OF THE DISTRICT. 
167 
by its upper beds, about Hawes, Bainbridge, and Askrigg At the 
latter place is Bow force, one of the prettiest low falls in the dale. The 
waterfalls in Aysgarth are over this rock, and when water is abun- 
dant their effect is very fine. 
In Bolland the surface of this limestone nowhere probably exceeds 
1000 feet above the sea, it is not so bold in feature as the districts 
further to the north, but both here and about Clithero its aspect is 
similar. 
One remarkable character of this limestone throughout its whole 
course in the North of England, and indeed through all parts of the 
kingdom where its mass is considerable and not much divided by 
interposed shales and grits, is the occurrence of subterranean caverns. 
These are far too numerous to be individually described, for they occur 
in nearly all parts where the limestone is elevated so as to permit 
water to pass downwards through the rock, or to justify a suspicion 
that in some former condition of the surface it may have passed ; 
yet it must be remarked, that they are most frequent in those parts 
of Yorkshire where the limestone is thickest, and collected into one 
mass, and that they are frequently situated in the side of a valley. This 
is the case by Barbon beck near Dent, in Leek beck on the west 
front of Graygarth, Yordas cove in Ivingsdale, Weathercote cove in 
Ingletondale, a cave in Claphamdale, Hurtlepots in Ribblesdale, a cave 
above Kettlewell, and Gowden Pot hole in Nidderdale. On the con- 
trary in Greenhow hill, on the north front of Ingleborough, and in 
Bolland, this is not the case. From whatever cause the cave originated, 
in most instances each has been traversed by streams, or bathed by 
the dripping of water containing carbonic acid. Thus the cave has 
been in some instances enlarged and modified, and is still undergoing 
change, in others the original surfaces are partially or wholly encrusted 
with crystallized carbonate of lime left by percolating water, and some- 
times hanging in long stalactites from the roof, or rising in wrinkled 
columns of stalagmite from the floor. The cavern in Greenhow hill, 
though little known and seldom visited, is one of the most remarkable 
