Ragnarok : the age of fire and gravel

GREAT HEAT A PREREQUISITE. 59

possible elevation of mountain-masses between the equator and the poles, that any slight changes which may have resulted from such geological causes could have had only an infinitesimal effect upon the general climate of the globe.” *

Let us reason together :—

The ice, say the glacialists, caused the Drift. What caused the ice ? Great rains and snows, they say, falling on the face of the land. Granted. What is rain in the first instance? Vapor, clouds. Whence are the clouds derived? From the waters of the earth, principally from the oceans. How is the water in the clouds transferred to the clouds from the seas? By evaporation. What is necessary to evaporation? Heat.

Here, then, is the sequence :

If there is no heat, there is no evaporation ; no evaporation, no clouds ; no clouds, no rain ; no rain, no ice ; no ice, no Drift.

But, as the Glacial age meant ice on a stupendous scale, then it must haye been preceded by heat on a stupendous scale.

Professor Tyndall asserts that the ancient glaciers indicate the action of heat as much as cold. He says:

“Cold will not produce glaciers. You may have the bitterest northeast winds here in London throughout the winter without a single flake of snow. Cold must have the fitting object to operate upon, and this object—the aqueous vapor of the air—is the direct product of heat. Let us put this glacier question in another form: the latent heat of aqueous vapor, at the temperature of its production in the tropics, is about 1,000° Fahr., for the latent heat augments as the temperature of evaporation descends, A pound of water thus vaporized at the equator has absorbed one thousand times the quantity of heat which SS a ee ie De eee ier

* “The Great Ice Age,” p. 98.