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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    sun's rays, and thus allow the water of the ocean to stand at a higher temperature than it would otherwise do. Again, the slowness with which the ocean thus parts with its heat enables it to maintain that com- paratively high temperature during the long winter months. And again, it is to the mobility of the particles of water, the depth to which the heat penetrates, and the rapidity with which it is absorbed, that those great currents of warm water become pos- sible. Were the waters of the ocean like the land, not mobile, and were only a few inches at the surface reached by heat from the sun, there could be no Gulf- stream, or any great transference of heat from the southern to the northern hemisphere, or from equa- torial to temperate and polar regions, by means of oceanic circulation. Second.—' The air is probably heated more rapidly by contact with the ground than with the ocean; but on the other hand, it is heated far more rapidly by radiation from the ocean than from the land. The aqueous vapour of the air is to a great extent diather- manous to radiation from the ground, while it absorbs the rays from water, and thus becomes heated.' To this Professor Newcomb objects, as follows:—If, then, the air is really heated by contact with the ground more rapidly than by contact with the ocean, it can only be because the ground is hotter than the ocean, which is directly contrary to the theory Mr. Croll is main- taining. What I maintained was that, were it not for certain causes, the mean annual temperature of the ocean would be higher than that of the land. During the day and also during the summer the sur- face of the ground is hotter than that of the ocean; and the air, of course, will be heated more rapidly by contact with the former than with the latter. But i
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