8 On Abyssinian Tube Wells. 



When rock or other hard substance is come to, that is 

 when the pipe ceases to go down easily under the blows of 

 the monkey, it should be driven no more, as the pipe would 

 bend where it is weakened by the holes, if it got- many blows 

 after touching the rock. 



When the pipe gets down to a depth where water may 

 be expected, it is well to let a plummet down into it to 

 ascertain if there is water. If so, and it has risen high, it 

 may be well to screw on the pump and try if it is merely 

 soakage water, or whether it has come on a spring. With 

 the first pump I put down I found at twenty feet that there 

 was eight or nine feet of water, and I tried the pump on it. 

 I afterwards drove it to a depth of twenty-six feet, and the 

 water rose twenty feet in the tube ; notwithstanding, how- 

 ever, their being so much water in the tube, it came up at 

 first only slowly, and there was great pressure on the handle 

 of the pump. It required several hours pumping before the 

 water became clear and came with a free now. But the 

 success of the pump may be judged from the fact that I fitted 

 first two troughs containing each 594 gallons connected 

 together by a tube, and the two were filled in an hour and 

 a quarter, the pump throwing out the water as fully at the 

 end as in the beginning ; showing that the springs were fully 

 equal to the pipe, of which the bore is two inches. 



The doubt I had about tube wells being equal to pumps 

 which have a large reservoir of say six feet square, was that 

 there was no reserve of water, and that they would exhaust 

 under half an hour's pumping ; but I now see that if you get 

 a good spring it is quite equal to the pump with storage. 

 Moreover, where there is a good spring, you can by the tube 

 well get down to the bottom of it ; whereas in well sinking, 

 the men are obliged to cease working before they get down 

 as far as would be desirable, by reason of the flow of water. 



At first a great deal of mud comes up, then sand. The 

 water gradually clears till it is as free from sediment as any 

 of the other pumps. 



The second pump I put down was in a more doubtful spot 

 than the first. It had to be pumped a good while before 

 water came. For a good while again it only gave about a 

 gallon of thick water a minute. The pressure on the pump 

 was so great that it was quite plain it was drawing the water 

 through the ground, that it was in fact tearing springs open 

 by main force. As the pumping went on, the water would 

 ^lear for a while, and then apparently a fresh spring would 



