would be recalled, as it were, into existence by the removal of the
rocks under which they are now buried.

There seems nothing in the deep sections of the Val del Bove to indicate
that the lava-currents of remote periods were greater in volume than
those of modern times; and there are abundant proofs that the countless
beds of solid rock and scoriae were accumulated, as now, in succession.
On the grounds, therefore, already explained, we must infer that a mass
so many thousand feet in thickness must have required an immense series
of ages anterior to our historical periods for its growth; yet the whole
must be regarded as the product of a modern portion of the tertiary
epoch. Such, at least, is the conclusion that seems to follow from
geological data, which show that the oldest parts of the mountain, if
not of posterior date to the marine strata around its base, were at
least of coeval origin.

Some geologists contend, that the sudden elevation of large continents
from beneath the waters of the sea have again and again produced waves
which have swept over vast regions of the earth.[582] But it is clear
that no devastating wave has passed over the forest zone of Etna since
any of the lateral cones before mentioned were thrown up; for none of
these heaps of loose sand and scoriae could have resisted for a moment
the denuding action of a violent flood. To some, perhaps, it may appear
that hills of such incoherent materials cannot be of very great
antiquity, because the mere action of the atmosphere must, in the course
of several thousand years, have obliterated their original forms. But
there is no weight in this objection; for the older hills are covered
with trees and herbage, which protect them from waste; and, in regard to
the newer ones, such is the porosity of their component materials, that
the rain which falls upon them is instantly absorbed; and for the same
reason that the rivers on Etna have a subterranean course, there are
none descending the sides of the minor cones.

No sensible alteration has been observed in the form of these cones
since the earliest periods of which there are memorials; and there seems
no reason for anticipating that in the course of the next ten thousand
or twenty thousand years they will undergo any great alteration in their
appearance, unless they should be shattered by earthquakes or covered by
volcanic ejections.

In other parts of Europe, as in Auvergne and Velay, in France, si