Discussions on climate and cosmology / by James Croll.

  • James Croll
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: Discussions on climate and cosmology / by James Croll. Source: Wellcome Collection.

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    thereby reducing the temperature. Since, then, the earth loses as well as gains the greater part of her heat in equatorial regions, it is there that the sub- stance best adapted for preventing the dissipation of that heat must be distributed in order to raise the general temperature. Now, of all substances in nature, water seems to possess this quality in the highest degree; and, being a fluid, it is adapted by means of currents to carry the heat which it receives to every region of the globe. It has been urged as an objection to any ocean- current theory that, while it provides the requisite amount of heat, it fails to remove the three or four months' darkness of an Arctic winter, which must have proved fatal to plants of the Miocene period. This objection seems, however, to have no foundation in fact. Sir Joseph Hooker stated to the Eoyal Society, at the close of the reading of Prof. George Darwin's paper, that palms and other plants brought from the tropics survived the winter in St. Peters- burg without damage, though matted down in absolute darkness for more than six months; and he was of opinion that the want of sunlight during the Arctic winter would not be very prejudicial to the plants. But a cause must be found as well for the cold of the Glacial Epoch as for the warm climate of the Arctic regions that obtained in Miocene times. Ac- cording to Lyell the continents would require to be moved to high temperate and polar regions to bring about a glacial condition of things in Britain. But this is an assumption which the present state of geological science will hardly admit. It is perfectly certain that there have been no such vast revolutions in physical geography in post-Tertiary times. Tendency in Geology to Cataclysmic Theories.—
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