70 DEEPDALE CAVE. 



channel to become enlarged into a succession of caves. We can, 

 however, go a step further. Starting with this small channel, it is 

 possible to account for the present shape of the second chamber. 

 If the reader will again refer to the transverse section he will 

 observe that the rock has been removed more from the right hand, 

 or south, than from the opposite side. This is not because the 

 solvent power of the water has been greater on this side than the 

 other, but because of the greater liability of blocks of stone on 

 that side falling when slightly undermined by this action, in con- 

 sequence of their overhanging character. Look at the roof of 

 this chamber ! Some day the great plate of rock which now forms 

 the roof will break off, and even if the stratum above remains in 

 its place, this will mean a per saltiim increase of some three feet 

 to the height. If this chamber should again happen to become a 

 watercourse, the broken fragments of this fallen stratum would, 

 through contact with the fluid, be, comparatively speaking, rapidly 

 dissolved away. In contrast to the above, note what a vast 

 amount of rock would have to be dissolved on the opposite side 

 before the strata immediately above could fall.* 



Whence and whither the succession of cavities, of which this 

 Deepdale cave is a link, conveyed water in the first instance, is an 

 interesting question, but, unfortunately, it is not easy to answer. 

 The first and most natural suggestion is that it drained the high 

 ground on the east, and conveyed the water into the dale. It cer- 

 tainly does so at present, only the valley being now so much lower 

 than the cave, the water has cut for itself a lower channel — the spring 

 already alluded to. But the cave has the remarkable feature that, 

 while towards the back of the first chamber, and even as near the 

 entrance as twenty-four feet, there are a succession of deposits 

 which have not yet been cut through, the threshold is of solid rock. 

 This plainly shows that the rock-floor sinks as it recedes from the 

 entrance, and the lower level of the second chamber further 



* The fall of blocks of slone is a most important factor in the enlargement 

 of caves, and in most may be seen fallen blocks which exactly fit the roof 

 immediately above. Within the entrance of the large cave at the end of the 

 Lalhkil valley are some huge tabular pieces of rock, lying just as they fell 

 from the roof. 



