324 
CUTTRISS : NOTES OX THE CAVES OF YORKSHIRE. 
It is hardly probable that the tilting of the strata, resulting from 
the elevation caused by the great Craven dislocation, would have 
been solely, if at all, responsible for this change in the aspect of the 
caves. 
A distinctive feature of this section is the entire absence of 
pot-holes. For a long time this difference between two adjacent 
districts in the same formation was very perplexing, as pot-holes are 
characteristic of the other section. The solution of the problem 
was, however, eventually found to be quite simple. A pot-hole differs 
from a cave, in the ordinary acceptation of the word, in that it is a 
more or less vertical pit, down which a stream of water plunges, 
often to an enormous depth. (The deepest at present known in this 
country is Rowten Pot, in Kingsdale, which has a depth of 365 ft.) 
Bearing in mind the fact that here the limestone is entirely un- 
covered, except for the surface soil, and does not receive drainage 
from higher ground, the one agent necessary to the formation of 
pot-holes is absent, viz., a more or less perennial stream. The rain 
falling on the ground at once sinks below, without collecting in 
surface streams. For this reason pot-holes need never be looked for 
where limestone forms the highest ground. 
Sink-holes or swallow-holes are observed in all limestone 
districts, being merely conical depressions in the ground caused 
by the dissolving away of the rock, at those places specially favour- 
able for absorbing the surface water. Many of these sinks, some of 
considerable size, are on the open ground above the Attermire 
Scars, indicating distinct lines of subterranean drainage towards the 
north-east. 
