and water have thus been the chief tellurian anarchists, and the shaking
of continents and the constant shifting of level in sea and land still
continue to attest their restless energies. That igneous matter has,
during many periods, been protruded from below--that mountains have
risen in succession from the sea, and injected their molten substance
through cracks and fissures of superincumbent strata--are facts resting
on indubitable evidence. Many masses of granite became the solid bottom
of some portions of the sea before the secondary strata were laid
gradually upon them. The granite of Mont Blanc rose during a recent
tertiary period. "We can prove," says Professor SEDGWICK, "more than
mere shiftings of level, and that many portions of sea and land have
entirely changed their places. The rocks at the top of Snowdon are full
of petrified sea-shells; the same may be said of some high crests of the
Alps, Pyrenees, and Andes. We have proof demonstrative that many parts
of Scotland, and that all England, formed, during many ages, the solid
bottom of the sea. It may be true that the antagonist powers of nature
during the human period have reached a kind of balance. But during all
geological periods there have been such long intervals of repose, or of
such gradual movements, that we may trace the history of the earth in
the successive deposits formed in the waters of the sea." This is the
great business of geology.

Although at first sight the interior of the earth appears a confused
scene, after careful observation we readily detect in it a regularity
and order from which much instructive light is thrown on its past
vicissitudes. The deposition of the aqueous rocks and the projection of
the volcanic have unquestionably taken place since the settlement of the
earth in its present form. They are, indeed, of an order of events which
are going on under the agency of intelligible causes, down to the
present day. We may therefore consider these generally as recent