(to resort to common language) is cooled a good way down. But when
new sediment settles at the bottom of that sea, the heat rises up to
what was formerly the surface; and when a second quantity of sediment
is laid down, it continues to rise through the first of the deposits,
which then becomes subjected to those changes which heat is
calculated to produce. This process is precisely the same as that of
putting additional coats upon our own bodies; when, of course, the
internal heat rises through each coat in succession, and the third
(supposing there is a fourth above it) becomes as warm as perhaps the
first originally was.

In speaking of sedimentary rocks, we may be said to be anticipating.
It is necessary, first, to shew how such rocks were formed, or how
stratification commenced.

Geology tells us as plainly as possible, that the original
crystalline mass was not a perfectly smooth ball, with air and water
playing round it. There were vast irregularities in the surface,--
irregularities trifling, perhaps, compared with the whole bulk of the
globe, but assuredly vast in comparison with any which now exist upon
it. These irregularities might be occasioned by inequalities in the
cooling of the substance, or by accidental and local sluggishness of
the materials, or by local effects of the concentrated internal heat.
From whatever cause they arose, there they were--enormous granitic
mountains, interspersed with seas which sunk to a depth equally
profound, and by which, perhaps, the mountains were wholly or
partially covered. Now, it is a fact of which the very first
principles of geology assure us, that the solids of the globe cannot
for a moment be exposed to water, or to the atmosphere, without
becoming liable to change. They instantly begin to wear down. This