CHAPTER I.. * * * * *

* * * * * =INTRODUCTION.= * * * * *

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) 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, 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 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, 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 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. 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 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, 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. 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, 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; the “Black conical hill,” near Mersa Shab, is Gemeida; “Scragged hill” is Qash Amir; “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. 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. 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. 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). 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. 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 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, 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 travelled overland from Qena via Qoseir to Berenice, discovering several ancient stations on his way to join Purdy. Though Purdy sanguinely states 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 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 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 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. A little later, the geographical results of the expedition were embodied in an English paper read at the Royal Geographical Society. 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. 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,” 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 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 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. 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. 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.

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