22 MALLET : ADEN AND VICINITY. 



6 inches deep and 15 or 20 feet broadj with a rapid flow of water. As 

 far as^ and even beyond Lahej, the river is never dry throughout the 

 year^ but it is only after the heaviest floods that a drop reaches the sea. 

 The water which leaves the hiUs therefore is all disposed of in passing' 

 over the plain^ by evaporation^ — which as the water is so largely spread 

 over the fields for irrigation purposes^ no doubt accounts for a consider- 

 able fraction of it^ — by absorption by vegetation^ and lastly and I believe 

 chiefly, by soaking into the ground. Flowing as the river does over 

 sand and sandy soil, for some 20 miles as the orow flies, from its 

 debouchure out of the hills to where it becomes dried up, the loss by 

 absorption into the ground cannot but be enormous, and we accordingly 

 find the gravel bed south of Lahej saturated with water at about 

 50 feet below the surface. No doubt there is a slow undei'ground 

 current towards the sea, particularly beneath the bed of the river. At 

 Huswah, close to the shore of Aden Harbour, I was informed that while 

 one well dug some distance from the river course yields brackish water, 

 another in the bed of the stream afibrds water which is pure and good^ 

 no doubt owing to an underground fiow. 



Around Lahej a large quantity of water is obtained for irrigation 

 by means of common wells, and the yield is plentiful although the 

 depth to which they are sunk below the water line is very small. The 

 deepest I measured contained eight feet of water, and another at Mahilla, 

 only two, the water in this however having been lowered by drawing. 

 The water in this, as in all the wells of the neighbourhood which I 

 examined, was perfectly sweet and good. It was being drawn out for 

 irrio-ation as fast as the cattle could raise it. The bullocks woi-k four 

 hours a day, two in the morning and two in the evening, but the villagers 

 said that if the water were required, they might work constantly 

 without draining the well, and such I have no doubt is the case, for as 

 the water-bearing stratum consists of rounded pebbles imbedded in 

 loose sand, the water is free to percolate through it with the greatest 



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