es of floating ice would cause quick condensations of vapor, so that
fogs and clouds would deprive the vertical rays of the sun of half their
power. The whole planet, therefore, would receive annually a smaller
portion of the solar influence, and the external crust would part, by
radiation, with some of the heat which had been accumulated in it,
during a different state of the surface. This heat would be dissipated
in the spaces surrounding our atmosphere, which, according to the
calculations of M. Fourier, have a temperature much inferior to that of
freezing water.

After the geographical revolution above assumed, the climate of
equinoctial lands might be brought at last to resemble that of the
present temperate zone, or perhaps be far more wintry. They who should
then inhabit such small isles and coral reefs as are now seen in the
Indian Ocean and South Pacific, would wonder that zoophytes of large
dimensions had once been so prolific in their seas; or if, perchance,
they found the wood and fruit of the cocoa-nut tree or the palm
silicified by the waters of some ancient mineral spring, or incrusted
with calcareous matter, they would muse on the revolutions which had
annihilated such genera, and replaced them by the oak, the chestnut, and
the pine. With equal admiration would they compare the skeletons of
their small lizards with the bones of fossil alligators and crocodiles
more than twenty feet in length, which, at a former epoch, had
multiplied between the tropics: and when they saw a pine included in an
iceberg, drifted from latitudes which we now call temperate, they would
be astonished at the proof thus afforded, that forests had once grown
where nothing could be seen in their own times but a wilderness of snow.

If the reader hesitate to suppose so extensive an alteration of
temperature as the probable consequence of geographical changes,
confined to one hemisphere, he should remember how great are the local
anomalies in climate now resulting from the peculiar distribution of
land and sea in certain regions. Thus, in the island of South Georgia,
before mentioned (p. 98), Captain Cook found the everlasting snows
descending to the level of the sea, between lat. 54 degrees and 55
degrees S.; no trees or shrubs were to be seen, and in summer a few
rocks only, after a partial melting of the ice and snow, were scantily
covered with moss and tufts of grass. If such a climate can now exist at
the level of the sea in a