110 
—the difficulty has disappeared, and the efficiency of those 
subaerial agents of which we have been speaking is now confidently 
asserted. Let us go into figures for a moment. Suppose we 
assume that material of the depth of one-tenth of an inch is 
removed from each side of a valley every year, at the end of ten 
thousand years that valley would be one hundred and sixty-six feet 
wider than it is now, and in a hundred thousand years it would be 
1660 feet wider. Now one tenth of an inch is not a great quantity 
to be removed in a year, and one hundred thousand years is not a 
great length of time when you have millions to take at; yet even 
with those figures we see that a valley would be produced greater 
by far than the majority of our present valleys, so that I think 
there can be little doubt about the competency of the agents of 
which we have been speaking to do the work ascribed to them. 
In the country about Ennerdale there exists a similar connec- 
tion between geological structure and scenery to that which has 
been seen to prevail at Keswick and along our sea-coast. The 
tame and even outline of the range of Dent and Kinniside Cop 
contrasts strongly with the torn and rugged features of the Pillar 
and its neighbours ; and so upon examination we find that there is 
great difference in their geological structure, Dent and Kinniside 
being formed of Skiddaw Slate, while the pillar is composed of 
volcanic lavas andashes. The Pillar Stone standing conspicuously 
out from the flanks of the Pillar mountain is another apt illustra- 
tion of our subject. Close inspection shews that that very remark- | 
able feature of the Ennerdale valley consists of a rock which is 
much harder than that immediately surrounding it. Whence its 
curious and remarkable prominence. 
In travelling by rail from Whitehaven to Furness, we obtain 
a splendid view of the western hills of the Lake Country. We see 
their varied outline, and how in every case it alters where there is 
alteration in their rocky structure; the distant changing profile 
being in fact a sure index of the petrological changes that are met 
with on a nearer acquaintance. And so, wherever we go, there is 
the same association of external form and internal substance, the 
one changing as the other changes, being together knit by the 
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