212 JOWETT AND MUFF : GLACIATION OF BRADFORD, ETC. 
rather sandy, greyish boulder-clay is found to spread up the 
northern slopes of Combe Hill to over 1,350 feet. The mounds 
near Cowloughton have been mentioned already (p. 205). On 
the summit of Combe Hill the surface is covered by angular 
debris of the underlying grits, and a search failed to reveal any 
drift-pebbles. No boulder-clay was found on the southern and 
south-eastern slopes of the hill, though had the hill been over- 
ridden by the ice, one would expect some boulder-clay to be 
preserved there. 
On the western side of the col, between Combe and Crow 
Hills, a thick deposit of stony boulder-clay reaches up to within 
50 feet of the watershed (1,120 feet). Southwards, on the 
western flanks of Bouls worth, the drift ranges again almost up 
to 1,400 feet. On the eastern side of Combe Hill the upper 
limit of the drift sinks into the Worth Valley and then rises 
again on the moors to the south, but does not regain its former 
height, a gradual diminution taking place all down Airedale. 
Thus the evidence seems to show that whilst the ice on the 
Lancashire side of the Pennine axis reached a level of about 
1,400 feet above O.D., it probably did not cross the watershed 
in the gap between Combe and Crow Hills. The evidence 
derived from the overflow-channels as to the maximum extension 
of the ice, to be brought forward in the sequel, is in agreement 
with this conclusion. 
A huge boulder of grit, measuring 29 x 25 x 21 feet, and 
known as the Hitchingstone, lies near the top of an eminence 
on the moor, nearly two miles south-west of Sutton, at an elevation 
of 1,175 feet above O.D. There has been a good deal of dis- 
cussion as to whether the Hitchingstone is a transported block, 
or whether it has weathered out from rock in situ* It is obviously 
not in situ, and in its present position it could not have fallen 
from any cliff or crag. There are two thick beds of grit in the 
immediate neighbourhood from which it may have been derived. 
One of these forms Earl Crag, situated a mile to the north ; the 
other the hill on which the block lies. Boulder-clay, sometimes 
*See Brit. Assoc. Report for 1874, p. 195. Brit. Assoc. Report for 
1879, p. 140. Dakyns. Geol. Mag., Dec. II., vol. iv., 1879, p. 96. 
Adamson. Naturalist, 1886, p. 333. 
