radiation above the quantity of
heat received from the sun. The final cooling of its solid crust, down
to the mean temperature at which we now find it, might, as is obvious,
have been effected by a great irruption of waters, like that of which we
have distinct evidence in the diluvial deposits, and the animal remains
upon its surface. From that time, a state of equilibrium in the action
of solar and terrestrial radiation having been attained, while the mean
temperature still continues to depend upon the internal structure and
nature of the globe, the distribution of heat upon the surface, and the
vicissitudes of the seasons, have been solely influenced by the varying
relation between these two radiations, which if equal to each other in
their total amounts, differ in every different latitude, for every
successive day in the year, and during each varying hour of the day.

It has been attempted to explain this change that has unquestionably
taken place in the temperature of climate, by conceiving a change in the
situation of the earth's axis. This hypothesis, however, is shown to be
untenable by the calculations of physical astronomy: no other cause then
remains but an actual change in the condition of the earth itself.

The most remarkable of all the phenomena which the earth presents, are
the great changes of weight that have taken place in identical
formations which must have arisen from the prevalence of water, and
therefore nearly if not exactly upon the same level. The primitive or
lowest stratified rocks, probably had not water for their cause; still,
however, they must have been in the fluid state, and these are not only
found beneath all other rocks, and in the lowest places to which the
industry of man has penetrated, but they also rise and form the greatest
part in bulk of many of the highest mountains; indeed, if we except
volcanic mountains, of all the more elevated masses. The transition and
secondary formations are subject to similar although less changes of
level, rising, as has been seen, to the tops of the Pyrenees, and to
even a greater height on the sides of the Andes. The tertiary or
superior formations are found in Italy and Sicily, forming mountains
several thousand feet in height, while the latest of all, the diluvial
with its embedded mammalia, exists in the lofty table land of Quito. The
inference is irresistible, that we do not now find these deposits at the
levels where they were left by the oc