early Mesozoic times; but if it was, all trace of the deposits of
these ages has vanished in the great denudation which surely took
place before the Upper Cretaceous sea swept over the country and
deposited the Nubian sandstone. We do not know whether the Red Sea
mountains then stood up as islands, or whether they were subsequently
elevated. Nor do we know whether the area remained wholly or partly
submerged during the Eocene period. But we are sure that at some time
between the Upper Cretaceous and Oligocene epochs there was a great
elevation of the land, with folding and faulting, especially in the
areas now occupied by the great mountain masses, and possibly the
mountains had their origin in this movement of elevation. The Red
Sea depression may well have originated in a complementary sinking
at this same period. The depth of the sea is of the same order
(2,000 metres) as the height of the mountains on the adjacent land.
In the succeeding Oligocene period the land was being sculptured
into something like its present form, and probably the main drainage
lines of to-day were then formed.
About the Miocene epoch there was a sinking of the crust in this
region. The Red Sea increased in area, and then, probably as the
results of evaporation in a closed sea, deposits of gypsum were
laid down. A subsequent elevation in Pliocene or post-Pliocene times
raised these deposits along the present shores.
In geologically recent times a further gentle elevation has gone on,
giving rise to slightly raised coral-reefs and sea-beaches. During
the glacial period of Europe, the rainfall in Egypt was probably
greater than at present, and during this period the great wadis
received almost their final sculpturing. After the change from this
rainy climate to the dry one of to-day, erosion still went on, though
more slowly, in the hills; but on the plains and along the coast
accumulation of sands took place, partly owing to wind transport,
and partly owing to the insufficiency of the drainage waters to carry
their load as far as the Nile or sea. The abundance of coral-reefs in
the Red Sea is largely conditioned by the lack of in-flowing streams
of silt-laden water; for the coral animal flourishes only where the
water is clear.
* * * * *
[Footnote 138: SUESS, in _The Face of the Earth_ (English edition,
Vol. I, p. 374), states that “the Red Sea itself is, however,
a trough-subsidence, probably the greatest in the world.”]
CHAPTER XII.
* * * * *
=TRIBAL BOUNDARIES.=
* * * * *
The Bedouin tribes[139] inhabiting South-Eastern Egypt are:—
_North of the administrative boundary_ (Ababda tribes):—
Ashabab.
Meleikab.
_South of the administrative boundary_ (Um Ali Bisharin tribes):—
Hamedorab
{ Kurbeilab
{
Aliab { Balgab
{ { Koatil
{ {
{ Sarrarab { Mallak[140]
{
{ Mohammad Omerab[140]
I had hoped, in surveying the country, to be able to place the
boundaries of the territories of the different tribes on the field
maps, and with this object in view I ascertained the claims of
each tribe as precisely as possible from representative men of the
different tribes who accompanied me over the ground.[141] I found that
in several places the tribal claims overlapped, and in consequence I
have not inserted the boundaries on the general maps. But I was able
to obtain a clear and definite idea of the various claims made at the
time, and as this information was obtained on the actual ground, I
propose to set it down here as being a useful basis for consideration
if ever it is necessary to decide upon the question of rival claims.
On the small scale map[142] which forms Plate XXVI, I have shown
the various claims as accurately as the scale will admit of, and a
reference to it will enable the statements of claim to be generally
followed; but as the disputed portions frequently concern somewhat
small wadis, it will in some cases be better to refer to the larger
scale maps on Plates XV, XVII, and XVIII, to follow the smaller
details.
I would remark that there did not appear to be anything in the nature
of a quarrel between the various tribes over the areas of disputed
ownership, these areas being occupied indifferently by either tribe,
or by men of both tribes living amicably together. It was only when
I attempted to lay down on a map the precise boundary of each tribe
that I found certain areas had two or more claimants. In the country
south of the administrative frontier, the wells and vegetation are
sufficiently abundant, in proportion to the population, for the
question of ownership never to be a matter of heated controversy
in ordinary years; and I am told that the present relationships of
the tribes are so friendly that although each tribe would resent any
statement as to ownership of its traditional grounds by the others,
yet as a matter of fact no objection is raised to camels and sheep of
one tribe grazing in the grounds of another, a give-and-take policy
being usual. When I was at Halaib, Sheikh Batran Ali Tiut (of the
Hamedorab) told me they never had disputes about grazing rights, as
there was plenty of ground for all; but if a dispute should arise,
he would no doubt be able to settle it amicably with his neighbours,
by going to the place and hearing the evidence of the oldest Arabs
in the particular district and letting custom and tradition decide
the point.[143]
=Boundary between the Ashabab and Meleikab.=—This boundary is
defined in the Ministerial _Arrêté_ of June 25, 1902, to run along
the Wadi Hodein from the sea to Gebel Abraq, and thence southward
to Gebel Um el Tiur. The only difficulty in laying down this line on
the map is in deciding which part of the great plateau of Gebel Abraq
to take as the point, and which of the two Gebels Um el Tiur is meant.
With regard to Gebel Abraq (_see_ the large scale map on Plate
XV), the Wadi Hodein passes its south portion; but the context of
the _Arrêté_, defines the wells of Abraq (Bir el Sunta, Bir Abu
Dibesat, Bir Abraq, and Bir Gumbit) to be in the Meleikab area,
and as these lie further north it is obviously necessary, in the
spirit of the _Arrêté_, to take a point in the north portion of
Gebel Abraq. From an examination of the map on Plate XV it will be
seen that an easy and rational interpretation would be to regard the
triangulation point, marked by a beacon on the plateau 1,700 metres
north-west of Bir Abraq, as being a point on the boundary; the line
from Gebel Um el Tiur to pass through this point northwards till it
outs the Wadi Abraq, and thence the boundary line would lie along
the course of Wadis Abraq and Naam to Wadi Hodein. This boundary
fulfils the obvious intention of the _Arrêté_, and at the same
time has the advantage of being easily traceable on the ground.
As to the two Gebels Um el Tiur, I have already mentioned this
difficulty in connexion with the location of the administrative
boundary (_see_ p. 74), and have taken the higher of the two mountains
of the same name as being the one intended.
Before leaving the subject of the Meleikab boundaries, it may be
worth while to mention that at the time the _Arrêté_ of 1902 was
issued the country had not been surveyed; it was then thought that
Bir Shalatein lay some fifty kilometres further along the coast
southward than the mouth of Wadi Hodein, and the _Arrêté_ defined
the eastern boundary of the Meleikab territory to be the coast-line
from Wadi Hodein to Bir Shalatein. But as Bir Shalatein is actually
_in_ the Wadi Hodein, the real result is that the Meleikab area
ends in a point on the coast, and does not include any sea-board at
all. The matter is not one of great moment, because the coast-plain
for some distance southward of Wadi Hodein is very barren; but it
illustrates the impossibility of defining boundaries without either
going over the actual ground or having a reliable map.
=The Hamedorab Boundary.=—The Hamedorab claim their boundary to
run from Bir Meneiga southward along the watershed of Gebel Gerf,
along the east side of the basin of Wadi Diqdib to just south of Bir
Baaneit, thence to the hill called Kilia Arib, thence to the hill
of Eqrun, thence to the pass of Bani Sana; at Bani Sana the boundary
turns south-westward so as to pass west of Wadis Hamida and Nubitra,
then bends to the south-east passing west of Wadis Mashushenai and
Dibir, thence eastward along the south side of Wadi Di-ib.
PLATE XXVI.
[Illustration: SKETCH-MAP SHOWING TRIBAL BOUNDARIES
Ball—Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1911. (60-190)]
The Hamedorab state that much of the country included in the Egyptian
administration as belonging to the Ashabab is really Hamedorab
country; they claim the north limit of their tribal territory
to commence at the mouth of Wadi Khoda on the coast (in latitude
23° 42′) and to pass north of Wadis Khoda, Shenshef, and Shut,
thence southward passing west of Wadi Beida to Bir Meneiga.[144]
This is of course contrary to the Ministerial _Arrêté_ of 1902,
and as Bramly Bey (_The Anglo-Egyptian Sudan_, Vol. I, p. 93)
mentions that on the other hand the Ababda tribe assert that _their_
country should rightly extend south of the administrative boundary,
it is probable that the administrative frontier represents a fair
division of the rival claims.
=The Kurbeilab Boundary.=—The Kurbeilab claim their eastern boundary
to run as follows: From Bir Meneiga southward along the watershed
of Gebel Gerf to near the Sherefa pass, thence south-eastward
along the north side of Wadi Sherefa el Sharqi on to the small hill
called Tibashoi Tomokolat, thence east-north-eastward to Gebel Hamra
Dom. From Gebel Hamra Dom south-eastward to the hill of Osnei, thence
southward to the hills of Ti Keferiai, thence to the pass of Bani
Sana. From Bani Sana southward to Gebel Warabeit, thence along the
east side of Wadi Dibir, along the north side of Wadi el Qurat, across
Wadi Di-ib, and then southwards along the east side of Wadi Di-ib.
=The Balgab Boundary.=—The Balgab boundary coincides with the main
watershed from the parallel of 22° northwards to Gebel Adar Qaqa,
then passes between the drainages of Wadi Hasium and Wadi Soaorib
to the hill called Kulet Tinasal. From Kulet Tinasal the boundary
runs east-south-eastward across Wadi Soaorib, passing north of Wadi
Dishlo; thence it turns south along the mountains separating the
basin of Wadi Soaorib from that of Wadi Baueiwai, thence it passes
south of the heads of Wadi Miatit, eastwards across Wadi Aqwem,
along the north side of Wadi el Qurat, across Wadi Di-ib, and then
southwards along the eastern side of Wadi Di-ib.
=The Koatil Boundary.=—The Koatil claim their boundary to run
from the head of Wadi Diqdib, along the mountains forming the
eastern side of the basin of Wadi Diqdib to a point just south of
Bir Baaneit, thence eastward to Gebel Hamra Dom. From Hamra Dom,
west-south-westward to Tibashoi Tomokolat, thence along the north
side of Wadi Sherefa el Sharqi and along the mountains forming the
west side of the basin of Wadi Diqdib up to the head of that wadi.
The Koatil further claim as their territory the upper portion of
the basin of Wadi Medarai west of longitude 35° 18′.
The Koatil also own the well called Bir Um Rasein, though all the
wadis in its neighbourhood belong to the Kurbeilab.
=Overlapping of Claims.=—When the boundaries of the different tribes
as specified above are laid down on the map (_see_ Plate XXVI), it
is found that there are three tracts claimed by more than a single
tribe. These three disputed areas are:—
(1) A tract south and east of Bir Baaneit, claimed both by the Koatil
and by the Hamedorab. The western part of this area is relatively
well wooded. Its eastern portion includes the water source called
Ti Dabai Hamra Dom.[145]
(2) A tract extending southward from Gebel Hamra Dom to the Wadi
Qurat, claimed both by the Kurbeilab and by the Hamedorab. This
area includes the Wadis Hamida, Nubitra, and Dibir, and four not
very important water sources, _viz._, Galt Osnei, Megwel Hamida,
Bir Nubitra, and Bir Mashushenai.[146]
(3) A narrow tract including the Wadis Qurat and Di-ib, claimed by
all three tribes Balgab, Kurbeilab, and Hamedorab.
=Ownership of Water Sources.=—With the exception of the five
water sources just mentioned as lying within the areas claimed by
more than one tribe, there are no disputes about ownership of water
supplies. The wells of the different tribes are partly enumerated
in the _Arrêté_ of 1902, but as the list there given is far from
complete and many of the names are incorrect, I give below a list of
the water sources belonging to the various tribes within the area
surveyed. For particulars of the various water sources reference
should be made to Chapter VII (p. 234).
_Wells, etc., of the Ashabab._
Bir Muelih Bir Helie Igli Galt
Bir Ghadir Bir Abu Hashim Galt Um Tundeba
Bir Murra Bir Shenshef Zabara Galts
Bir Abu Had Bir Betan Ghuel Galts
Bir Um Gubur Bir Rahaba Galt Um Karaba (Migif)
Bir Masur Bir Abu Reye Megal Harami
Bir Ranga Bir Abu Beid Galt Um Gerifat
Bir Khashab Bir Gahlia Galt Um Gunud
Bir Abu Hamamid Bir Orga Galt Batoga
Bir Metawit Bir Um Reit Galt Um Maiat
Bir Shadli Amar Spring Galt el Aguz
Galt Seiga
_Wells, etc., of the Meleikab._
Bir el Sunta Bir Gumbit
Bir Abu Dibesat Bir Abu Saafa
Bir Abraq Bir Dif
Bir Beida
_Wells, etc., of the Hamedorab._
Bir Shalatein[147] Bir Meheriqa Bir Salalat O Sir
Bir Adal Deib[147] Bir Nabit Bir Sararat Serimtai
Bir Meneiga[148] Bir Abu Ramad Megwel Akau
Bir Muqur Bir Kansisrob Ti Kureitra
Bir Baaneit Bir Akwamtra Bir Frukit
Halaib Wells Bir Qabatit
_Wells, etc., of the Kurbeilab._
Bir Madi Bir Shinai Meis-heit-ar
Bir Korbiai Bir Kagog[149] Megwel Adar Aqdeib
Bir Meneiga[148] Bir Guqub Megwel Um Ein
Bir Sararat Seyet Bir Himeitra Megwel Um Edwa
Bir Bint el Dreb Bir Um Bishtit[150] Megwel Didaut[151]
Bir Odis Maaleq[149] Bir Qidmib Megwel Aqwem
Bir Abu Hodeid Bir Meisah[151] Galt Hilwit Hasium
Galt Kirir
_Wells of the Koatil._
Bir Diqdib
Bir Um Rasein
According to the _Arrêté_ of 1902, Bir Egat is Mallak property.
[Footnote 139: _See_ notes by Mr. W. E. Jennings Bramly in _The
Anglo-Egyptian Sudan_, edited by Count Gleichen. London, 1905. Vol. I,
pp. 91-93.]
[Footnote 140: Of these two sub-tribes (Mallak and Mohammad Omerab),
I did not hear anything during my travels. The Mallak country is
mostly south of latitude 22°, but extends into South-Eastern Egypt
round about Bir Egat, a locality which I did not visit. The Mohammad
Omerab are stated by Mr. Bramly (_op. cit._) to own the wells of Bir
Meisah and Megwel Didaut, which, as will be seen from what follows,
are included in the area claimed as Kurbeilab by the Sheikh who
accompanied me.]
[Footnote 141: The men were Sheikh Isa Ali Tiut, Sheikh of the
Hamedorab; Sheik Hatab (brother of Mohammad Katul, Sheikh of the
Kurbeilab); and Mohammad Katul Batkai, of the Kurbeilab-Aliab.]
[Footnote 142: In order to render it easier to follow the descriptions
of the boundaries, I have purposely omitted from this map most of
the place-names other than those mentioned in the descriptions. The
map is to the same scale as the general orographical map on Plate I.]
[Footnote 143: Jennings Bramly Bey, the Senior Inspector of Berber
Province, who has kindly favoured me with some useful criticisms
of this chapter, remarks: “My experience up to date is that
each principal man has a different idea of his own boundaries and
that those ideas differ from day to day. My impression is that the
Bisharin are as yet one big family, and that the grazing is ample
for all so that the boundaries are very vague between the different
tribes. Disputes of course do arise as to the possession of wadis,
but I find that a week after a certain wadi has been allotted to one
of two tribes, both tribes are amicably grazing in it side by side
without payment. The ownership of wells is more strictly defined.”]
[Footnote 144: Bir Shenshef and Bir Beida are in fact classed as
belonging to the Hamedorab in a MS. list of wells drawn up by Bramly
Bey. But he has doubtless so classed them before their true locality
was known; as they lie well to the north of the Sudan administrative
boundary (Shenshef is over one hundred kilometres from the nearest
point of that boundary, on the Egyptian side) the Hamedorab claim
can hardly be maintained.]
[Footnote 145: This water source is recorded in Bramly Bey’s
MS. list of wells as Hamedorab property.]
[Footnote 146: Mr. Bramly (_Anglo-Egyptian Sudan_, Vol. I, p. 92),
classes Bir Mashushenai as Koatil. I am, however, informed that there
are two wells of this same name, and this classification probably
refers to another well than the one mentioned above.]
[Footnote 147: The _Arrêté_ of 1912 ascribes these two wells to
the Ashab, a tribe of whom I heard nothing when in the neighbourhood;
Bramly Bey informs me that they are a sub-tribe of the Hamedorab.]
[Footnote 148: Joint Hamedorab-Kurbeilab.]
[Footnote 149: Bramly Bey, in his MS. list of wells already referred
to, classes Bir Odis and Bir Kadot (probably the same as my Kagog)
as Hamedorab. But they were not so claimed by the Hamedorab sheikh
who accompanied me, and lie well outside the Hamedorab boundary as
claimed by that sheikh.]
[Footnote 150: Bramly Bey informs me that the ownership of Bir Um
Bishtit is disputed between the Kurbeilab and Koatil, but the wadi
of the same name appears to be undisputed Kurbeilab ground.]
[Footnote 151: I have included these two water sources (Bir Meisah
and Megwel Didaut) in the Kurbeilab list, because they lie within the
boundary claimed for the Kurbeilab by the sheikh who accompanied me;
but according to Mr. Bramly (_Anglo-Egyptian Sudan_, Vol. I, p. 92)
they belong to the Mohammad Omerab.]
CHAPTER XIII.
* * * * *
=NOTES ON THE ROAD FROM HALAIB TO PORT SUDAN.=
* * * * *
On the completion of the survey work at Halaib in May 1908, I returned
to Cairo by marching in to Port Sudan and thence taking steamer
to Suez. The journey from Halaib to Port Sudan with baggage camels
occupied eleven days, travelling on an average thirty kilometres a
day. This rate of travel did not permit of any surveying being done
en route, but I took brief notes of the road and the wells on it,
and as this road does not appear to be included in those described
in the Sudan Handbook, I give here the notes I made. The distances
are estimated from the times occupied in marching.
I would mention that from Mohamed Ghul onwards to Port Sudan there are
two roads; a lower one near the sea, usually followed by the Police
patrols, and an upper one which goes a little distance inland. The
upper road was the one I followed, as my guides informed me that
while it was only some eight kilometres longer than the lower one,
there was much better water to be found on it.
In the sketch maps on Plates XXVII and XXVIII, I have shown the
road and the wells on it as correctly as is possible from my notes,
using the Admiralty Chart No. 2,336 as a basis for the coast-line
and the maps 36 I and 46 A, issued by the Sudan Survey Department,
for the position of Port Sudan and some topographical details. As
the direction of march was roughly north-to-south and the total
estimated distances between Halaib and Mohamed Ghul, and between
Mohamed Ghul and Port Sudan, agree pretty well with those scaled
from the maps after laying down the terminal positions correctly,
it may be taken that the latitudes of the wells are fairly correct,
while the longitudes are liable to greater error as being only
rough estimations.
PLATE XXVII.
[Illustration: Ball—Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1911. (190)
Rough Sketch of the Road from HALAIB TO MOHAMED GHUL]
PLATE XXVIII.
[Illustration: Ball—Geography & Geology of South-Eastern Egypt.
Photo-Metal-Process. Survey Dept. Cairo 1911. (190)
Rough Sketch of the Upper Road from MOHAMED GHUL TO PORT SUDAN
Scale 1:750,000.]
HALAIB TO MOHAMED GHUL.
------------------+--------------------+------------------------------
| Kilometres. |
Place. +-------------+------+ Description.
|Intermediate.|Total.|
------------------+-------------+------+------------------------------
=Halaib= | — | — |Village of Hamedorab Arabs
| | |(reed huts). Small fort of
| | |two storeys; tanks below
| | |and native police quarters
| | |above. No accommodation for
| | |Europeans. Several wells,
| | |with plentiful water, in
| | |and near the village. Water
| | |hard and aperient, but
| | |drinkable. Fish of good
| | |quality plentiful and cheap,
| | |from native fishermen. Small
| | |quantities of sugar, dates,
| | |fat, etc., can be got in the
| | |bazaar. No post nor telegraph
| | |nor regular communication.
| | |Rocks around village are
| | |limestones and gypsum, with
| | |some calcareous conglomerates.
| | |
Wadi Shellal | 4 | 4 |Road goes over sandy and
| | |gravelly undulating ground
| | |near sea. Wadi Shellal is a
| | |broad shallow wadi (scrub)
| | |coming from high mountains to
| | |the west.
| | |
Wadi Aqilhoq | 3 | 7 |Broad shallow wadi (scrub).
| | |About 19 km. up the wadi,
| | |west of the road, Bir Frukit,
| | |where there is a constant
| | |supply of better water than
| | |can be got at Halaib.
| | |
Wadi Aqwai | 4 | 11 | }
| | | } Shallow wadis with scrub.
Kreit-reit-or | 9 | 20 | }
| | |
Ti Kureitra | 2 | 22 |Four wells, about 12
| | |metres deep, lined with
| | |gypsum-slabs; about 4 km.
| | |from coast. Water bad
| | |(strongly purgative) only
| | |suitable for animals.
| | |Gypsum beds, partly covered
| | |by gravel, extend over a
| | |broad stretch round the
| | |wells. Further on, banks of
| | |calcareous grit, covered
| | |mostly with gravel.
| | |
Bir Qabatit | 18 | 40 |About 6 km. from Ti Kureitra,
| | |mass of high felsite hills
| | |called Gebel Hadarba,
| | |passed on right of road;
| | |road continues over sandy
| | |and gravelly undulating
| | |ground across shallow wadis
| | |draining from the hills.
| | |Bir Qabatit is a well in a
| | |small wadi south of the main
| | |Wadi Qabatit, about 1½ km.
| | |from the sea. Water about 5
| | |metres down, very salt, but
| | |was being drunk by the Arab
| | |patrols, who said it did not
| | |purge them.
| | |
Bir Ma-arob | 14 | 54 |Good road over coast-plain.
| | |At Bir Ma-arob, one well of
| | |bad water, strongly aperient.
| | |Well is in wadi, forming a
| | |pool about 2 metres diameter,
| | |overhung by tamarisk-bush.
| | |Water about 4 metres down
| | |from surface. NW. of the
| | |well, group of white hills,
| | |about 50 metres high, called
| | |Tishara, of calcareous grit.
| | |
Wadi Na-akreib | 8½ | 62½ |Road over sandy and gravelly
| | |plain, here crosses a broad
| | |shallow wadi.
| | |
Wadi Hamsiat | 5 | 67½ |Wadi draining into lagoons.
| | |
Wadi Waseb | 5 | 72½ |Wadi draining into a great
| | |inlet of the sea, looks like
| | |a good harbour.
| | |
Hibi Kwan | 3 | 75½ |Wadi draining into a large
| | |inlet. Coast about here much
| | |broken, with coral reefs and
| | |islets.
| | |
Bir Delaut | 12½ | 88 |Good road on to Bir Delaut.
| | |Three wells in alluvium of
| | |wadi, about 500 metres from
| | |sea. Water about 4 metres
| | |down. The southernmost well
| | |is the best. Water good.
| | |
| 3 | 91 |Road passes head of long
| | |inlet, then it passes east
| | |of a mass of limestone hills
| | |called Abu Hamama, about 200
| | |metres high. A little further
| | |on, another big inlet called
| | |Halaqa, close south of which
| | |are limestone-hills about 150
| | |metres high.
| | |
| 13 | 104 |Road passes west of limestone
| | |hills. Further on it crosses
| | |the wide and bushy Wadi
| | |Shenaab.
| | |
| 14 | 118 |Road turns sharply eastward
| | |through low hills (sandstones
| | |and grits underlying gypseous
| | |limestones, all dipping
| | |gently eastwards).
| | |
Megwel Shumab | 1 | 119 |Road passes close to Megwel
| | |Shumab, a shallow pit
| | |excavated in limestone with
| | |a little tunnel running
| | |eastwards. Water very bad,
| | |used only by animals.
| | |
| 5 | 124 |Road hitherto over undulating
| | |ground, here becomes nearly
| | |level.
| | |
Wadi Qumat Yawab | 10 | 134 |Road crosses broad shallow
| | |wadi.
| | |
Dungunab | 7 | 141 |Small village of huts and
| | |tents on coast. Good water
| | |at well about 3 km. inland.
| | |Mr. Crossland is carrying
| | |on work here in connexion
| | |with pearl-oyster industry.
| | |Meteorological station.
| | |
Tribal boundary | 9 | 150 |From Dungunab, road detours
| | |westward to round an inlet
| | |of the sea, then goes over a
| | |sandy and gravelly undulating
| | |plain with bushes and
| | |grasses. Boundary between
| | |Hamedorab and Amarar country
| | |marked by two wooden posts.
| | |
Wadi Hukeib | 3 | 153 |Road crosses wadi. High
| | |white hills, 10 km. to west
| | |of road; as seen through
| | |field-glass, these appear to
| | |be of white granite seamed by
| | |basic dykes. There is a good
| | |well, Bir Hukeit-ar, in Wadi
| | |Hukeib about 4 km. west of
| | |road and 5 km. from sea.
| | |
Wadi Yameinai | 8 | 161 |Broad wadi, wherein an acre
| | |or two has recently been
| | |planted with durra. About 6
| | |or 7 km. inland from this
| | |point, is a sheikh’s tomb,
| | |white and conspicuous in the
| | |morning light.
| | |
=Mohamed Ghul= | 8 | 169 |Small village on coast.
| | |Police fort with two decent
| | |rooms above, used by mamûr
| | |as office and quarters. No
| | |supplies worth mention.
------------------+--------------------+------------------------------
MOHAMED GHUL TO PORT SUDAN.
------------------+--------------------+------------------------------
| Kilometres. |
Place. +-------------+------+ Description.
|Intermediate.|Total.|
------------------+-------------+------+------------------------------
=Mohamed Ghul= | — | — |Small village on coast; see
| | |above.
| | |
| 16 | 16 |Road hitherto over gently
| | |rising plain of sand with
| | |grasses and bushes, here
| | |enters hills.
| | |
Bir Di-it | 1 | 17 |A number of very salt wells,
| | |used only by sheep and goats,
| | |sunk about 6 metres deep in
| | |the wadi bed and lined with
| | |masonry.
| | |
Bir Salalat Aseir | 27 | 44 |Good road from Bir Di-it
| | |among granite hills with
| | |intervening wadis and small
| | |plains, very grassy in
| | |places, to Bir Salalat Aseir,
| | |a masonry-lined well of good
| | |water, about 4 metres deep,
| | |sunk in the alluvium of Wadi
| | |Aseir. Small settlement of
| | |Amarar Arabs here.
| | |
| 2 | 46 |Road after winding among
| | |hills, here enters on level
| | |plains of granitic sand, with
| | |grasses and bushes.
| | |
| 19 | 65 |Rocks change from granite to
| | |sandstones and limestones;
| | |road now winds among low
| | |banks.
| | |
| 8 | 73 |Road goes through east part
| | |of a mass of low hills.
| | |
Bir Eit | 19 | 92 |After passing the
| | |above-mentioned hills, the
| | |road continues over gently
| | |undulating ground with broad
| | |sandy wadis with grasses
| | |and bushes alternating with
| | |strips of igneous gravel.
| | |There are low flat-topped
| | |hills of limestone (beds
| | |dipping gently seawards)
| | |between the road and the
| | |sea. Bir Eit is on the road;
| | |it is a masonry-lined well
| | |about 5 metres deep sunk in
| | |the wadi-alluvium close to
| | |some scarps of white gritty
| | |limestone. Water very good.
| | |(N.B.—There is another
| | |Bir Eit in the same wadi
| | |lower down near the sea, of
| | |slightly bitter water). Small
| | |settlement of Amarar Arabs.
| | |Hills round Bir Eit rise at
| | |least 100 metres above the
| | |wadi, coral overlying marly
| | |and gypseous beds.
| | |
Low gravel hills | 8 | 100 |Road over undulating sandy
| | |and gravelly ground to two
| | |low gravel hills.
| | |
Tower | 12 | 112 |Road over sandy plain with
| | |dried-up scrub and occasional
| | |small patches of igneous
| | |gravel, passes 1 km. west of
| | |a small tower on a low gravel
| | |bank.
| | |
Wadi Ga-awit-reb | 4 | 116 |Ground broken by
| | |drainage-lines. Small trees
| | |and a few Arab huts. Megwel
| | |Ga-awit-reb, a water source
| | |in the wadi a little below
| | |where road crosses it.
| | |
Bir Ta-amai | 11 | 127 |Road over gently rising very
| | |sandy ground to Wadi Arba-at,
| | |a sandy wadi with numerous
| | |trees. Bir Ta-amai is a well
| | |in Wadi Arba-at, a little to
| | |the west of the road, where
| | |the latter passes between two
| | |masses of low igneous hills.
| | |Water good, about 7 metres
| | |down. Rude hut near well.
| | |
| 10 | 137 |Chimneys of Port Sudan here
| | |become visible in distance
| | |on clear day. Road lies over
| | |sandy plain.
| | |
=Port Sudan= | 20 | 157 |Rail connexion with Atbara
| | |and Suakin. Post and
| | |telegraph. Regular steamers
| | |to Suez. Permit from British
| | |Consul necessary before
| | |fire-arms can be taken on
| | |board steamers.
------------------+--------------------+------------------------------
INDEX.
* * * * *
=A=
Ababda Arabs, 32.
„ geographical terms, 34.
Abraq springs, 122.
Abraq springs, biotite-granite near, 274.
Abraq springs, serpentine near, 325.
Absciel (Abu Seyal), old mines at, 353.
Abu Beid Hills, red gneiss of, 335.
„ el Feda, 2.
„ Hashim Hills, 209.
„ Hodeid Ogla, 214.
„ Medrik, Gariat, 30.
„ Rahal well, 238, 260.
„ Saafa springs, 118.
„ Seyal (Absciel), old mines at, 353.
Actinolite-schists, 343.
Adar Aqdeib, 222.
„ Ameit, 221.
„ Aweib, 224.
„ Aweib Um Bishtit, 219.
Adatalob Adara, 222.
„ Hadal, 222.
Admiralty Surveys, 6.
Admiralty positions, comparison of, 65.
African Reefs, Ltd., 28.
_Agathon_, 2.
Agriculture, 35.
Akla Da-Aiyob, 147.
Alafot, 231.
„ Onqwab, 231.
Aliab tribe, 366.
Alluvial deposits, 253.
Amarar boundary, 375.
Amphibolites, 316.
„ serpentine from, 323.
Andesites, 295.
„ altered to schists, 342.
Animal life, 24.
Ankalidot, 221.
Antiquities, 28.
Antonine Itinerary, 2.
Aplite, 272.
_Apollonus_, 11.
Arabs, 32.
_Aristonis_, 11.
Asbestos, 330.
Ashabab tribe, 366.
„ boundary of territory of, 367.
„ wells of, 371.
Ass, wild, 24.
Astronomical observations, 42.
Asut Duk pass, 159.
Augite-diorite, 289.
Augite-porphyrite, 293.
_Aydat_, 12.
Azimuth, method used in observations for, 47.
Azimuths, summary of observed, 48.
=B=
Bakewell, Mr. O. N., 17.
Balgab tribe, 366.
Balgab tribe, boundary of territory of, 369.
Bani Sana pass, 153.
Baqari Daba, 219.
Barth, 7.
Basalt, 310.
Base-lines, 39.
Basic dykes, serpentinised, 323.
„ igneous rocks, 296.
Beach deposits, 252.
Beacons at triangulation-stations, 40.
Bedouin tribes, 366.
Belzoni, 4.
Bent, 12.
Berenice, foundation of, 1.
„ position of, 65.
„ temple of, 29.
Berget Abu Sarib, 216.
Beryl, 345.
Biotite-granite, 273.
Bir Abraq, 123.
„ „ serpentine near, 325.
„ Abu Beid, 125.
„ „ Dibesat, 123.
„ „ Had, 104.
„ „ Hamamid, 84.
„ „ Hashim, 88.
„ „ Hodeid, 141.
„ „ Ramad, 157.
„ „ Reye, 114.
„ Adal Deib, 151.
„ Akwamtra, 156.
„ Baaneit, 138.
„ Beida, 133.
„ Betan, 124.
„ Bint el Dreb, 139.
„ Delaut, 374.
„ Dif, 126.
„ Di-it, 376.
„ Diqdib, 138.
„ Egat, 91.
„ Eit, 376.
„ Frukit, 162.
„ el Gahlia, 115.
„ Ghadir, 100.
„ Gumbit, 123.
„ Guqub, 92.
„ Helie, 83.
„ Heliwat, 79.
„ Himeitra, 91.
„ Kagog, 140.
„ Kansisrob, 158.
„ Khashab, 86.
„ Korbiai, 134.
„ „ serpentines near, 328.
„ Ma-arob, 374.
„ Madi, 130.
„ Mashushenai, 152.
„ Masur, 89.
„ Meheriqa, 150.
„ Meisah, 147.
„ Meneiga, 134.
„ „ magnesite-veins near, 330.
„ „ serpentines near, 329.
„ Metawit, 87.
„ Miaus, 91.
„ Muelih, 80.
„ Muqur, 137.
„ „ magnesite and asbestos near, 330.
„ Murra, 79.
„ Nabit, 156.
„ Nubitra, 154.
„ Odis Maaleq, 141.
„ Orga, 119.
„ Qabatit, 163, 373.
„ Qidmib, 144.
„ Qoleib, 84, 238.
„ Rahaba, 114.
„ el Ranga, gypseous deposits near, 258.
„ Salalat O Sir, 156, 159.
„ Sararat Serimtai, 159.
„ Shadli, 86.
„ Shalatein, 120.
„ Shenshef, 113.
„ Shinai, 140.
„ Sibrit, 82.
„ el Sunta, 122.
„ Ta-Amai, 377.
„ Um Bishtit, 145.
„ „ Gubur, 79.
„ „ Rasein, 143.
„ „ Reit, 117.
Birds, 24.
Bisharin Arabs, 32.
„ geographical terms, 34.
Bodkin peak, 200.
Botany, 25.
Boundaries, administrative, 74.
Boundaries, tribal, 366.
Bramly, Mr. W. E. Jennings, 366.
Breccias, 350.
_Brissus carinatus_, 252.
Bruce, 3.
=C=
Cailliaud, 3, 345.
Calcareous schists, 348.
„ tufa, 257.
Calcite, in mica-schists of Sikait, 346.
„ in veins at Romit, 353.
Camel-breeding, 35.
Camel-transport, cost of, 35.
Campbell, Mr. J. Morrow, 15, 21, 92.
Cannon-ball weathering of diabase, 307.
Chalybite, 353.
Charcoal-burning, 35.
Chauvenet, 42, 47.
Chlorite-schists, 346.
Clay-schists, 337.
Climate, 22.
Coast-line, 22.
„ method of surveying, 72.
Coast-plain, slope of, 22.
Colston and Purdy, 9.
Compass, disturbance of, by magnetic rocks, 77, 321.
Compass, variation of, 75.
Computation-methods, 41.
_Contra-Apollinopolis_, 29.
Copper in quartz veins, 352.
Cora, 10.
Coral-reefs, 251.
Coral-reefs, conditions for growth of, 365.
Cretaceous sea, 364.
=D=
Da-aiyob, 34.
Dahab Eff. Hassan, 17.
D’Anville, 2.
Darahib, 89.
„ Baaneit, 138.
Diabase, 305.
„ resembling serpentine, 328.
„ altered to serpentine, 329.
Diodorus Siculus, 2, 27.
Diorite, 286.
„ augite-, 289.
„ mica-, 290.
Diorites crushed into schists, 340.
Diorite-gneiss, 334.
Diorite-porphyrite, 291.
Doves, 24.
_Dracaena_, 229.
Dragon’s-blood tree, 229.
Dungunab, 375.
Dunites, 319.
„ serpentines from, 323, 325.
Dunn, Mr. S. C., 27.
Dykes, 362.
=E=
Edrisi, 2.
Einiwai Hill 221.
„ basalt of, 311.
Eir Arib, 224.
Emeralds, 345.
Eocene rocks, possible former extension of, 356.
Eqrun, 221.
Erf Abu Homur, 195.
Erf el Fahid, 172.
„ „ amphibolite near, 318
„ „ quartz-rock of, 266.
„ „ serpentine near, 321.
„ el Gimal, 193.
„ el Mohaib, 195.
„ el Sagur, 173.
„ Um Araka, 197.
„ Rod Um Rashid, 173.
=F=
Falacro, 11.
Fault-breccias, 351.
Faults in Nubian sandstone, 358.
Ferrar, Mr. H. T., 258.
Fishing, 36.
Floyer, Mr. E. A., 11.
=G=
Gabbro, 296.
Gabbroid rocks, serpentines derived from, 328.
Galts, 25, 240.
Galt el Aguz, 88, 240.
„ Batoga, 111.
„ Um Tundeba, 99.
Garia Kalalat, 111.
Gariat Abu Medrik, 30.
Gazelles, 24.
Gebel Abarun, 180.
„ Abgeya, 210.
„ el Abiad, 183.
„ Abraq, 204.
„ „ sandstone-beds of, 360.
„ Abu Argub, 177.
„ „ Arta, 197.
„ „ Brush, 210.
„ „ Dahr, 195.
„ „ „ serpentine of, 324.
„ „ „ splintery schists near, 337.
„ „ Derega, 187.
„ „ Ghalqa, 189.
„ „ Ghusun, 182
„ „ Gurdi, 186.
„ „ „ schists of, 340.
„ „ Hamamid, 175.
„ „ „ breccia of, 351.
„ „ „ diabase of, 307.
„ „ „ schists of, 341.
„ „ Hegilig, 184.
„ „ Hegilig, biotite-granite near, 273.
„ „ Hegilig, mica-diorite dyke of, 290.
„ „ Hireiq, 213.
„ „ „ aplite of, 272.
„ „ Hodeid, 213.
„ „ „ diorite-porphyrite of, 291.
„ „ „ Ogla, 214.
„ „ Husenat, 197.
„ „ Khrug, 168.
„ „ Rahia, 209.
„ „ Shigelat, 193.
„ „ Sieiyil, 197.
„ Adar Qaqa, 219.
„ „ „ muscovite-granite of, 274.
„ el Adraq, 225.
„ Allawi, 174.
„ „ calcareous tufa, of, 251.
„ „ diorite of, 286.
„ „ graphite-schist of, 350.
„ Amba-ut, 174.
„ el Anbat (Wadi Kharit), 180.
„ „ „ augite-diorite of, 290.
„ „ (Wadi Hodein), 198.
„ „ schists of, 339, 348.
„ Anfeib, 204.
„ „ sandstone-beds of, 360.
„ Anweiyib, 224.
„ Aqab el Negum, 207.
„ Arais, 197.
„ Atut, 171.
„ „ olivine-gabbro of, 302.
„ Awamtib, 201.
„ „ sandstone of, 359.
„ Baid el Khuruf, 209.
„ Balatitda (near Bir Meheriqa), 231.
„ „ (near Bir Frukit), 233.
„ Batoga, 190.
„ Beida, 217
„ „ diorite of, 288.
„ Belamhandeit, 197.
„ Butitelib, 205.
„ „ altered quartz-felsite of, 280.
„ Dagalai, 202.
„ Dahanib, 192.
„ „ gabbro of, 298.
„ el Deheis, 210.
„ Derera, 169.
„ Derhib, 186.
„ Dibag, 191.
„ Dif, 205.
„ „ sandstone-beds of, 360.
„ Dreb, 213.
„ Duag, 225.
„ Durunkat, 180.
„ Dweig, 168.
„ Egat (near Wadi Kharit), 185.
„ Egat (near Wadi Alaqi), 225.
„ Elba, 227.
„ Elba, hornblende-granite of, 274.
„ Eqrun, 221.
„ Eqrun, schists of, 343.
„ Etresia, 207.
„ Etus, 207.
„ Faraid, 199.
„ Felieiti, 195.
„ Fereyid, 200.
„ „ granite of, 269.
„ „ kersantite dyke at, 294.
„ Geneina Gharbi, 194.
„ „ Sharqi, 194.
„ Gerf, 210.
„ „ serpentines of, 327.
„ Geror, 223.
„ Ghadir, 174.
„ „ quartz-felsite of, 279.
„ „ serpentine of, 323.
„ el Ghar, 195.
„ Ghuel, 170.
„ „ calcareous tufa of, 257.
„ Guqub, 225.
„ Gumudlum, 185.
„ Hadarba, 233.
„ „ rocks of, 281.
„ Hadal Derqa, 214.
„ Hagar Dungash, 172.
„ Hafafit, 166.
„ „ grey gneiss of, 335.
„ Hamata, 180.
„ „ quartz-felsite of, 278.
„ „ hornblende-granite of, 275.
„ „ green breccia of, 351.
„ Hamida (near Wadi Baueiwai), 223.
„ „ (near Wadi Baueiwai), talcose schist of, 348.
„ „ (near Wadi Alaqi), 225.
„ Hamra Dom, 216.
„ „ Dom, stratified rocks near, 256.
„ Hamra Tit, 220.
„ Hamrat el Feg, 207.
„ Hamrat Mukbud, 178.
„ „ „ granite of, 270.
„ „ „ dykes at, 272.
„ Hamrat Selma, 168.
„ Hamrat Wogud, 173.
„ Hangalia, 169.
„ Hanquf, 232.
„ Harhagit, 198.
„ Hateib, 225.
„ el Heda, 179.
„ Hefeiri, 184.
„ Heianai, 225.
„ Heleikonti, 225.
„ Hendusi, 197.
„ Hilwit Hasium, 214.
„ Himeitra, 225.
„ Hindia, 198.
„ Hodein, 204.
„ Homr Akarim, 178.
„ el Homur, 187.
„ Humariai, 217.
„ Igli el Ahmar (el Atshani), 171.
„ Igli el Iswid (el Rayani), 171.
„ „ „ rocks of, 281.
„ Is, 220.
„ Iteima, 173.
„ Kahfa, 177.
„ „ granite-porphyry dykes of, 276.
„ „ trachyte dykes of, 285.
„ Kala, 206.
„ Kalalat, 191.
„ Khashab, 217.
„ Khashir, 185.
„ Khulla, 179.
„ Kolaiqo, 217.
„ „ quartz-felsite dykes of, 278.
„ Korabkansi, 214.
„ „ serpentine of, 329.
„ Korbiai, 211.
„ Kulyeit, 210.
„ Leqaq, 220.
„ Lewewi, 174.
„ Lilowit, 205.
„ el Mahali, 180.
„ „ rocks of, 281.
„ Mansur Diab, 214.
„ Marasan, 178.
„ Mashushenai, 223.
„ Medarai, 213.
„ Medsus, 178.
„ Meis-heit-ar, 219.
„ Meneiga, 211.
„ Metawit, 178.
„ Miatit, 221.
„ Mikbi, 185.
„ Migif, 167.
„ „ microcline of, 272.
„ Mishbih, 208.
„ „ granite of, 275.
„ Mowisat, 209.
„ Muelih, 172.
„ „ hornblende-granite of, 275.
„ „ quartz-felsite dykes of, 280.
„ Mudergeg, 169.
„ Muktil, 168.
„ Mulgata, 209.
„ Muqsim, 226.
„ „ chlorite-schist of, 347.
„ Muqur, 211.
„ el Naga, 209.
„ Natetiai, 207.
„ Nazla, 168.
„ „ syenite of, 283.
„ Nesheb Hasan, 210.
„ el Nekeiba, 195.
„ Niqrub el Foqani, 205.
„ Niqrub el Tahtani, 205.
„ Nubitra, 223.
„ Nuggur, 209.
„ Nugrus, 165.
„ Nukheira, 179.
„ Orga, 197.
„ Orgem, 219.
„ O Sir Eirab, 231.
„ Qidmib, 219.
„ Ranga, hæmatite at, 298.
„ „ sandstones of, 360.
„ Ras Abu Etl, 179.
„ Ras el Kharit, 185.
„ Ras Shait, 169.
„ Ras Shait, chrolite-schists near, 347.
„ Ras Um Gamil, 175.
„ Reietit, 209.
„ Reyan, 193.
„ Ribdab, 210.
„ „ chlorite-schist of, 347.
„ Romit, 209.
„ Sabahia, 173.
„ „ hornfels near, 344.
„ Sarobi, 184.
„ Seiga, 209.
„ el Sela, 231.
„ Selaia, 187.
„ „ gabbro of hill near, 302.
„ Shabih, 208.
„ Shanaiyet, 225.
„ Shebakhit, 202.
„ Shellal, 232.
„ Shendib, 232.
„ „ felsite from, 280.
„ Shendodai, 232.
„ Shenshef, 191.
„ Sheyenit, 208.
„ Shiab, 221.
„ Shigigat, 207.
„ Shoab, 184.
„ Shut, 193.
„ Shweib, 208.
„ Sikait, 174.
„ „ graphite-schists of, 350.
„ „ mica-schists of, 345.
„ „ talc-schists of, 348.
„ Soaorib, 220.
„ Sufra, 168.
„ „ andesite of, 295.
„ Suhin, 225.
„ Sukari, 173.
„ Sul Hamid, 231.
„ Suruk, 221.
„ Tarfawi, 182.
„ Tibatib, 205.
„ Tishushi, 222.
„ Tishushi Tiboki, 222.
„ Um el Abbas, 184.
„ Um Akra, 199.
„ „ Bisilla, 193.
„ „ „ granite-porphyry dykes of, 276.
„ „ „ olivine-gabbro of, 301.
„ „ „ troctolite of, 304.
„ „ Dalalil, 172.
„ „ Ein, 223.
„ „ Ein, amphibolite of, 317.
„ „ Etli, 199.
„ „ Gamil, 175.
„ „ Ghalqa, 209.
„ „ Goradi, 187.
„ „ Goraf, 169.
„ „ Gotto, 209.
„ „ Gunud, 188.
„ „ „ amphibolite of hills around, 316.
„ „ Guruf, 197.
„ „ Harba, 203.
„ „ „ sandstone of, 358.
„ „ Hasidok, 180.
„ „ Hegilig (near Wadi Naait), 189.
„ „ Hegilig (near Wadi Shut), 193.
„ „ Heshenib, 182.
„ „ „ diorite-porphyrite of, 292.
„ „ Huk, 189.
„ „ el Kalala, 208.
„ „ Khafur, 203.
„ „ „ sandstone of, 358.
„ „ Khariga, 170.
„ „ „ mica-diabase of, 310.
„ „ Krush, 210.
„ „ Laham, 182.
„ „ Maiat, 189.
„ „ Markha, 207.
„ „ Moghar, 166.
„ „ Rasein, 215.
„ „ „ granite-gneiss of, 333.
„ „ Regeba, 167.
„ „ Reit, 207.
„ „ „ felsite dykes of, 280.
„ „ Rewat, 209.
„ „ Sedri, 179.
„ „ Seleim, 220.
„ „ Sellim, 185.
„ „ Semiuki, 177.
„ „ „ hornfels of, 344.
„ „ Serg, 168.
„ „ Sididad, 204.
„ „ Sueh, 184.
„ „ Suerab, 179.
„ „ Tenedba, 198.
„ „ „ diorite of, 288.
„ „ „ serpentine of, 326.
„ „ el Tiur, 180.
„ „ el Tiur el Foqani, 225.
„ „ el Tiur el Tahtani, 225.
„ „ Tundeba, 173.
„ „ Usher, 180.
„ Wadhait, 215.
„ Waqif, 208
„ Warabeit, 223.
„ Zabara, 169.
„ „ clay-schists of, 337.
„ „ mica-schists of, 345.
„ „ talc-schists of, 348.
„ Zatit, 185.
„ Zergat Naam, 193.
„ „ „ dykes of, 282.
„ „ „ syenite of, 283.
„ „ „ schists of, 342
„ „ „ calcareous breccias near, 351.
„ Ziraga, 209.
Geli, ruins at, 101.
Geographical co-ordinates, method of computing and plotting, 41.
Geological Survey, 14.
Geziret el Dibia, 161.
„ Halaib el Kebir, 161.
„ Kwolala, 161.
Gimeida Hill, 216.
„ „ basalt of, 311.
Gneisses, 333.
Gneisses and schists, age and origin of, 363.
Gold in quartz-veins, 352.
Gold-mines, _see_ Mines.
Golénischeff, 10.
Government, 37.
Grain el Rih, 110, 189.
Granite, 267.
„ biotite-, 273.
„ hornblende-, 274.
„ muscovite-, 274.
„ pegmatitic, 270.
Granite-gneiss, 333.
Granite-porphyry, 276.
Graphite-schists, 350.
Gypsum and gypseous limestones, 257.
=H=
Hadal Aweib Meisah, 218.
Hadal Aweib Meisah, hypersthene-gabbro of, 300.
Halaib, 65, 159, 373.
„ water of, 238.
„ gypseous rocks of, 258.
Hagar el Fil, 193.
Halal Hendiyeb, 150.
Hamedorab tribe, 366.
„ „ boundary of territory of, 368, 375.
„ „ wells of, 371.
Hamiskul Hills, 209.
Hamra, el, 172.
Hamrat Mastura, 172.
Hanqun Ra-ub, 148.
Harzburgites, 319.
„ serpentine from, 329.
von Heuglin, 7.
Hibi Kwan, 374.
Hitan Shenshef, 113.
Hohait (tree), 229.
Hornblende-granite, 274.
Hornblende-picrites, 319.
„ serpentinisation of, 325.
Hornblende-schists, 338.
Hornfels, 344.
Hull, Prof., 12.
Hume, Dr. W. F., 117, 258, 298, 360.
Hydrography, 20.
Hypersthene-gabbro, 300.
=I=
I Hubal, 252.
Iarih Meisah, 219.
Ibex, 24.
_Ichthyophages_, 2, 36.
Igneous rocks, 262.
„ „ age of, 363.
„ „ classification of, 264.
Industries, 35.
Insects, 24.
Intermediate group of igneous rocks, 283.
=J=
James, Mr., 346.
Jidda, means of revising longitude of, 67.
Jomard, 3.
=K=
Kab el Haram, 106.
Kanais, 29.
Karam Elba, 230.
Karam Hindi, 158.
Kersantite, 294.
Khamsin, 23.
Khasheib Abu Daba, 189.
Khusa el Faraon, 173.
Kikeiyet Gharbi, 222.
Kikeiyet Sharqi, 222.
Kilia Arib, 216.
Koatil tribe, 366.
„ „ boundary of territory of, 370.
„ „ wells of, 371.
Kolmanab Hill, 221.
„ „ pyroxene-granulite of, 304.
Koptos-Berenice road, 29.
Koss, Lieut., 65.
Kreishim Hill, 231.
„ „ granite-porphyry of, 276.
Kreit-reit-or, 162, 373.
Kuatianai, 163.
Kubban, ancient copper-smelting at, 353.
Kulet Meigrum, 220.
„ Tinasal, 220.
Kurbeilab tribe, 366.
„ tribe, boundary of territory of, 369.
„ wells of, 371.
Kurdeman, 99, 173.
Kwat Hewah, 139.
=L=
Labour, cost of Arab, 35.
Latitude, method used in determination of, 42.
Latitudes of points on Red Sea, 65.
Latitudes, summary of observed, 47.
Lavas, 361.
Levels, methods used in determination of, 49.
Lherzolites, 319.
„ serpentines from, 322.
Limonite in schists, 348.
„ in veins, 353.
Linant de Bellefonds, 4, 33.
Local attraction of plumb-line, 47.
Longitudes of points on Red Sea, 66.
=M=
Macalister, Mr., 13.
Mack, Mr., 28.
Madaret Um Gamil, 175.
Magnesite, 330.
Mallak tribe, 366.
Marble, 349.
Marwot Elemikan, 188.
„ Elemikan, quartz-rock of, 265.
„ Rod el Ligah, 173.
„ Rod el Ligaia, 172.
„ Rod el Ligaia, aplite of, 273.
Medina Nugrus, 106.
Megal, 25.
Megal el Harami, 105.
Megal el Selaia, 84.
Megwel, 25.
Megwel Adar Aqdeib, 153.
„ Akau, 158.
„ Aqwem, 154.
„ Didaut, 153.
„ Hamida, 155.
„ Shumab, 374.
„ Um Edwa, 147.
„ Um Ein, 154.
Meis-heit-ar, 147.
Meleikab tribe, 366.
„ tribe, boundary of territory of, 367.
„ tribe, wells of, 371.
Meneiga, ruins at, 31.
Mersas, 252.
Mersas, near Halaib, 161.
Mersa Shab, 216.
Metamorphic rocks, 331.
„ „ probable age and origin of, 363.
Mica-diabase, 310.
Mica-peridotites, 319.
„ „ serpentine from, 321.
Mica-schists, 345.
Mikeriba, 230.
Mineral products, 27.
Mineral veins, 352.
Mines, ancient, 1, 27, 30.
„ „ at Abu Seyal (Absciel), 353.
„ „ near Gebel Allawi, 100, 174.
„ „ at Gebel Sukari, 99.
„ „ at Gebel Zabara, 99, 169, 345.
„ „ at Kurdeman, 99.
„ „ at Romit, 222.
„ „ at Sikait, 106, 174, 345.
„ „ at Um Eleiga, 125.
„ „ at Um el Huetat, 172, 348.
„ „ in Wadi Betan, 124.
„ „ in Wadi Egat, 91.
„ „ in Wadi Hangalia, 81.
„ „ in Wadi Nugrus, 106.
„ „ in Wadi Sabahia, 99.
„ „ in Wadi Salib Abiad, 112.
„ „ in Wadi Um Dafiri, 100.
Mining-leases, 28.
Miocene, sinking of land during, 364.
Mira Kwan, 159.
Mitba, 144.
Miti Kwan, 91.
Mohamed Ghul, 375.
Mohamed Omerab tribe, 366.
_Mons pentadactylus_, 24, 199.
Moresby, 6.
Mountains and hills, 19, 164.
Mukawar Island, 109.
Muscovite-granite, 274.
=N=
Nahud, el, 168.
„ syenite of, 283.
_Nechesia_, 7.
_Novum hydreuma_, 11.
Nubian sandstone, 259.
„ „ former extent of, 356.
„ „ present distribution of, 357.
„ „ structural features of, 357.
„ „ faults in, 358.
„ „ igneous intrusions in, 260, 357.
„ „ fossils of, 260.
=O=
O Harbub, 151.
O Shakafa, 219.
O Wota, 231.
Oligocene a period of land-sculpture, 364.
Olivine-diabase, serpentine from, 326.
Ophicalcite, 323.
Orthography of place-names, 16.
Osnei, 222.
Ostrich, 24.
=P=
Partridges, 24.
Pegmatitic granite, 270.
Peridot and Egyptian Gems Co., 28.
Peridotites, 319.
Picrolite, 330.
Place-names, orthography of, 16.
„ „ Ababda and Bisharin, 34.
Plane-table, use of, in surveying, 68.
Plant-life, 25.
Pliocene and Recent elevation of the land, 364.
Plumb-line, local attraction of, 47.
Plutonic rocks, relative ages of, 362.
Pluvial period, evidences of, 354.
“Pola” expedition, 13, 65.
Port Sudan, 377.
_Prionotus mons_, 8.
Prospecting licenses, 28.
Ptolemy’s Geography, 2.
Purdy and Colston, 9.
Pyroxene-granulite, 304.
Pyroxenites, 315.
„ serpentine from, 327.
=Q=
Qara Saba, 222.
Qash Amir, 231.
„ „ marble near, 349.
Qrein Salama, 216.
„ „ amphibolite of, 318.
Quartz-rock, 265.
Quartzites, 335.
Quartz-felsite, 277.
Quartz-schists, 335.
Quartz veins, 352.
=R=
Rainfall, 23.
Raised beaches, 252.
Ras Benas, hills of, 190.
„ „ rocks of, 252, 258.
Reconnaissance for triangulation, 40.
Red Sea, origin of, 355, 364.
„ position of principal points on, 65.
Refraction, terrestrial, 49.
Roads, 36.
Road from Halaib to Port Sudan, 372.
Rock-basins, 240.
Rock-inscriptions, 31.
Rocks, igneous, 262.
„ metamorphic, 331.
„ sedimentary, 251.
Rod Anut Berer, 142.
„ el Atut, 81.
„ Elbel, 115.
„ el Geneina, 83.
„ Hauanin, 93.
„ el Hendusi, 125.
„ el Kharuf, 83.
„ el Ligah, 81.
„ el Ligaia, 81.
„ „ diorite of, 287.
„ „ talc-schists of, 348.
„ Mukrayib, 131.
„ el Nagi, diabase-sheet in, 306.
„ Um el Farag, 81.
Romit mines, 222.
„ „ chalybite and calcite at, 352.
„ „ diorite of, 288.
„ „ talc and chlorite-schist of, 348.
=S=
Samut, well and ruins at, 30.
Sand-dunes, 252.
Sand-grouse, 24.
Sandstone, Nubian, 259.
Sarob Kwan, 147.
Sarrarab tribe, 366.
Scenery, types of, 23.
Schweinfurth, Prof. G., 8, 25, 229.
Scragged Hill, 231.
Serpentine, 320.
„ formation and cause of shattering of, 314.
„ alteration-products of, 330.
Shadly, Sheikh, 31, 86.
Shenshef, ruins, at 31, 113.
Sikeit Hill, 190.
Sikeit Hill, granite of, 269.
Shekra el Delam, 150.
Splintery schists, 337.
_Smaragdus mons_, 2.
Springs, 234.
Stewart, Mr. Charteris, 260, 347.
St. Johns Island, position of, 65.
„ „ peridot-mines at, 28.
Strabo, 2.
Streeter, Mr. E., 346.
Stuart, Mr. Villiers, 40, 224.
Suakin el Qadim, 158.
Sudan surveys, connection with, 48.
Suess, Prof., 27, 355.
Sulphur at Ras Benas, 190, 258.
„ at Bir el Ranga, 258.
Syenite, 283.
„ crushed into schists, 339.
Syenite-porphyry, 285.
=T=
Taar Ara, 231.
Tacheometric methods, 68.
Tahaqayet, 221.
Takrat Riba, 230.
Talc-schists, 348.
Talet Kurit, 118.
„ Um Danaqa, 118.
„ Um Karaba, 125.
„ Um Sideri, 118.
Taxes, 37.
Tectonics, 354.
Temples, 29.
Tibansi Tikam Ankwei, 217.
Tibashoi, 216.
Ti Dabei Hamra Dom, 146.
Ti Keferiai, 222.
Ti Keferiai, rocks of, 313, 351.
Ti Kureitra wells, 162, 238, 373.
Ti Kureitra wells, gypsum of, 258.
Tilat Tihu Shana, 138.
Timaiakwaia, 233.
Tinadei, 221.
Ti Qireira, 218.
Titailibab, 221.
Tombs, 31.
_Topazos Insula_, 2.
Topographical mapping, 68, 71.
Tourmaline, 346.
Trachyte, 285.
Transport of water, 242.
Triangulation-methods, 39.
Triangulation-computations, 41.
Triangulation, minor, 71.
Triangulation, use of vertical angles in, 50.
Triangulated positions, summary of, 50.
Tribal boundaries, 366.
Troctolite, 303.
_Troglodytes_, 2.
Tufa deposits, 257.
Tuquqî, 216.
=U=
Uhlemann, 31.
Ultra-acid igneous rocks, 265.
Ultra-basic igneous rocks, 313.
Umarawi, 216.
Um Eleiga mines, 125.
„ Eleiga mines, diorite-porphyrite of, 292.
„ Eleiga mines, gabbro of, 299.
„ Gerifat water-holes, 103.
„ Himar, 172.
„ el Huetat Hills, 172.
„ „ chlorite and talc-schists of, 347, 348.
„ Moghar peak, 166.
=V=
Venizelos, Mr., 28.
Vertical angles, use of, in triangulation, 50.
_Vetus hydreuma_, 11.
Volcanic rocks crushed into schists, 341.
=W=
Wad el Qireira, 153.
Wadai el Anz, 106.
Wadai el Nom, 105.
Wadis, importance of, 12.
Wadis draining to the Nile, list of, 78.
Wadis draining to the Red Sea, list of, 94.
Wadi Abarun, 83.
„ Abiad (tributary of Wadi Kreiga), 135.
„ el Abiad (tributary of Wadi Rahaba), 115.
„ el Abiad lil Huluz, 102.
„ Abraq, 122.
„ Abreik, 108.
„ Aideib, 157.
„ Alaqi, 89.
„ Alfawi, 91.
„ Allawi (tributary of Wadi Ghadir), 100.
„ Allawi (tributary of Wadi Khoda), 112.
„ Abu Argub, 83.
„ „ Beid el Abiad, 125.
„ „ Beid el Azrak, 125.
„ „ Berigâ, 111.
„ „ Daba, 109.
„ „ Debebi lil Betan, 125.
„ „ Debebi lil Khoda, 112, 125.
„ „ Dibban, 109.
„ „ Etl, 104.
„ „ Fagir, 121.
„ „ Gerifat, 103.
„ „ Ghalqa, 110.
„ „ Ghusun, 107.
„ „ Gurdi, 83.
„ „ Had (tributary of Wadi Deheis), 93.
„ „ Had (tributary of Wadi Hafafit), 104.
„ „ Had (tributary of Wadi Rahaba), 115.
„ „ Hamamid, 84.
„ „ Hashim (tributary of Wadi Kharit), 83.
„ „ Hashim (tributary of Wadi Garara), 88.
„ „ Hashim (tributary of Wadi Feqoh), 128.
„ „ Hegilig, 107.
„ „ Hireiq, 142.
„ „ Hodeid, 141.
„ „ Hugban, 112.
„ „ Marwa lil Lahami, 108.
„ „ Marwa lil Naait, 110.
„ „ Marwa lil Naait, amphibolite of hill near, 317.
„ „ Nikheil, 114.
„ „ Nilih, 121.
„ „ Reye, 114.
„ „ Ribian, 115.
„ „ Rusheid, 106.
„ „ Sada, 106.
„ „ Selili, 83.
„ „ Seyal (tributary of Wadi Gerf), 81.
„ „ Seyal (tributary of Wadi Naam), 121.
„ „ Sieiyil, 125.
„ Akau, 158.
„ Akwamtra, 156.
„ Amba-ut, 99.
„ „ rock of hill at head of, 285.
„ Anbat, 83.
„ Anfeib, 129.
„ Anfeib el Tawayib, 129.
„ Antar, 87.
„ Aqilhoq, 162, 373.
„ Aqwai, 162, 373.
„ Aqwem, 154.
„ Arais, 121.
„ „ schistose serpentine of, 324.
„ el Arned, 116.
„ Atabi, 99.
„ Atalab, 129.
„ Atluk, 131.
„ Awamtib, 88.
„ Awitla, 147.
„ Baaneit, 138.
„ „ diorite of, 287.
„ Bagharid, 93.
„ Baueiwai, 154.
„ Beida, 132.
„ „ schists of, 342.
„ Belamhandeit, 122.
„ Berendiyeb, 131.
„ Betan, 124.
„ Bint el Feqoh, 93.
„ Bint el Kurdum, 114.
„ Buluk, 113.
„ Buyet, 127.
„ Dabur, 98.
„ Dagalai (tributary of Wadi Timsah), 88.
„ Dagalai lil Rahaba, 115.
„ Dageina, 91.
„ Dauriai, 93.
„ Dehaiartib, 132.
„ Defeit, 92.
„ Deheis, 93.
„ Delawet (tributary of Wadi Seyet), 127.
„ Delawet (tributary of Wadi Hasium), 141.
„ Delawet (tributary of Wadi Um Bishtit), 145.
„ Delowa, 159.
„ Dibag lil Batoga, 111.
„ Dibag lil Kunserob, 111.
„ Dibir, 152.
„ Didaut, 153.
„ Dif, 125.
„ Difoteb, 129.
„ Di-ib, 148.
„ Di-it, 155.
„ Diqdib, 138.
„ Dishlo, 144.
„ Dreb, 139.
„ Duag, 91.
„ el Dub, 117.
„ Durunkat, 104.
„ Dweig, 79.
„ Eberer, 135.
„ Edunqul, 132.
„ Egat (tributary of Wadi Kharit), 83.
„ Egat (tributary of Wadi Alaqi), 91.
„ Egat (tributary of Wadi Betan), 125.
„ Eidab, 108.
„ Eikwan, 155.
„ Eimya, 144.
„ Eirahimib, 129.
„ Elemikan, 84.
„ Enqireidia, 125.
„ Eqaiyib, 148.
„ Erf Um Araka, 121.
„ Faditiai, 129.
„ Fegas, 99.
„ Feqoh, 126.
„ el Fil, 121.
„ Ga-aweit-reb, 377.
„ Gaetri, 104.
„ el Garara, 87.
„ „ dykes of, 272.
„ „ tilted sandstones of, 358.
„ Gelabat Shabai, 126.
„ Gemal, 100.
„ „ pegmatitic granite of, 271.
„ „ diorite-gneiss of, 334.
„ „ olivine-diabase of, 308.
„ Gerf, 81.
„ Ghadir, 99.
„ Ghadrib, 88.
„ Ghuel, 99.
„ el Gihab, 118.
„ Gimal (tributary of Wadi Feqoh), 127.
„ Gumudlum (tributary of Wadi Lahami), 108.
„ Gumudlum (tributary of Wadi Khoda), 113.
„ Guqub, 92.
„ Habliai, 146.
„ Hadelshisheib, 128.
„ Hafafit, 104.
„ Haiyo, 144.
„ Haletiai, 128.
„ Hamata, 107.
„ Hamida (tributary of Wadi Defeit), 93.
„ Hamida (tributary of Wadi Baueiwai), 155.
„ Hamish, 79.
„ Hamsiat, 374.
„ Hangalia, 81.
„ Hankuk, 144.
„ Haratreit, 107.
„ Hareitra, 151.
„ Hashimaiyib, 152.
„ Hasium, 140.
„ Hateib, 92.
„ Hefeifit, 104.
„ Hefeiri (tributary of Wadi Romit), 107.
„ Hefeiri (tributary of Wadi Betan), 125.
„ Helie, 83.
„ Hilgit, 83.
„ Hilgit lil Huluz, 103.
„ Hilwit Hasium, 140.
„ Himeitra, 91.
„ Hindia, 112.
„ Hiteib, 92.
„ Hodein, 115.
„ Hukeib, 375.
„ Huluz, 102.
„ „ basalt of, 312.
„ „ diorite of, 287.
„ „ felsites of, 277, 282.
„ „ olivine-diabase of, 308.
„ Hushenab, 128.
„ Hutit, 115.
„ Ibib, 140.
„ Igli, 98.
„ „ gypseous beds of, 258.
„ Kalalat, 110.
„ „ serpentine of, 323.
„ Kamoyib, 127.
„ Kansisrob, 158.
„ Kharit, 82.
„ Khashab (tributary of Wadi Kharit), 86.
„ Khashab (tributary of Wadi Hodein) 132.
„ Khashir, 107.
„ el Khasiya, 119.
„ el Khisei, 104.
„ el Khiua, 121.
„ Khoda, 111.
„ „ quartz-boss in, 265.
„ Kilanai, 138.
„ Kiraf, 148.
„ Kirir, 91.
„ Kirwau, 143.
„ Kolaiqo (tributary of Wadi Madi), 132.
„ Kolaiqo (to sea), 136.
„ Korbiai, 134.
„ Kreiga, 134.
„ „ calcareous schist of, 349.
„ „ diabase dykes of, 309.
„ „ diorite dyke in, 288.
„ „ diorite-porphyrite dykes in, 293.
„ „ granite of, 269, 271.
„ el Kreim, 87.
„ „ dykes of, 272.
„ „ fault in sandstone in, 358.
„ Krioni, 85.
„ Kunserob, 111.
„ Kwilimandaiyeib, 153.
„ Lahami, 107.
„ Lasewid, 147.
„ Lewewi, 100.
„ Madi, 129.
„ Maghal, 119.
„ Mahali, 103.
„ Malhat, 118.
„ Mantil Hasium, 140.
„ el Marafai, 115.
„ Marasan, 103.
„ Marasani, 85.
„ Mashushenai, 152.
„ Ma-ud, 99.
„ Medarai, 143.
„ Medsus, 83.
„ Megah, 115.
„ Meisah, 146.
„ Meladoyeb, 93.
„ Meneiga, 134.
„ Merau, 91.
„ Merdiyeb, 143.
„ Metawit, 87.
„ Miatit, 154.
„ Miaus, 91.
„ Mikbi, 107.
„ Mindeit, 110.
„ Mistura, 125.
„ Mitatib, 129.
„ el Mukhatatat, 101.
„ Muegil, 116.
„ „ sandstone of, 360.
„ Muelih, 80.
„ „ augite-porphyrite dyke in, 293.
„ „ schists of, 340.
„ el Mukhit, 110.
„ Muqur, 137.
„ „ diorite of, 287.
„ Murra, 109.
„ Naait, 110.
„ Naait, amphibolite near, 317.
„ Na-akreib, 374.
„ Naam, 120.
„ el Nasbia, 101.
„ Natash, 89.
„ Nilateib, 142.
„ el Nom, 116.
„ Nubitra, 154.
„ Nugrus, 105.
„ „ diorite-gneiss of, 334.
„ „ fluidal breccia in, 350.
„ „ muscovite-granite near, 274.
„ Odis, 141.
„ Orga el Atshani, 119.
„ Orga el Rayani, 119.
„ Orgem, 146.
„ Odruk, 142.
„ O Sir Eirab, 159.
„ O Sir Hadal, 156.
„ Qabatit, 163.
„ Qadiloi, 138.
„ Qeirat, 156.
„ Qidmib, 144.
„ Qumad Lim, 150.
„ Qumat Yawab, 375.
„ el Qurat, 152.
„ Radad, 136.
„ Rahaba, 114.
„ Remalib, 128.
„ Romit, 107.
„ Saalek, 117.
„ „ faults in sandstone of, 360.
„ „ fault-breccias near, 351.
„ Sabahia, 99.
„ Safihat, 83.
„ Salalob, 149.
„ Salib el Abiad, 112.
„ „ „ chlorite-schist from, 347.
„ Salib Azrak, 112.
„ el Sania, 116.
„ Sarid, 92.
„ Sarobaiya, 147.
„ Sefent, 108.
„ Seiga, 93.
„ Serimtai, 159.
„ Seyet, 127.
„ Shab, 136.
„ Shabakhit, 88.
„ Shait, 79.
„ Shellal (near Halaib), 162, 373.
„ Shellal el Gharbi, 130.
„ Shellal el Sharqi, 137.
„ el Sheikh, 85.
„ Shendib, 151.
„ Shenshef, 113.
„ „ quartz-schist of, 337.
„ Sherefa el Gharbi, 127.
„ Sherefa el Sharqi, 139.
„ „ „ asbestos of, 330.
„ Shib, 113.
„ Shigeg, 135.
„ Shinai, 140.
„ Shoab, 107.
„ Shut, 112.
„ Siamtit, 156.
„ Sibrit, 82.
„ Sikait, 106.
„ Silsila, 122.
„ „ sandstone of, 360.
„ Sinatib, 131.
„ Sinqinyeib, 152.
„ Soaorib, 144.
„ Sortdau, 128.
„ Sorubiab, 114.
„ Suhin, 92.
„ Sukari, 98.
„ Tarfawi, 103.
„ Tawayib, 127.
„ Ti Ilak, 137.
„ Tikosha, 138.
„ Tikraneib, 142.
„ Timsah, 88.
„ Titai, 114.
„ Todhi, 158.
„ Tugudbaia, 131.
„ Unfagalan, 129.
„ Um el Abbas, 106.
„ „ Abid, 99.
„ „ Akra, 112.
„ „ Arta, 117.
„ „ Bishtit, 145.
„ „ Bisilla, 121.
„ „ Buerat, 114.
„ „ Daba, 83.
„ „ Dafiri, 99.
„ „ Deheisi, 85.
„ „ „ basalt of, 312.
„ „ Derera, 93.
„ „ Eleiga, 125.
„ „ Eshub, 108.
„ „ Etli, 114.
„ „ Gamil, 100.
„ „ Ghobasha, 108.
„ „ Gholqa, 93.
„ „ Goran, 111.
„ „ Gubur, 113.
„ „ Gunud, 108.
„ „ Guruf, 121.
„ „ Hargal, 85.
„ „ „ augite-diorite of, 289.
„ „ Hasidok, 83.
„ „ Hegiligi lil Huluz, 103.
„ „ Heran, 101, 106.
„ „ Hereini, 85.
„ „ Homar, 108.
„ „ Iteili, 104.
„ „ Kabu, 101.
„ „ Karaba (tributary of Wadi Lahami), 108.
„ „ Karaba (tributary of Wadi Salib Azrak), 112.
„ „ Khariga, 98.
„ „ „ serpentine near, 322.
„ „ „ schist of, 349.
„ „ Khuzama, 108.
„ „ Lassaf, 113.
„ „ Maiat, 111.
„ „ Marakh, 88.
„ „ Nasir, 85.
„ „ Reddam, 131.
„ „ Reit, 117.
„ „ Retba, 85.
„ „ el Rid, 88.
„ „ Rishan, 108.
„ „ Saha, 139.
„ „ Seleim, 120.
„ „ Sellim (tributary of Wadi Kharit), 83.
„ „ Sellim (tributary of Wadi Kalalat), 111.
„ „ Sellim lil Mindeit, 110.
„ „ Sellimi, 101.
„ „ Semiuki, 103.
„ „ Sereiha, 85.
„ „ Seyal (tributary of Wadi Gerf), 81.
„ „ Seyal (tributary of Wadi Serimtai), 159.
„ „ Seyal el Foqani, 105.
„ „ Seyal el Tahtani, 105.
„ „ Seyal lil Khoda, 113.
„ „ Sididad, 122.
„ „ Somra, 85.
„ „ Sueh, 101.
„ „ Suerab lil Huluz, 103.
„ „ Sumer, 110.
„ „ Sumur, 116.
„ „ Tawil lil Khoda, 112.
„ „ Tawil lil Shut, 113.
„ „ Tenedba, 120.
„ „ Teneidib, 92.
„ „ el Tiur, 83.
„ „ Tundeba, 99.
„ „ „ calcareous tufa of, 257.
„ Umeiatib, 128.
„ Wadheit, 127.
„ Warabeit, 153.
„ Waseb, 374.
„ Wieqwer, 153.
„ Yahameib, 157.
„ Yameinai, 375.
„ Yoider, 155.
„ Zabara, 99.
Water sources, list of, 242.
„ „ ownership of, 370.
„ supplies, 25, 234.
„ transport of, 242.
Watershed between Nile and Red Sea, 20.
Wehrlites, 319.
Wells, 236.
Wells, analyses of water of, 237.
Wells Mr. J. F., 90.
Wellsted, 6.
Wiekorei, 233.
Wilkinson, 6.
=Z=
Zabara, emerald-mines of, 346.
Zeberged, peridot-mines at, 28.
* * * * *
=GEOGRAPHY AND GEOLOGY OF SOUTH-EASTERN EGYPT.=
BY DR. J. BALL.
* * * * *
=CORRIGENDA.=
* * * * *
Page.
11 line 9 from top, _for_ “Modellin” _read_ “Modellim.”
21 footnote, line 2 from bottom, _for_ “watershed” _read_ “westward.”
24 line 2 from top, _for_ “figures” _read_ “fingers.”
47 in heading of last column of table, _for_ “observed-computed”
_read_ “computed-observed.”
49 line 7 from top, _for_ “area” _read_ “sea.”
49 footnote, line 3 from bottom, _for_ “k = of 0·13” _read_
“k = 0·13.”
49 footnote, bottom line, in the denominator of the fraction, _for_
“2—r” _read_ “2r.”
51 line 12 from bottom, in last column, _for_ “0” _read_ “—.”
52 line 12 from top, in last column, _for_ “0” _read_ “—.”
54 line 12 from top, the latitude of point No. 353 _is_
“23° 47′ 37″” _not_ “23° 47′ 47″.”
57 line 14 from top, _for_ “Fokani” _read_ “Foqani.”
58 line 14 from top, _for_ “Mukur” _read_ “Muqur.”
59 line 9 from bottom, _for_ “Un Rasein” _read_ “Um Rasein.”
60 line 2 from bottom, in last column, _for_ “highest” _read_ “high.”
61 line 3 from top, delete “minor.”
63 line 8 from top, _for_ “G. Di-ib” _read_ “W. Di-ib.”
72 last line, _for_ “as” _read_ “if.”
75 line 10 from top, _for_ “added of” _read_ “added to.”
76 the observed compass-variation near Halaib Fort _was_ “2° 18′,”
_not_ “3° 18′,” and in the observed variation at Helwân the
figures given as seconds should be decimals of a minute.
77 the yearly decrease of declination (in three places) _should be_
6′·3 _instead of_ “6′ 3″.”
82 line 22 from top, _for_ “Wani” _read_ “Wadi.”
83 line 18 from top, _for_ “Um Selim” _read_ “Um Sellim.”
88 line 11 from top, _for_ “Feleiti” _read_ “Felieiti.”
98 line 2 from top, _for_ “Serimtay” _read_ “Serimtai.”
99 lines 4 and 7 from bottom, _for_ “Sabaia” _read_ “Sabahia.”
101 line 25 from top, _for_ “Um Heram” _read_ “Um Heran.”
103 line 9 from top, _for_ “The one” _read_ “The upper one.”
104 line 17 from top, _for_ “heap” _read_ “head.”
105 line 11 from top, _for_ “42° 34′” _read_ “24° 34′.”
109 line 18 from top, _for_ “35° 47′ 10″” _read_ “35° 47′ 13″.”
118 line 11 from bottom, _for_ “curved” _read_ “carved.”
144 lines 10 and 22 _for_ “Meisa” _read_ “Meisah.”
145 top line, _for_ “Meisan” _read_ “Meisah.”
152 line 8 from top, _for_ “Akwantra” _read_ “Akwamtra.”
153 line 8 from top, _for_ “aad” _read_ “and.”
159 line 5 from top, _for_ “Mikreiba” _read_ “Mikeriba.”
159 last line, _for_ “22° 13′ 24″” _read_ “22° 13′ 25″.”
159 last line and footnote, _for_ “Qosier” _read_ “Qoseir.”
160 top line, _for_ “36° 38′ 54″” _read_ “36° 38′ 56″.”
162 line 7 from top, _for_ “to” _read_ “or.”
162 line 5 from bottom, _for_ “Qubit” _read_ “Qubet.”
167 line 10 from top, _for_ “1099 metres” _read_ “1199 metres.”
167 line 15 from bottom, _for_ “Krug” _read_ “Khrug.”
173 line 8 from top, _for_ “Itelma” _read_ “Iteima.”
173 line 10 from bottom, _for_ “34° 44′ 35″” _read_ “34° 41′ 35″.”
176 line 4 from top, _for_ “24° 14′ 44″” _read_ “24° 14′ 41″.”
183 line 4 from bottom, _for_ “Mukhtatat” _read_ “Mukhatatat.”
186 last line, _for_ “east” _read_ “west.”
188 line 9 from top, _for_ “24° 54′ 18″” _read_ “24° 54′ 14″.”
188 footnote, _for_ “23° 57′ 67″” _read_ “23° 57′ 46″.”
189 line 8 from top, _delete_ “respectively.”
194 line 9 from bottom, _for_ “these” _read_ “there.”
204 line 16 from top, _for_ “western” _read_ “southern”
206 line 13 from bottom, _for_ “34° 50′ 49″” _read_ “34° 56′ 49″.”
211 line 12 from bottom, _for_ “which” _read_ “while.”
212 line 20 from top, _for_ “Um Rassin” _read_ “Um Rasein.”
213 line 14 from bottom, _for_ “Kirwaw” _read_ “Kirwau.”
223 line 11 from top, _for_ “exit” _read_ “exist.”
223 line 2 from bottom, _for_ “Hashushenai” _read_ “Mashushenai.”
224 line 18 from top, _for_ “jugged” _read_ “rugged.”
228 last line, _for_ “masses” _read_ “mosses.”
233 line 3 from bottom, _for_ “in” _read_ “on.”
235 footnote, _for_ “Megwal” _read_ “Megwel.”
238 line 9 from top, _for_ “aad” _read_ “and.”
242 line 3 from bottom, _before_ “vary” _insert_ “they.”
245 top line, _for_ “Wadi Sikait” _read_ “Wadi Shait.”
246 the latitude of Galt el Aguz _is_ “23° 32′ 30″” _not_
“23° 31′ 30″.”
248 the latitude of Bir Muqur _is_ “22° 42′ 26″” _not_ “22° 41′ 26″.”
253 top line, _for_ “Mesah” _read_ “Meisah.”
259 line 17 from bottom, _for_ “Dib” _read_ “Dif.”
263 line 8 from top, _for_ “section” _read_ “sections.”
273 top line, _for_ “sprinking” _read_ “sprinkling.”
278 last line, _for_ “XXI” _read_ “XXII.”
304 line 11 from bottom, _for_ “pale” _read_ “free.”
304 line 9 from bottom, _for_ “forms” _read_ “form.”
306 line 7 from top, _for_ “44°” _read_ “34°.”
310 line 11 from top, _for_ “dolorite” _read_ “dolerite.”
317 in the description of the figure, insert the word “to” between
“altering” and “granular.”
333 line 2 from top, _for_ “Modergeg” _read_ “Mudergeg.”
339 line 13 from top, _for_ “resemblance” _read_ “semblance.”
341 line 14 from top, _for_ “ericite” _read_ “sericite.”
342 line 18 from top, _for_ “dentritic” _read_ “dendritic.”
342 line 5 from bottom, _for_ “on” _read_ “in.”
346 line 8 from top, _for_ “ancient” _read_ “ancients.”
351 line 13 from top, _for_ “p. 441” _read_ “p. 341.”
353 line 12 from top, _for_ “Magnetite” _read_ “Magnesite.”
358 line 4 from top, _for_ “XV” _read_ “XX.”
360 line 16 from top, _for_ “XX” _read_ “XV.”
366 footnote, line 5 from bottom, _for_ “Megwell” _read_ “Megwel.”
367 footnote, line 3 from bottom, _for_ “or” _read_ “of.”
387 line 18 from top, _for_ “Mitab” _read_ “Mitba.”
390 line 14 from bottom, _for_ “Balamhandeit” _read_ “Belamhandeit.”
392 line 18 from top, _for_ “Mokhatatat” _read_ “Mukhatatat.”
392 line 25 from top, _for_ “Kukhit” _read_ “Mukhit.”
393 second column, line 16 from top, _for_ “Kalabat” _read_ “Kalalat.”
394 last line, _for_ “Zebeged” _read_ “Zeberged.”
* * * * *
SHORT CATALOGUE
OF THE
=MAPS, PLANS, AND PUBLICATIONS=
ISSUED BY THE
SURVEY DEPARTMENT, MINISTRY OF FINANCE, EGYPT.
* * * * *
=MAPS AND PLANS.=
* * * * *
The following is a general list of the maps and plans offered for
sale by the Survey Department. A booklet giving details of all sheets
printed may be obtained free, on application either personally or by
letter at the Headquarters of the Department, Gîza (Mudiria), or at the
Geological Museum, Public Works Ministry Gardens, Cairo, where all maps
and plans are for sale, or through any bookseller.
Except where specially stated, the price of each map-sheet is 50
milliemes on paper, and 65 milliemes on cloth, and they are sent post
free by the Department.
The reference marks denote: (*) map is in Arabic only; (†) map is in
English only; (*†) map bears place-names both in Arabic and English;
(*) (†) map can be obtained either in Arabic or English.
=Town Maps.=
The following list gives particulars of the maps published. The map of
Alexandria, on the scale of 1:1,000, will be completed during 1913. The
survey of Cairo on the scale of 1:1,000 is in progress.
Cairo (*†), 28 sheets, scale 1:1,000 (already printed).
Alexandria (*†), 200 sheets, scale 1:1,000.
Alexandria (*) (†), 15 sheets, scale 1:5,000.
General map of Alexandria Municipality (French and Arabic), 10 sheets
scale 1:6,000.
Mit Ghamr (*†), 4 sheets, scale 1:1,000.
Mansûra (*†), 16 sheets, scale 1:1,000.
Suez (*†), 20 sheets, scale 1:1,000.
Suez (*†), 1 sheet, scale 1:2,500.
Sohag (*†), 6 sheets, 1:1,000.
Tanta (*†), 15 sheets, scale 1:1,000.
Girga (*†), 6 sheets, scale 1:1,000.
Aswân (*†), 23 sheets, scale 1:1,000.
Port Said (in French), 1 sheet, scale 1:5,000.
Zagazig (*†), 20 sheets, scale 1:1,000.
Damanhûr (*†), 14 sheets, scale 1:1,000.
Benha (*†), 25 sheets, scale 1:1,000.
Fayûm (*†), 26 sheets in all, of which 8 are printed, scale 1:1,000.
=Cadastral Maps.=
These are maps of the villages showing each _hod_ and plot of land.
They are printed in Arabic only. In ordering, the name of the village
and the numbers of _hod_ and plot should be given. The following list
gives the particulars of the maps for each mudiria (province):—
Beheira mudiria (*), 3,300 sheets, under survey, scale 1:2,500.
Gharbîa mudiria (*), 3,460 sheets, scale 1:4,000 and 1: 2,500.
Daqahlîa mudiria (*), 2,237 sheets, scale 1:2,500.
Sharqîa mudiria (*), 2,974 sheets, scale 1:2,500.
Menufîa mudiria (*), 2,173 sheets, scale 1:4,000 and 1:2,500.
Qaliubîa mudiria (*), 778 sheets, scale 1:2,500.
Gîza mudiria (*), 766 sheets, scale 1:4,000.
Fayûm mudiria (*), 2,263 sheets, scale 1:2,500.
Beni Suef mudiria (*), 942 sheets, scale 1:2,500.
Minia mudiria (*), 1,635 sheets, scale 1:2,500.
Assiût mudiria, including Kharga Oasis (*), 2,273 sheets,
scale 1:2,500.
Girga mudiria (*), 1,313 sheets, scale 1:2,500.
Qena mudiria (*), 1,568 sheets, scale 1:2,500.
Aswân mudiria (*), 1,076 sheets, scale 1:2,500.
=Topographical Maps.=
Scale 1:10,000 (10 cm. = 1 kilometre; 6·3 inches = 1 mile).—The names
on these maps are in most cases in Arabic and English. The following
table shows the number of sheets published:—
Beheira mudiria (*), 260 sheets (old series).
Beheira mudiria (*†), 53 sheets already printed, scale 1:10,000
(new series).
Gharbîa mudiria (*†), 157 sheets (old series).
Gharbîa mudiria (*†), 83 sheets already printed, scale 1:10,000
(new series).
Sharqîa mudiria (*†), 53 sheets.
Daqahlîa mudiria (*†), 11 sheets.
Menufîa mudiria (*†), 73 sheets.
Qaliubîa mudiria (*†), 65 sheets.
Gîza mudiria (*†), 90 sheets (first edition).
Gîza mudiria (*†), 13 sheets already printed, scale 1:10,000
(second edition).
Fayûm mudiria (*†), 126 sheets.
Beni Suef mudiria (*†), 21 sheets.
Assiût mudiria, including Kharga Oasis (*†), 72 sheets.
Aswân mudiria (*†), 63 sheets.
Aswân or First Cataract (†), 6 sheets.
The Nile Valley from Aswân to Korosko (†), 36 sheets (paper only,
25 milliemes each).
Scale 1:25,000 (4 cm. = 1 kilometre; 2·5 inches = 1 mile).—A
provisional map of Northern Gharbîa has been published on this scale,
pending the publication of the 1:10,000 sheets of this area. There are
91 sheets.
Scale 1:50,000 (2 cm. = 1 kilometre; 1·3 inches = 1 mile).—These maps
are printed in three colours. Names are given in English, and as a
rule in Arabic as well. This series is completed for the whole of the
cultivated area of the Nile Valley and Delta. There are 164 sheets.
A second and revised edition is being published gradually; it will
include the sheets of certain outlying areas such as Lake Menzala, Suez
Canal, Wadi Natrun, etc., which, owing to lack of time or opportunity,
have either not been published or published from defective data.
Scale 1:250,000 (1 cm. = 5 kilometres; 1 inch = 8 miles).—The
preparation of the four sheets of this series, embracing the area of
the Delta, is now being proceeded with. The two western sheets are
printed in English only and the remaining two eastern sheets will be
published by the end of the year (1912). Price, 100 milliemes per sheet.
Scale 1:1,000,000 (1 cm. = 10 kilometres; 1 inch = 16 miles).—The
six sheets of this map, covering the whole of Egypt, have now been
published. The names are in English. The price of each sheet is 50 and
65 milliemes for paper and cloth editions respectively, or the whole
can be obtained mounted on cloth, varnished, and fitted with rollers
for 550 milliemes.
=Special Maps on Various Scales.=
Map of Cairo and Environs (*), 1 sheet, scale 1:100,000. Price, 100
milliemes on ordinary paper or 150 mounted and folded for the use of
tourists.
Map of the Delta (*) (†), 4 sheets, scale 1:200,000. Price, 75
milliemes per sheet, or the complete map mounted on cloth, varnished,
and fitted with rollers, 700 milliemes.
Map of the Delta (†), 4 sheets, scale 1:200,000, showing telephone
lines. Price as the one above.
Lower Egypt and the Fayûm, 1904 (latest edition) (†), 1 sheet,
scale 1:500,000.
Lower Egypt, showing lines of communication (†), 1 sheet,
scale 1:500,000.
Map of Menufîa mudiria (*), scale 1:50,000, in two sheets mounted
together on cloth and fitted with rollers. Price, 850 milliemes.
Northern Gharbîa (*†), 1 sheet, scale 1:200,000.
Kharga Oasis (†), 1 sheet, scale 1:500,000.
Dakhla Oasis (†), 1 sheet, scale 1:500,000.
Baharia Oasis (†), 1 sheet, scale 1:500,000.
Farafra and Iddalia Oases (†), 1 sheet, scale 1:500,000.
Provisional map of the Eastern Desert of Egypt, East Qena-Aswân
to Red Sea (†), 20 sheets, scale 1:100,000.
Provisional map of the Eastern Desert of Egypt, between Qus, Sayala,
and Red Sea (†), 2 sheets, scale 1:500,000.
Provisional map of a part of the Eastern Desert Oilfield (†),
1 sheet, scale 1:100,000. Price, 100 milliemes on paper and
150 milliemes on cloth.
Provisional map of a part of the Eastern Desert Oilfield, showing
registered prospecting areas (†), 1 sheet, scale 1:100,000. Price,
100 milliemes on paper and 150 milliemes on cloth.
Red Sea and Sinai Oilfield, showing registered prospecting areas (†),
1 sheet, scale 1:316,800. Price, 100 milliemes on paper and
150 milliemes on cloth.
Jemsa Oil Zone (†), 1 sheet, scale 1:75,000 and 1:250,000. Price,
50 milliemes.
Mersa Matruh chart (†), 1 sheet, scale 1:4,500.
Mersa Matruh topographical map (†), 1 sheet, scale 1:10,000.
Mersa Matruh and Ras Allam Rum (†), 2 sheets, scale 1:25,000.
Aqaba-Rafa, 1906 (*†), 3 sheets, scale 1:100,000.
Aqaba-Rafa, 1906 (*) (†), 1 sheet, scale 1:500,000 (paper,
25 milliemes; cloth, 40 milliemes).
The Nile Valley from Aswân to Sudan boundary (†), 1 sheet,
scale 1:250,000.
Port d’Alexandrie (French), 3 sheets, scale 1:4,000.
=ATLASES AND SCHOOL-MAPS.=
* * * * *
The price of the school-maps, printed in colours, mounted on cloth,
varnished, and fitted on rollers, is 700 milliemes per copy, except the
Maps of the Mediterranean Basin and of the Ottoman Empire which are 500
milliemes per copy. The price of each part of the Atlas of the World,
published separately, will be 200 milliemes.
=Atlases= (published in Arabic only).
1. Elementary Atlas of Egypt, price per copy 50 mills.
2. Atlas of the World, Part I „ „ 200 „
Contains the following maps: Egypt, the Anglo-Egyptian Sudan, Africa
Political, Africa Physical, eight inset maps of Africa, Asia Political,
Asia Physical, The Ottoman Empire and neighbouring countries, and
Europe Political.
SCHOOL-MAPS.
--+-------------------------------+-----------+---------+-----------
| TITLE. | SCALE. |LANGUAGE.| SIZE.
+-------------------------------+-----------+---------+-----------
| | | | metres.
| | | |
1|Lower Egypt |1: 200,000| Arabic |1·90 × 1·78
| | | |
2| „ „ |1: 200,000| English |1·90 × 1·78
| | | |
3|Orographical Map of the Nile |1:2,500,000| Arabic |1·35 × 1·75
|Basin | | |
| | | |
4| „ „ „ „ |1:2,500,000| English |1·35 × 1·75
| | | |
5|Political Map of Egypt |1: 750,000| „ |1·75 × 1·75
| | | |
6| „ „ „ |1: 750,000| Arabic |1·75 × 1·75
| | | |
7|Political Map of Africa |1:6,000,000| „ |1·75 × 1·85
| | | |
8|Physical Map of Africa |1:6,000,000| „ |1·75 × 1·85
| | | |
9|Political Map of Asia |1:6,000,000| „ |2·05 × 1·85
| | | |
10|Physical Map of Asia |1:6,000,000| „ |2·05 × 1·85
| | | |
11|Map of Western Europe |1:1,500,000| „ |2·25 × 1·85
| | | |
12|Map of the Mediterranean Basin |1:3,000,000| „ |1·80 × 1·20
| | | |
13|Political Map of Europe |1:3,000,000| „ |2·25 × 1·85
| | | |
14|Physical Map of Europe |1:3,000,000| „ |2·25 × 1·85
| | | |
15|The World on Mercator’s | — | „ |2·05 × 1·85
|Projection | | |
| | | |
16|Western Hemisphere | — | „ |1·65 × 1·80
| | | |
17|Eastern Hemisphere | — | „ |1·65 × 1·80
| | | |
18|Physical Map of the British |1: 750,000| „ |1·75 × 1·75
|Isles | | |
| | | |
19|Political Map of North America |1:6,000,000| „ |2·05 × 1·85
| | | |
20|Physical Map of North America |1:6,000,000| „ |2·05 × 1·85
| | | |
21|Political Map of South America |1:6,000,000| „ |2·05 × 1·85
| | | |
22|Physical Map of South America |1:6,000,000| „ |2·05 × 1·85
| | | |
23|Political Map of Australia |1:5,000,000| „ |2·05 × 1·85
| | | |
24|Physical Map of the Basin of | — | „ |2·05 × 1·85
|Pacific Ocean | | |
|_(This map shows the new Panama| | |
|Canal and its relations to the | | |
|Pacific ports)._ | | |
--+-------------------------------+-----------+---------+-----------
The following Atlases and maps are in preparation, and will be
published during 1913:—
=Atlases= (published in Arabic only).
1. The Atlas of the World, Part II, will be published in September
1913, and will contain the following maps: 4 inset maps of Asia, Europe
Physical, North Central Africa showing the Basin of the Nile, Lower
Egypt. The World on Mercator’s Projection, North America Political,
North America Physical, South America Political, South America Physical.
2. The Atlas of the World, Part III, is in preparation and will be
published in 1914.
SCHOOL-MAPS.
--+-------------------------------+-----------+---------+-----------
| TITLE. | SCALE. |LANGUAGE.| SIZE.
+-------------------------------+-----------+---------+-----------
1|The Ottoman Empire and | | |
|Neighbouring Countries |1:5,000.000| Arabic |1·35 × 1·20
--+-------------------------------+-----------+---------+-----------
=Geological Maps.=
Geological map of Egypt, scale 1:1,000,000. English. Six sheets, 70 ×
58 cm. Price, 100 milliemes per sheet. Complete map, mounted on cloth,
varnished, and fitted with rollers, 850 milliemes.
Geological map of Egypt, scale 1:2,000,000. English. One sheet, 68½
× 67 cm. Price, 200 milliemes on paper, and 300 milliemes mounted on
cloth and fitted with rollers.
A number of maps have been published in the various Geological reports.
Further information may be obtained under the respective headings in
the list of Geological Reports, pp. V and VI.
=PUBLICATIONS.=
* * * * *
The following is a general list of the publications of the Survey
Department, and a few others which are for sale at the Headquarters of
the Department, Gîza (Mudiria), and at the Geological Museum, Public
Works Ministry Gardens, Cairo. A booklet giving full details can be
obtained, on application either personally or by letter.
Except where specially stated, the publications are 8vo, and in
English, and are supplied post free by the Department. They can also be
obtained through any bookseller.
=Archæology.=
ARCHÆOLOGICAL SURVEY OF NUBIA.
BULLETIN 1.—Dealing with the work (archæological and anatomical) from
September 20 to November 30, 1907. English. 39 pp., 27 illustrations.
(Out of print.)
BULLETIN 2.—Dealing with the work (archæological and anatomical) from
December 1, 1907, to March 31, 1908. English. 69 pp., 52 illustrations.
Price, 100 milliemes.
BULLETIN 3.—Dealing with the work (archæological and anatomical) from
October 1 to December 31, 1908. English. 52 pp., 5 illustrations.
Price, 100 milliemes.
BULLETIN 4.—Dealing with the work (archæological and anatomical) from
January 1 to March 31, 1909. English. 28 pp., 2 illustrations. Price,
100 milliemes.
BULLETIN 5.—Dealing with the work (archæological and anatomical) from
October 1 to December 31, 1909. English. 35 pp., 5 illustrations.
Price, 100 milliemes.
BULLETIN 6.—Dealing with the work (archæological and anatomical) from
January 1 to April 15, 1910. English. 30 pp., 8 illustrations. Price,
100 milliemes.
BULLETIN 7.—Dealing with the work (archæological and anatomical)
from November 1, 1910, to February 28, 1911. English. 19 pp., 3
illustrations. Price, 100 milliemes.
ANNUAL REPORT OF THE ARCHÆOLOGICAL SURVEY OF NUBIA, SEASON 1907-8. VOL.
I: by GEORGE A. REISNER. Price, with volume of plates, L.E. 2.
ANNUAL REPORT OF THE ARCHÆOLOGICAL SURVEY OF NUBIA, SEASON 1907-8. VOL.
II: Report on the Human Remains, by Dr. G. ELLIOT SMITH, F.R.S., and
Dr. F. WOOD JONES. Price, with volume of plates, L.E. 2.
PHILÆ—REPORT ON THE ISLAND AND TEMPLES OF, by CAPT. H. G. LYONS,
with introductory note by W. E. GARSTIN. 1896. English. 67 pp., 78
illustrations. (Out of print.)
PHILÆ—REPORT ON THE ISLAND AND TEMPLES OF, by CAPT. H. G. LYONS. 1908.
English. 4to, 32 pp., 14 illustrations. Price, 200 milliemes.
=Geography.=
RIVER NILE AND ITS BASIN—PHYSIOGRAPHY OF THE, by CAPT. H. G. LYONS.
1906. 411 pp., 14 maps, 34 illustrations. Price, 400 milliemes.
TURCO-EGYPTIAN BOUNDARY BETWEEN THE VILAYET OF THE HEJAZ AND THE
PENINSULA OF SINAI—THE DELIMITATION OF THE, by E. B. H. WADE, together
with additions by B. F. E. KEELING and J. I. CRAIG. 1906. (Survey
Department Paper, No. 4). 89 pp., 2 maps. Price, 150 milliemes. _See
also_ Geology.
=Geology.=
ABU ROASH, NEAR THE PYRAMIDS OF GÎZA—CRETACEOUS REGION OF, by H. J. L.
BEADNELL. 1902. 48 pp., 2 maps, 19 illust. Price, 200 milliemes.
ARSINOITHERIUM ZITTELI (Beadnell), FROM THE UPPER EOCENE STRATA OF
EGYPT—PRELIMINARY NOTE ON, by H. J. L. BEADNELL. 1902. 4 pp., 6
illustrations. Price, 50 milliemes.
ASWÂN (FIRST) CATARACT OF THE NILE—DESCRIPTION OF, by DR. BALL. 1907
121 pp., 5 maps, 28 illustrations. Price, 200 milliemes.
BAHARIA OASIS, ITS TOPOGRAPHY AND GEOLOGY, by DR. BALL and H. J. L.
BEADNELL. 1903. 84 pp., 8 maps, 2 illust. Price, 200 milliemes.
BLACKENED ROCKS OF THE NILE CATARACTS AND OF THE EGYPTIAN DESERTS, by
A. LUCAS. 1905. 58 pp. Price, 100 milliemes.
BUILDING STONES IN EGYPT—DISINTEGRATION OF, by A. LUCAS. 1902. 17 pp.
Price, 75 milliemes.
BUILDING STONES OF CAIRO NEIGHBOURHOOD AND UPPER EGYPT, by DR. HUME.
1909. 92 pp., 9 illustrations. Price, 150 milliemes. Survey Department
Paper, No. 16.
CAIRO AND SUEZ—TOPOGRAPHY AND GEOLOGY OF THE DISTRICT BETWEEN, by T.
BARRON. 1907. 133 pp., 2 maps, 14 illustrations. Price, 200 milliemes.
CATALOGUE OF THE GEOLOGICAL MUSEUM, CAIRO, by DR. HUME. 1905. 37 pp.
Price, 25 milliemes.
DAKHLA OASIS, ITS TOPOGRAPHY AND GEOLOGY, by H. J. L. BEADNELL. 1901.
107 pp., 9 maps, 7 illustrations. Price, 200 milliemes.
EASTERN DESERT OF EGYPT, CENTRAL PORTION—TOPOGRAPHY AND GEOLOGY OF, by
T. BARRON and DR. HUME. 1902. 331 pp., 10 maps, 30 illust. Price, 400
milliemes.
EASTERN DESERT OF EGYPT, BETWEEN LATITUDES 22° AND 25° N.—PRELIMINARY
REPORT ON GEOLOGY OF, by DR. HUME. 1907. 72 pp., 4 maps, 5 illust.
Price, 150 milliemes. Survey Department Paper, No. 1.
EXPLANATORY NOTES TO ACCOMPANY THE GEOLOGICAL MAP OF EGYPT (map
mentioned on page iv), by DR. W. F. HUME. D.SC., F.G.S., F.R.S.E.
Price, 100 milliemes.
FARAFRA OASIS, ITS TOPOGRAPHY AND GEOLOGY, by H. J. L. BEADNELL. 1901.
39 pp., 8 maps. Price, 150 milliemes.
FAYÛM PROVINCE OF EGYPT—TOPOGRAPHY AND GEOLOGY OF, by H. J. L.
BEADNELL. 1905. 101 pp., 2 maps, 22 illustrations. Price, 300 milliemes.
FORÊTS PÉTRIFIÉES DES DÉSERTS DE L’EGYPTE—NOTE SUR L’ÂGE DES, par M. R.
FOURTEAU. 1898. French. 8 pp. (Out of print.)
IRON ORES IN EGYPT—DISTRIBUTION OF, by DR. HUME. 1909. 16 pp., 1 map.
Price, 50 milliemes. Survey Department Paper, No. 20.
JEBEL GARRA AND THE OASIS OF KURKUR—TOPOGRAPHICAL AND GEOLOGICAL
RESULTS OF A RECONNAISSANCE-SURVEY OF, by DR. BALL. 1902. 40 pp., 2
maps, 5 illustrations. Price, 150 milliemes.
KHARGA OASIS, ITS TOPOGRAPHY AND GEOLOGY, by DR. BALL. 1900. 116 pp.,
19 maps, 16 illustrations. Price, 250 milliemes.
MAMMALS—PRELIMINARY NOTE ON SOME NEW—FROM THE UPPER EOCENE OF THE
FAYÛM, EGYPT, by C. W. ANDREWS and H. J. L. BEADNELL. 1902. 9 pp., 4
illustrations. Price, 100 milliemes.
PÉTROLE DE LA MER ROUGE—RAPPORT SUR LES RECHERCHES DU, par J. BAROIS.
1885. French. 16 pp., 1 map, 10 illustrations. Price, 100 milliemes.
PETROLEUM DISTRICTS SITUATED ON THE RED SEA COAST—REPORT ON, by COL. C.
E. STEWART. 1888. 25 pp. Price, 100 milliemes.
PETROLEUM INDUSTRY AT BAKU—SKETCH REPORT OF, by J. H. TREVITHICK. May,
1886. 22 pp. Price, 100 milliemes.
PHOSPHATE DEPOSITS OF EGYPT, by SURVEY DEPARTMENT. 2nd edition, 1905.
35 pp., 3 maps. Price, 50 milliemes.
PRINCIPLES AND OBJECTS OF GEOLOGY, WITH SPECIAL REFERENCE TO THE
GEOLOGY OF EGYPT, by W. F. HUME. 25 pp., 8 illustrations. Price, 50
milliemes.
SINAI PENINSULA (SOUTH-EASTERN PORTION)—TOPOGRAPHY AND GEOLOGY OF, by
DR. HUME. 1906. 280 pp., 5 maps, 23 illustrations. Price, 300 milliemes.
SINAI PENINSULA (WESTERN PORTION)—TOPOGRAPHY AND GEOLOGY OF, by T.
BARRON. 1907. 241 pp., 2 maps, 13 illustrations. Price, 300 milliemes.
SOIL AND WATER OF THE FAYÛM PROVINCE—PRELIMINARY INVESTIGATION OF, by
A. LUCAS. 1902. 17 pp. Price, 75 milliemes.
SOIL AND WATER OF THE WADI TUMILAT LANDS UNDER RECLAMATION, by A.
LUCAS. 1903. 26 pp., 1 map, 5 illustrations. Price, 100 milliemes.
SUBSOIL WATER IN LOWER EGYPT—PRELIMINARY NOTE ON THE, by H. T. FERRAR,
M.A., F.G.S. 1910. 16 pp., 3 illustrations. Price, 50 milliemes.
THE MOVEMENTS OF THE SUBSOIL WATER IN UPPER EGYPT, by H. T. FERRAR,
M.A., F.G.S. Survey Department Paper, No. 19. English. 74 pp., 32
illustrations, and 16 maps. Price, 150 milliemes.
TERTIARY VERTEBRATA OF THE FAYÛM, EGYPT—DESCRIPTIVE CATALOGUE OF, by C.
W. ANDREWS. 1906. 319 pp., 124 illustrations.
TORTOISE-LAND—FROM THE UPPER EOCENE OF THE FAYÛM, EGYPT—PRELIMINARY
NOTICE OF, by C. W. ANDREWS and H. J. L. BEADNELL. 1903. 11 pp., 3
illustrations. Price, 50 milliemes.
=Meteorology.=
DAILY WEATHER REPORT.—Issued daily by the Survey Department. Contains
the readings taken at 29 stations in Egypt and the Sudan, and five
stations in Southern Europe, with a map showing the distribution of
pressure. Post free, 200 milliemes quarterly, including short monthly
summary.
SUMMARY OF THE WEATHER IN EGYPT, THE SUDAN, AND THE SURROUNDING REGION.
Monthly.—Contains a brief report on the weather for the month, with
maps showing the pressure-distribution for each day. Price, post free,
300 milliemes per annum.
ANNUAL METEOROLOGICAL REPORT.— Contains all the meteorological readings
made during the year in Egypt and the Sudan. Also the readings of the
various Nile gauges.
Years 1898-1899, 1900, 1901, 1902, 1903 Price, 250 mill. each.
Years 1904, 1905 (in two parts: Part I,
containing the readings taken at Helwân
Observatory; Part II, containing the
readings for the rest of Egypt and the
Sudan) Price, 100 mill. each part.
Year 1906 (Part I, Helwân) Price, 100 mill.
Year 1906 (Part II, Rest of Egypt
and the Sudan) Price, 150 mill.
Year 1907 (Parts I and II) Price, 150 mill. each part.
Year 1908 (Parts I and II) Price, 150 mill. each part.
Year 1909 (Parts I and II) Price, 150 mill. each part.
=Nile Flood.=
MEASUREMENT OF THE VOLUMES DISCHARGED BY THE NILE DURING 1905 AND 1906,
by E. M. DOWSON; WITH A NOTE ON RATING FORMULÆ FOR CURRENT-METERS, by
J. I. CRAIG. Survey Department Paper, No. 11. 82 pp., 6 illustrations.
Price, 100 milliemes.
RAINS OF THE NILE BASIN:—
In 1904, by CAPT. H. G. LYONS. 25 pp., 1 map, 5 illustrations. Price,
50 milliemes.
In 1905, by CAPT. H. G. LYONS. 40 pp., 4 maps, 5 illustrations. Price,
50 milliemes.
RAINS OF THE NILE BASIN AND THE NILE FLOOD:—
In 1906, by CAPT. H. G. LYONS. (Survey Department Paper, No. 2).
70 pp., 5 maps, 11 illustrations. Price, 100 milliemes.
In 1907, by CAPT. H. G. LYONS. (Survey Department Paper, No. 9).
50 pp., 1 map, 11 illustrations. Price, 100 milliemes.
In 1908, by CAPT. H. G. LYONS. (Survey Department Paper, No. 14).
69 pp., 1 map, 8 illustrations. Price, 100 milliemes.
In 1909, by J. I. CRAIG. (Survey Department Paper, No. 17). 55 pp.,
1 map, 8 illustrations. Price, 100 milliemes.
In 1910, by J. I. CRAIG. (Survey Department Paper, No, 26). 109 pp.,
12 illustrations. Price, 100 milliemes.
=Special Papers on Meteorology and Astronomy.=
ATMOSPHERIC ELECTRICITY-DISCUSSION OF THE OBSERVATIONS ON—AT HELWÂN
OBSERVATORY, FROM MARCH 1906 TO FEBRUARY 1908, by H. E. HURST. (Survey
Department Paper, No. 10). 65 pp., 2 maps, 8 illustrations. Price, 100
milliemes.
CLIMATE OF ABBASSIA, NEAR CAIRO, by B. F. E. KEELING. (Survey
Department Paper, No. 3). 1907. 61 pp., 1 map, 7 illustrations. Price,
100 milliemes.
EVAPORATION IN EGYPT AND THE SUDAN, by B. F. E. KEELING. (Survey
Department Paper, No. 15). 1909. 29 pp., 1 illustration. Price, 100
milliemes.
METEORITE OF NAKHLA EL BAHARIA, by JOHN BALL. (Survey Department Paper,
No. 25). 22 pp., 3 illustrations. Price, 50 milliemes.
OBSERVATIONS OF HALLEY’S COMET MADE AT THE KHEDIVIAL OBSERVATORY,
HELWÂN, by H. KNOX SHAW. (Survey Department Paper, No. 23). 18 pp., 56
illustrations. Price, 50 milliemes.
PLATINUM-RESISTANCE THERMOMETERS—REPORT ON THE USE OF—IN DETERMINING
THE TEMPERATURE OF THE AIR AT THE HELWÂN OBSERVATORY, by E. B. H. WADE.
1905. 20 pp., 5 illustrations. Price, 50 milliemes.
=Surveying.=
ALTITUDES—THE DETERMINATION OF—BY LEVELLING, by E. M. DOWSON.
(Technical Lecture). 1908. 23 pp., 6 illustrations. Price, 50 milliemes.
CADASTRAL SURVEY OF EGYPT, 1892-1907, by CAPT. H. G. LYONS. 1908. 421
pp., 30 maps, 16 illustrations. Price, 400 milliemes.
CADASTRAL SURVEY OF EGYPT—COMPARISON OF—WITH THOSE OF SOME EUROPEAN
COUNTRIES, by CAPT. H. G. LYONS. (Technical Lecture). 1909. 24 pp., 8
maps. Price, 50 milliemes.
ERRORS OF OBSERVATION, by T. L. BENNETT. (Technical Lecture). 1908. 27
pp., 3 illustrations. Price, 50 milliemes.
LONGITUDE—DETERMINATION OF, by E. B. H. WADE. (Technical Lecture).
1908. 39 pp., 2 maps, 1 illustration. Price, 50 milliemes.
LONGITUDES—A FIELD METHOD OF DETERMINING—BY OBSERVATIONS OF THE MOON,
by E. B. H. WADE. (Survey Department Paper, No. 5). 1907. 47 pp., 9
illustrations. Price, 100 milliemes.
MAP-PROJECTIONS, by J. I. CRAIG. (Technical Lecture). 1909. 25 pp., 1
map, 25 illustrations. Price, 50 milliemes.
MAP-PROJECTIONS—THE THEORY OF—WITH SPECIAL REFERENCE TO THE PROJECTIONS
USED IN THE SURVEY DEPARTMENT, by J. I. CRAIG, F.R.S.E. (Survey
Department Paper, No. 13). 1910. 77 pp., illustrated. Price, 200
milliemes.
NEW METHOD OF COAST SURVEYING, by JOHN BALL. (Survey Department Paper,
No. 21). 46 pp., 7 illustrations. Price, 100 milliemes.
RELIEF ON MAPS—THE REPRESENTATION OF, by CAPT. H. G. LYONS. (Technical
Lecture). 1909. 19 pp., 5 maps. Price, 50 milliemes.
SOME GENERAL PRINCIPLES OF SURVEYING, by J. I. CRAIG. (Technical
Lecture). 1910. 20 pp., 8 illustrations. Price, 50 milliemes.
=Terrestrial Magnetism.=
MAGNETIC OBSERVATIONS IN EGYPT, 1895-1905, WITH A SUMMARY OF PREVIOUS
MAGNETIC WORK IN NORTHERN AFRICA, by B. F. E. KEELING. (Survey
Department Paper, No. 6). 1907. 65 pp., 4 maps. Price, 100 milliemes.
MAGNETIC OBSERVATIONS MADE FROM APRIL TO DECEMBER, 1907, AT HELWÂN
OBSERVATORY. 8 pp. Price, 25 milliemes.
MAGNETIC OBSERVATIONS MADE DURING 1908 AT HELWÂN OBSERVATORY. 11 pp.
Price, 25 milliemes.
The same for 1909, 1910, and 1911. Price, 50 milliemes each.
MAGNETIC SURVEY OF EGYPT, VALUES OF THE MAGNETIC ELEMENTS AT 81
STATIONS. 6 pp. and 1 illustration. Price, 50 milliemes.
STANDARDIZATION OF THE MAGNETIC INSTRUMENTS AT HELWÂN OBSERVATORY
DURING 1907, by H. E. HURST. (Survey Department Paper, No. 8). 1908. 45
pp., 4 illustrations. Price, 100 milliemes.
=Miscellaneous.=
ANNUAL REPORTS ON THE WORK OF THE SURVEY DEPARTMENT, by the
Director-General, as follows: 1905, 120 milliemes; 1906, 1907, 1908,
1909, and 1910, 100 milliemes each.
CHEMISTRY OF THE RIVER NILE, by A. LUCAS. 1908. (Survey Department
Paper, No. 7). 78 pp., 1 map, 1 illustration. Price, 150 milliemes.
COLLECTION OF STATISTICS OF THE AREAS PLANTED IN COTTON in 1909, by
E. M. DOWSON and J. I. CRAIG. 1909. English or Arabic. 77 pp., 8
illustrations. Price, 150 milliemes each.
COLLECTION OF STATISTICS OF THE AREAS PLANTED IN COTTON IN 1910. 1910.
English or Arabic. Price, 50 milliemes each.
KHEDIVIAL OBSERVATORY, HELWÂN, BULLETINS. Nos. 1, 2, 3, 4, and 5.
Price, 20 milliemes each.
PRESERVATIVE MATERIALS USED BY THE ANCIENT EGYPTIANS IN EMBALMING, by
A. LUCAS, F.I.C. (Survey Department Paper, No. 12). 1911. 59 pp. Price,
100 milliemes.
WORK OF THE LABORARIES.—A REPORT ON THE, by A. LUCAS, F.I.C., for 1910
and 1911. Price, 50 milliemes each.
* * * * *
[Footnote: £ 1 = 975 milliemes; $ 1 = 200 milliemes; Mk. 1 = 48
milliemes; Fr. 1 = 38 milliemes.]
* * * * *
I. N. 647-1912-400 ex.
* * * * *
Transcriber's note:
Changes in the Corrigenda have been made.
The Corrigenda has been moved from: before the frontispiece to:
after the Index.
pg xi Changed: Hadal Aweih Meisah to: Aweib
pg 30 Changed: very greath depth to: great
pg 33 (Footnote 58) Changed: Upsala, 1188-1885 to: 1881-1885
pg 49 (Footnote 72) Changed: the altitude of the ines to: lines
pg 60 in the row of Field point 472 Changed: Wdi Abu Hireiq to: Wadi
pg 67 second table, first row, second column Changed: 36″ 38′ 56″
to: 36° 38′ 56″
pg 91 Changed: the ruins of Darabib to: Darahib
pg 107 Changed: about latitude 24° 15 to: 24° 15′
pg 121 Changed: Gebel Balamhandeit to: Belamhandeit
pg 142 Changed: to joins Wadi Hasium to: join
pg 194 Changed: longitude 34″ 40′ 34″ to: 34° 40′ 34″
pg 204 Changed: latitude 23″ 25′ 19″ to: 23° 25′ 19″
pg 205 Changed: longitude 34″ 59° 19′ to: 34° 59′ 19″
pg 206 Changed: object in the lanscape to: landscape
pg 228 Changed: foot of the mountian to: mountain
pg 254 Changed: formed of while granitic sand to: white
pg 292 (caption of Fig. 23) Added: g, before: ground mass
pg 300 (caption of Fig. 30) Changed: _nb_, hornblende to: _hb_
pg 300 (caption of PLATE XXIV.) Changed: =FINE-QRAINED GABBRO= to:
=FINE-GRAINED=
pg 311 (caption of Fig. 41) Changed: + 40 to: × 40
pg 312 (caption of Fig. 42) Changed: + 40 to: × 40
pg 326 Changed: are belived to represent to: believed
pg 327 (caption of Fig. 49) Changed: [12,123] to: [12,128]
pg 353 (Footnote 137) Changed: sometimes missspelt to: misspelt
pg 380 Changed: [Bir] „ Qababit to: Qabatit
pg 391 removed a duplicate entry of:
"[Wadi] „ [Kreiga] „ diabase dykes of, 309."
pg IV Changed: to the Pacific por-s to: ports
Minor changes in punctuation have been done silently.
Other spelling inconsistencies have been left unchanged.
Periods at the end of words have been removed in the table
"CLASSIFICATION OF IGNEOUS ROCKS" for the sake of table width.
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