THE EARTH. 59 



Affected ; and their forms but ill adapted to the 

 conveniencies of a human habitation. In some 

 places, indeed, we find mankind still make use 

 of them as houses, particularly in those coun- 

 tries where the climate is very severe j* but in 

 general they are deserted by every race of meaner 

 animals, except the bat : these nocturnal solitary 

 creatures are usually the only inhabitants ; and 

 these only in such whose descent is sloping, or, 

 at least, not directly perpendicular. 



There is scarcely a country in the world with- 

 out its natural caverns ; and many new ones are 

 discovered every day. Of those in England, 

 Oakey-hole, the Devil's-hole, and Penpark-hole, 

 have been often described. The former, which 

 lies on the south side of Mendip-hills,t within a 

 mile of the town of Wells, is much resorted to by 

 travellers. To conceive a just idea of this, we 

 must imagine a precipice of more than a hundred 

 yards high, on the side of a mountain which 

 shelves away a mile above it. In this is an open- 

 ing not very large, into which you enter, going 

 along upon a rocky uneven pavement, sometimes 

 ascending, and sometimes descending. The roof 

 of it, as you advance, grows higher ; and, in 

 some places, is fifty feet from the floor. In some 

 places, however, it is so low that a man must 

 stoop to pass. It extends itself, in length, about 

 two hundred yards ; and from every part of the 

 roof, and the floor, there are formed sparry con- 

 cretions of various figures, that by strong itnagi- 



* PhiL Trans. voLii. p. 368 f Ibid. 



