302 
HUGHES : INGLEBOROUGH. 
hope for is the selection of the " geological eqaivalent " * or 
what was afterwards called the " homotaxeoas deposit," f which 
is most convenient for each locality. 
It is about 70 feet from the base of the grit on the soath 
side to the top of the hill, and, allowing something for the general 
rise of the beds to the north-west, we ma}^ estimate the thickness 
of the pebbly grit at about So feet and the flaggy grit at about 
30 feet more. 
In one place on the west side the coa,rse grit rests on a fine 
sandstone, which, as may be inferred from the fragments seen 
below, passes down into sandy shale. 
Tt is obvious that enormous masses of the cliff round the 
top of the hill have crumbled down or sUpped bodily on to the 
ledge formed by the Main Limestone. The grit is traversed 
by great open joints, the water in which freezes and shatters 
the rock, while the shale at the top of the Main Limestone 
facilitates slips. The fractured rocks so often seen in such 
situations after thunderstorms suggest that lightning may 
have materially helped the work of destruction at these high 
elevations. Considerable slips are seen along the east side, 
especially at the south-east corner, where a small fault has 
probably helped to determine their mode of occurrence. The 
fallen blocks are often from six to ten feet in length, but it is 
diflficult to explain the position of the heaps of broken rock 
that occur near the top. Some may have been pushed forward 
by ice, and represent a stage in its recession, as, for instance, 
the boulders known as the " White Stones." AJl along the 
east and south-east outcrop of the Main Limestone the beds 
are turned over as if under the influence of a forward thrust, 
and many large masses lie far beyond where we should naturally 
expect to find them. On the north side especially the talus 
presents a grand scene of desolation, like the ruin of some 
Cyclopean wall. In some cases the main mass of this rampart 
of fallen rock stands off from the base of the cliff, forming a sort 
of lunette in advance of it. This may be due to the blocks 
* Whewell, History of the Inductive Sciences, 1837, Vol. III., p. 532. 
t Huxley, Q.J.G.S., Vol. XVIIL, 1802, p. xlii., Vol. XXVI., 1870, 
p. xlii. 
