UNDERGROUND WATERS OF NORTH-WEST YORKSHIRE. 291 
Sank at P 85, and emerged at S 108 at 1 p.m.; sank at P 86 
at" 1.30 p.m.; seen at S 109 and P 87 at 2 p.m. 
August 24th. — Seen in Weathercote Cave at 9.15 a.m.; 
seen in Hurtle Pot at 10.0 a.m. 
August 25th. — Arrived at S 112 (God's Bridge) at 12 noon. 
Between Hard Gill and Grey Wife Sike are a number of 
deep " pot-holes," the principal of which is Long Kin West 
(P 108). There is practically no water flowing down these 
pots and it was therefore impossible to test them [PI. XXVI.]. 
The sink at Grey Wife Sike (P 1) above Newby Cote was 
first tested with Methylene Blue, but as this was not detected 
in any of the surrounding streams, fluorescein was tried, with 
the result that the water was traced to the large spring known 
as Moses' Well (S 7), just above the head of Clapham Lake. 
This completes the circuit of the Ingleborough massif. 
IV. — General Conclusions. 
1. The flow of the underground waters of the area under 
consideration is radially outwards from the high ground, but 
is profoundly affected by the direction of the joints in the 
limestone, which in many cases considerably modify its course. 
2. The irregularities in the floor of Silurian and Ordovician 
rocks on which the Carboniferous Limestone rests, form under- 
ground watersheds, which in some instances influence or even 
determine the direction of flow, as, for example, in the cases of 
Norber and Moughton, and the underground watershed between 
Gaping Ghyll and Long Kin East. 
3. In many instances the subterranean streams are near 
the surface of the ground, and descend by a series of pitches, as 
in the case of Long Churn, while others plunge by way of vertical 
shafts to a depth often exceeding 200 feet from the surface. 
The joints in the limestone usually pass through one bed only, 
and are not vertically continuous through the whole mass, while, 
in some few instances, in which the deep vertical shafts occur, 
they cleave the limestone to its base. In one instance, Mere 
