573 
If we draw a line from the north side of the Sedbergh valley, 
over Killington, down by Gatebeck, to Farleton Fell, just 
where, with a free hand, we should draw the outside boundary 
of a glacier sweeping out from that valley, we find outside 
that line, blocks of granite from Shap, of pink porphyry 
from Bretherdale, and other well marked rocks, which must 
have been transported on the glacier from the north. "Within 
that line we have nothing but what might have come down 
the Sedbergh valley. Again, Baugh Fell and "Wild Boar 
Fell are carboniferous, thrown down by a great set of faults 
against the Silurian rocks of the Howgill Fells, and so, as we 
might expect, the debris which represents the eastern 
moraines of the Ravenstonedale glacier is composed of Car- 
boniferous rocks, while that on the western bank is composed 
chiefly of Silurian, while at the south end of Casterton Low 
Fell also, there is a considerable quantity of Carboniferous 
rocks in the drift. There are exceptions, of course, but they 
are not difficult of explanation when we remember that there 
is evidence of a still older drift than that of which we are 
now speaking ; and that, during the period in which these 
valleys have been again partially cleared out, there was time 
for many great modifications. Moreover, we do not yet 
know where these great ice streams started from. 
The third drift is the gravel drift of the valleys; some- 
thing allied to the kames and eskers. In general composition 
it is exactly the same as the drift last described, except that 
it has but little clay in it; also, it contains very few 
scratched stones, and on those the scratches are nearly 
obliterated, as if by subsequent washing and rolling. It lies 
in terraces sloping more or less rapidly down the valley, or in 
mounds which look like the remains of old terraces. It never 
runs far up the hill sides, and as we get to higher ground we 
find it more irregular in occurrence and more clayey in com- 
position, till often it is impossible to draw a satisfactory line 
