=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′.