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.