Springs are mostly on or near the main camel roads, for the roads are naturally selected so as to utilise these constant water supplies. Frequently, however, the spring is situated up a lateral valley some little distance from the main track, and is more or less difficult of access. The springs of Abu Saafa are on a main road, where the Wadi Hodein cuts cleanly through the sandstone plateau; but those of Meneiga, being at the head of a _cul-de-sac_, are only approachable by a branch track. At large springs the Arabs generally dig out a series of basins into which the water flows, so that these are always full of water ready for the camels of a caravan to drink. At _megals_ there is usually no pool, or only a very small one, in sand or detritus; this sand is scooped out and the water is baled from the hole with a tin can. The absence of a pool is probably due to a desire to check evaporation. The flow at a _megal_ is frequently so small that only a few litres per hour can be obtained; the small trickling spring of Sikait, for instance, was yielding only twenty gallons of water _per diem_ in 1906, but even this small supply was highly prized by the miners working there, on account of its purity as a drinking water. _Megals_ are more likely to run dry than the larger springs, owing to their smaller collecting area. Any attempt to increase the flow of springs by blasting or excavation would probably only give an increase in yield at the expense of constancy; the throttling of the efflux is doubtless in many cases the chief reason for the perennial character of the yield of a spring, the rainfall being insufficient to maintain greater supplies than the springs yield at present. =Wells.= The wells of South-Eastern Egypt are mostly shallow excavations in the alluvia of the wadi floors, tapping the drainage waters which slowly percolate underground Nilewards and seawards from the mountain ranges. They are naturally more frequent in the districts near to the mountain ranges than in the lower reaches of the wadis, and the best wells are usually in well-defined trunk wadis which collect the drainage from myriads of smaller valleys. The wells sunk in the wadis at points remote from the mountain ranges are of immense importance to travellers crossing from the Nile, forming as they do the only supplies in an otherwise waterless journey of several days.