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.