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On the western side of this valley the deposits of Clay and 
Sand are generally very shallow, and are entirely derived 
from the formations either immediately below or very near 
them ; but showing, by the shape of the included fragments 
of rock, that they are not only the result of aerial influences, 
but of some other force which has taken off their edges and 
worn them round. 
On the higher grounds near How Hill, the beds of Boulder 
Clay run in long mounds, parallel with the valley which I have 
mentioned, and attain a thickness of 60 or 60 feet, or perhaps 
more. Along the lower levels the mounds of Drift follow to a 
certain extent the direction of the streams, but the thickness 
of the drift is much less ; and in some places it has been 
completely washed away so as to expose the underhdng rocks. 
Such, then, are the facts, and they appear to point to a 
very interesting conclusion. For since this north and south 
valley forms a natural boundary between that Drift which is 
local and the Grlacial Drift, the conviction is forced upon one 
that here was the edge of an Ice-cap which covered all the 
hills to the west, and was cut off along this line by the 
Glacial Sea. This sea, which was covered with floating ice, 
burdened with Clay, Sand, and Boulders from the older 
Carboniferous rocks, and occasional pieces of Greenstone and 
Shap-Granite which had been carried over Stainmoor, seems 
to have moved along the edge of this Ice-cap with a strong 
current running from the north-east. The valleys in which 
the present streams run were filled with glaciers, which 
pushed their way slbwl}^ towards the sea. Beneath the Ice- 
cap, which was gently moving towards the east, there was 
formed the local Drift ; and at its edge a definite boundary of 
Boulder Clay. And the valley, so often mentioned, may have 
been produced by a strong current running along the edge of 
the Ice-cap, and bearing away the broken pieces of ice which 
from time to time fell in larger or smaller masses. These by 
