sand and mud would be deposited on its bare and uneven surface: after the
formation near the shore of a new rocky shoal, fresh subsidence would carry
it down and allow it to be smoothly covered up. But in the case of the many
cliff-bounded islands, for instance in some of the Canary Islands and of
Madeira, round which the inclination of the strata shows that the land once
extended far into the depths of the sea, where there is no apparent means
of hard rock being worn away--are we to suppose that all these islands have
slowly subsided? Madeira, I may remark, has, according to Mr. Smith of
Jordan Hill, subsided. Are we to extend this conclusion to the high, cliff-
bound, horizontally stratified shores of Patagonia, off which, though the
water is not deep even at the distance of several miles, yet the smooth
bottom of pebbles gradually decreasing in size with the increasing depth,
and derived from a foreign source, seem to declare that the sea is now a
depositing and not a corroding agent? I am much inclined to suspect, that
we shall hereafter find in all such cases, that the land with the adjoining
bed of the sea has in truth subsided: the time will, I believe, come, when
geologists will consider it as improbable, that the land should have
retained the same level during a whole geological period, as that the
atmosphere should have remained absolutely calm during an entire season.


CHAPTER II. ON THE ELEVATION OF THE WESTERN COAST OF SOUTH AMERICA.

Chonos Archipelago.
Chiloe, recent and gradual elevation of, traditions of the inhabitants on
this subject.
Concepcion, earthquake and elevation of.
VALPARAISO, great elevation of, upraised shells, earth of marine origin,
gradual rise of the land within the historical period.
COQUIMBO, elevation of, in recent times; terraces of marine origin, their