16 THE UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 
The samples received at the Buck Hotel throughout the 
22nd of June remained normal. This appeared very remarkable 
and gave rise to several hypotheses which were subsequently 
discarded as the work progressed. The water at Aire Head 
increased in volume, as was anticipated from Messrs. Morrison 
and Tate's experiments in 1879,^ about two hours after the sluice 
at the Tarn had been raised, but no rise of water occurred at 
the Cove on this occasion, nor did the chemicals appear at either 
outlet. The collection of samples was therefore continued until 
August 2nd, and the necessary analyses were performed by 
Messrs. Ackroyd, Branson, Burrell, and Swan. 
Salt. 
In the search for excess of salt in the samples sent from 
Malham, June 22nd to August 2nd, the following quantitative 
estimations of chlorine were made : — 
Malham Cove ... ... ... ... ... 64 
Aire Head ... ... ... ... ... 45 
Gordale Beck 42 
Scale Gill Spring and Mill 40 
Hanlith Bridge 7 
198 
To present the bearing of these analyses at a glance, the chlorine 
estimations are plotted as a curve in the accompanying diagram 
(Plate 11. ), and in constructing the curve the average is used 
where there are many observations on one date. 
On June 22nd one ton of salt Avas put into the Smelt Mill 
Water Sink, one ton more was put in on the 23rd and also 
a third ton on the 24th ; up to July 2nd little or no alteration 
had been observed in the Cove, but on the 4th the chlorine 
figure rose to 6 '05 per 100,000, and after that it gradually fell 
to normal on the 13th and 14th. The connection between the 
'*^Proc. Yorks. Geol. and Polytec. Soc, 1879. 
