56 JEugh J. L. Beadnell — Floiving Wells, KImrga Oasis. 



The sandstones of this series form the highest water-bearing horizon 

 in the oasis, and one quite distinct from the artesian-water sandstone, 

 the two being separated by a thick impervious series of dense grey 

 shales. In the district round headquarters the water is as a rule met 

 with at a depth of from five to six metres below the ground surface, 

 is not under pressure, and does not rise appreciably in boreholes, so 

 that to become available for irrigation it has to be lifted by power. 

 An ordinary borehole or small pit is, however, useless, as the inflow 

 of water through the pores of the sandstone is too slow to yield 

 a pumping supply ; in a large pit a number of small fissures are 

 usually struck, and it is through these that most of the water is 

 obtained. Provided a sufficiently large collecting tank is excavated — 

 say 5x4 metres and sunk to from one to one and a half metres 

 below the standing water-level — a supply sufficient to yield a continual 

 discharge of eight gallons a minute (or 11,500 gallons per day of 

 twenty-four hours) can usually be obtained. In especially favourable 

 localities a pit of the dimensions given above will yield 15 or even 20 

 gallons per minute, and the pumping capacity can as a rule be still 

 further increased by deepening. The extent to which this supply can 

 be drawn on without appreciably lowering the water-level has not, of 

 course, yet been determined, though in one pit alongside Bore No. 2, 

 where a ' sakia ' has been working more or less continuously for over 

 a year, the water-level has not appreciably changed. 



Unfortunately the quality of this water, at any rate in the head- 

 quarters area,^ is not uniform, in some places being quite sweet while 

 in others, only a few hundred metres distant, it is highly ferruginous 

 and more or less charged with salts. For instance, the water of a pit 

 put down at a point 570 metres E.S.E. of headquarters was found 

 on analysis to contain 63 grains of dissolved solids per gallon, the salts 

 consisting of iron, potash, and soda, with traces of lime and magnesia, 

 mostly in the form of sulphates and chlorides." The utilisation of 

 this water for purposes of irrigation would, at the rate of three 

 gallons a minute per acre, mean an annual deposition of over three 

 tons of sulphate of potash and common salt on each acre of land, 

 an amount which would of course spell ruin to its agricultural value 

 in a very short time. 



In many parts of the oasis, however, perfectly sweet water is 

 obtainable from the sandstones of this series, and that this source, as an 

 auxiliary to the artesian supplies obtained from deep borings, was 

 taken full advantage of by the ancients, is testified by tlie wonderful 

 systems of underground aqueducts which penetrate the sandstones in 

 many parts of the oasis, but more especiallj' in the districts round 

 TJm el Dabadib, Ain Lebekha, and Qasr Gyb. They were especially 

 applicable to districts where the bulk of the sandstones, as in the 

 first two localities mentioned, form extensive hills above the general 

 level of the neighbouring cultivable ground. The method was probably 



1 The headquarters of the Corporation of "Western Egypt, Ltd. ; the area over 

 ■which the boring operations referred to in this paper extend is shown on the 

 accompanying map (Fig. 1, p. 51) by a dotted line. 



- For the analyses quoted in this paper I am indebted to Mr. "William Garsed, 

 formerly of the Oasis Headquarters Staff, 



