=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.