We have little, if any, information as to how the inhabitants kept up their water-supply after the withdrawal of the Romans. Probably there was a gradual diminution of the total output, as it is not at all certain that any new wells were subsequently sunk—at any rate, until after the introduction of modern hand-boring machinery some fifty or sixty years ago. On that occasion one Hassan Effendi, a servant of a French engineer of the name of Lefèvre, was sent out by the Egyptian Government to instruct the inhabitants in the use of the new machinery. Judging from their present proficiency in sinking wells through difficult strata with the most hopelessly worn and antiquated tackle, the natives did not take long to learn the new system. Unfortunately, when left to themselves without adequate supervision, they promiscuously sunk a great number of new bores, without regard to the probable effects on the older wells irrigating the existing palm-groves and cultivated lands, with the result that, more especially in the oasis of Dakhla, a great deal of harm was done. Whole districts suffered a general lowering of water-level, many of the wells ceasing to flow altogether. This was the direct outcome of the excessive number of new bores put down in certain districts where the inhabitants were sufficiently rich and influential to get and retain possession of the majority of the newly-imported boring-rigs. About ten years ago I studied the method of well-sinking used in the oases, and found it to consist of a combination of ancient and modern boring practices. Owing to the difficulty and prohibitive cost of transporting heavy steel tubes across the desert, the use of locally-made wooden casing could not be dispensed with, and as casing of this description could not possibly be made of sufficient strength to stand ‘driving,’ the upper portion of the well had of necessity to take the form of an open shaft carried down as near as possible to the water-bearing beds, the actual boring by means of the drilling-plant being confined to the later stages.