304 Mackintosh— On the Lake-district. 
from a distance, appear as if an explosive force had suddenly blown 
up a part of the earth’s crust. But this supposition would not be 
resorted to by an inductive geologist, more especially when he con- 
siders that cwms are not whole cups, but hollows with an entrance 
on one side. The innermost part of the semicircular cliff is gene- 
rally the most precipitous, as one might expect, supposing the exca- 
vating cause to have operated in an inward direction. A good 
specimen of a cwm, containing a tarn, may be seen near the top of 
Saddleback: another occurs to the north of Whiteside, and north- 
west of Grisedale Pike; and its walls, which are very lofty, present an 
imposing appearance from the road leading along Whinlatter Pass.* 
Ancient Sea-cliffs——Wherever we meet with lines of precipices 
commencing suddenly, and (to a traveller approaching them from 
behind) unexpectedly, on the side of a mountain or in situations 
where no particular disruption has occurred, we are justified in re- 
garding them as old sea-cliffs, more especially when they exhibit 
traces of having been undermined; for it is not so much by a dis- 
integrating process that the sea encroaches on rocky coasts, as by 
undermining, displacing, and scattering fragments and blocks which 
have already been so far separated by joints and rents. Even in the 
case of cliffs originally formed by a great fracture, we can generally 
see indications of the subsequent action of the sea. In travelling 
in the Lake-district we continually meet with lines of precipitous 
escarpment running along one side of a mountain-range, the other 
side of which is a gradual slope. From an inspection of Howe’s 
Model of the Lake-district at Bowness, and from subsequent obser- 
vation, I was led to notice that the steep escarpments generally face 
the east, south-east, or north-east—apparently showing that the 
indenting and undermining current must have assailed the ancient 
Cumbrian Archipelago from the east. Among the numerous 
escarpments with an easterly aspect are the following :—A part of 
the western shore of Windermere Lake; the eastern side of the Old 
Man, and Wetherlamb Mountains; the eastern declivity of the 
Crinkle Crags; the precipice called Pavey Ark: the hills running 
along the western side of Grasmere Valley, the Gap of Dunmail, 
Thirlmere, and the road to Keswick; the eastern side of Helvellyn, 
which is not only the most precipitous, but indented with voes 
separated by edges, one of the voes terminating in Red Tarn Cwm ; 
the western sides of Rydal and Scandale Valleys, near Ambleside: 
the eastern side of Kirkstone Fell, overhanging the pass; the western 
side of Kentmere Valley, &c. &c. In many of the narrow valleys, 
where the direction of the current would be deflected, we find pre- 
cipitous escarpments on both sides, or Sometimes on the exceptional 
side, as might be expected. In the western part of the Lake- 
district the steep escarpments exhibit no prevailing aspect; but this 
* Sir C. Lyell has marked an era in the history of geological discovery by his 
explanation of the denudation of the Weald of Sussex; but I am not aware that 
any geologist has yet taken notice of a cwm now in course of being excavated by the 
sea at Beachy Head. 
