Twelve kilometres to the south of Kharga lies the village of Gennâh. The intermediate country is largely covered by sand, which in the neighbourhood of the village has accumulated into large dunes, threatening it and its magnificent wells, Ain Estakherab and Ain Magarin, with ultimate destruction. Ain Estakherab is undoubtedly the finest well in the Libyan Desert, and has been running for hundreds, if not for thousands, of years; but unless special measures are taken to cope with the advance of the dunes immediately to the north and north-west, this splendid flow of water is doomed to destruction within the next ten or twenty years. Owing to the encroachment of the sand there is very little land available for cultivation near the village, the bulk of the water from the two wells being conducted in an open channel to the low-lying plain south-east of the hill-range known as the Gorn el Gennâh. This channel traverses 7 or 8 kilometres of porous desert before it reaches the first of the cultivated fields in the neighbourhood of the Gorn, and there is in consequence very great loss of water through seepage and evaporation. The famous wells of Gennâh differ from most of those in the northern part of the oasis in that their mouths are large and deep pools of limpid water, from the depths of which great bubbles of gas constantly ascend to the surface. Little or nothing is known as to the age and depth of either of these wells; they have never been cleaned out in modern times, and are closed in at a depth of a few metres from the surface in such a way as to prevent soundings being made. With the object of determining if the large discharges are due to the wells being situated on exceptionally low ground, I recently had a line of levels run from headquarters to Gennâh. Contrary to expectation, it was found that Ain Estakherab and Ain Magarin discharged at levels considerably above the average elevation of the wells of the Kharga district; possibly, therefore, the exceptional flows in this district are due to its comparative isolation, and to the immunity thus obtained from the interference of other wells. Between the villages of Kharga and Gennâh, along a north and south belt lying somewhat to the east and on the downthrow side of the fault, are a number of wells whose waters are almost invariably more or less charged with ochre and alkaline salts. In some cases the proportion of dissolved salts is sufficiently great to render the water unfit for either drinking or irrigation, and even where it can be used for the latter purpose, ochre is deposited to such an extent as to bind the soil into a hard cake. The occurrence appears to be due to the geological position of the wells in this tract, where, owing to the beds being let down by the fault, the purple shales form the floor of the depression; it is perhaps from these beds that the waters derive their abnormally high contents of ferric oxide and other salts.