24 THE UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 
B. Engineering. 
1. Messrs. Morrison and Tate's experiments show that at that 
time (the middle of May, 1879) a large flush of water from 
the Tarn produced a responsive flow from Aire Head Springs in 
one hour and twenty-five minutes, and that the outlet from the 
Cove was affected 38 minutes later, although so much nearer 
the source of supply. 
2. The experiments in June, 1899, when flushes were sent 
down from Malham Tarn, proved that under the conditions then 
prevailing, the Aire Head Springs responded in two hours, but 
the discharge from Malham Cove was not affected by even the 
smallest measurable quantity. 
On August 7th, 1899, a large volume of water was sent 
down from Malham Tarn, at the request of Mr. Cuttriss, and 
produced a rise in the Cove stream of two inches at Malliam 
Bridge. 
On August 26th another large flush was sent down, and 
the Cove stream again rose not less than two inches at Malham 
Bridge. 
These varying results have a special significance when 
considered in conjunction with the appearance at Malham Cove 
of minute quantities of the ammonium sulphate put into the 
Malham Tarn stream in June, 1899. 
3. The Smelt Mill stream in June, 1899, only contributed 
19,800 gallons of the half million gallons flowing out at Malham 
Cove, i.e., not more than four per cent. 
The Geological Problems. 
The problems which these data set before the Geological 
Sub-Committee for solution are the following : — 
1. The determination of the route taken by each under- 
ground flow. We regard the use of the word "stream" to 
describe these movements as inaccurate, since it suggests the idea 
of a definite channel rather than a diffuse flow through many 
fissures large and small. 
