1835--Isle of Santa Maria raised ten feet--Chili, 1822--Extent of
country elevated--Aleppo and Ionian Isles--Earthquake of Cutch in
1819--Subsidence in the Delta of the Indus--Island of Sumbawa in
1815--Earthquake of Caraccas in 1812--Shocks at New Madrid in 1811
in the valley of the Mississippi--Aleutian Islands in
1806--Reflections on the earthquakes of the nineteenth
century--Earthquake in Quito, Quebec, &c.--Java, 1786--Sinking down
of large tracts.

In the sketch before given of the geographical boundaries of volcanic
regions, I stated, that although the points of eruption are but thinly
scattered, constituting mere spots on the surface of those vast
districts, yet the subterranean movements extend simultaneously over
immense areas. We may now proceed to consider the changes which these
movements produce on the surface, and in the internal structure of the
earth's crust.

_Deficiency of ancient accounts._--It is only within the last century
and a half, since Hooke first promulgated, in 1688, his views respecting
the connection between geological phenomena and earthquakes, that the
permanent changes affected by these convulsions have excited attention.
Before that time, the narrative of the historian was almost exclusively
confined to the number of human beings who perished, the number of
cities laid in ruins, the value of property destroyed, or certain
atmospheric appearances which dazzled or terrified the observers. The
creation of a new lake, the engulfing of a new city, or the raising of a
new island, are sometimes, it is true, adverted to, as being too
obvious, or of too much geographical or political interest to be passed
over in silence. But no researches were made expressly with a view of
ascertaining the amount of depression or elevation of the ground, or any
particular alterations in the relative position of sea and land; and
very little distinction was made between the raising of soil by volcanic
ejections, and the upheaving of it by forces acting from below. The same
remark applies to a very large proportion of modern accounts: and how
much reason we have to regret this deficiency of information appears
from this, that in every instance where a spirit of scientific inquiry
has animated the eye-witnesses of these events, facts calculated to
throw light on former modifications of the earth's structure are
recorded.

_Phenomena attending earthquakes._--As I shall confin