lora.

Mr. Charles Martins, who based his calculations on the temperature
during the Glacial period on the glaciers of Chamounix, concluded that
it only needed a lowering of the temperature to the extent of four
degrees Centigrade to bring the glaciers down to the plain of Geneva,
and in fact give us back the Glacial period. It need not surprise us,
therefore, that the French geologist, Mr. Falsan, the author of _La
periode glaciere_, is of opinion (p. 230) that the mean annual
temperature of France during the Glacial period was approximately from
6-9 degrees Centigrade, perhaps more. Close to the immense glaciers of
the Rhone, it might have been about six degrees. This is the actual mean
annual temperature of the South-west of Sweden and Norway, or the North
of Scotland.

Although all these investigations tend to show that the climate of
Europe during the Glacial period was by no means so severe as we are
often led to believe, yet there exists also a school of geologists who
maintain there was actually a higher temperature than at present. The
inconsistency of mentioning heat in connection with ice and snow is more
apparent, however, than real, for we must remember Tyndall's original
remark on this subject. It is the snow, he says, which feeds the
glaciers. But the snow comes from the clouds, and these again originate
from the vapours which the sun causes to be absorbed from the ocean.
Without the sun's heat, we should have no water vapour in the
atmosphere; without vapour, no clouds; without clouds, no snow; without
snow, no glaciers. The ice of glaciers, therefore, owes its origin
indirectly to the sun's heat. It has been supposed that if the sun's
heat diminished, larger glaciers would form than those existing to-day,
but the diminution of the solar heat would infallibly reduce the amount
of water vapour in the air, and would thus stop the very source of
glaciers.

Mr. Falsan even admits that without a change of the mean annual
temperature (p. 201) of Europe, the central portions of our continent
might at this period have enjoyed an insular climate. This more equable
and humid climate could, within certain limits, favour the development
of the ancient glaciers by increasing the snowfall and slackening the
summer rate of melting.

It seems evident then, according to these views, that with a
comparatively slight change of the atmospheric conditions in the British
Islands, we might have glaciers back again on all