We have already described the intermittent character of the flow in the case of some of the larger wells in the southern part of the oasis. The circumstance is apparently due to the temporary blocking of the bore-hole by sediment, and the consequent increase of water and gas pressure below, which at intervals forces the sediment from the channels and restores the normal flow. Something of the same nature was also noticed in Bore No. 42, in the course of experiments carried out to determine the height to which the water would rise in an open pipe fixed to the end of the casing. At intervals a distinct gurgling and bubbling took place in the pipe, the water at the same time rising to as much as 8 centimetres above its normal level, with distinct oscillations of a pressure-gauge attached to the well. The ebb and flow did not, however, take place at regular intervals, but at periods varying from four to nine minutes. I think a sufficient explanation of these phenomena is the probable variation in the amount of gas finding its way into the bore; and certainly, after several years’ observation of the flows of a large number of bores, I cannot admit that there is the slightest evidence in favour of the view that the flows of the wells have a periodicity dependent on the rise and fall of the Nile. One frequently hears it stated that the oases were far more thickly populated and better watered in olden times than at the present day. This belief is based on the existence in many parts of the depression of extensive remains of temples, forts, and villages, on the widespread traces of formerly cultivated lands, and on the abundance of sanded-up wells. It must not, however, be forgotten that the remains in question belong to successive generations, and that there is as yet no evidence to enable us to determine how much of the land, or how many of the wells, were in use at one and the same time. The evidence is, however, sufficiently pronounced to justify the conclusion that under the Romans the oasis of Kharga was far more flourishing than in modern times, a large part of the population being engaged, not in agriculture, but in mining, boring, and in the excavation of subterranean aqueducts. [Illustration: LANDS UNDER RECLAMATION AT BORE NO. 39.]