with an unusual amount of moisture. This speculation seems to me,
however, both improbable and superfluous; improbable, because no
traces of any such cataclysm have been discovered, and it is more
than doubtful whether the generation of steam in the tropics, however
large the quantity, would produce glaciation of the polar regions.
The ascent of steam and heated air loaded with vapor to the altitude
of refrigeration would, as it seems to me, result in the rapid
radiation of the heat into space, and the local precipitation of
unusual quantities of rain; and the effect of such a catastrophe
would be slowly propagated and feebly felt in the Arctic and
Antarctic regions.

When we consider the magnitude of the ice-sheets which, it is claimed
by the glacialists, covered the continents during the Drift age, it
becomes evident that a vast proportion of the waters of the ocean
must have been evaporated and carried into the air, and thence cast
down as snow and rain. Mr. Thomas Belt, in a recent number of the
"Quarterly Journal of Science," argues that the formation of
ice-sheets at the poles _must have lowered the level of the oceans of
the world two thousand-feet!_

The mathematician can figure it out for himself: Take the area of the
continents down to, say, latitude 40°, on both sides of the equator;
suppose this area to be covered by an ice-sheet averaging, say, two
miles in thickness; reduce this mass of ice to cubic feet of water,
and estimate what proportion of the ocean would be required to be
vaporized to create it. Calculated upon any basis, and it follows
that the level of the ocean must have been greatly lowered.

What a vast, inconceivable accession of _heat_ to our