Ragnarok : the age of fire and gravel

GREAT HEAT A PREREQUISITE. 61

rists to suppose that the Ice period was attended, if not in part caused, by a far more abundant evaporation from the surface of the Atlantic than takes place at present ; and it has even been conjectured that submarine volcanoes in the tropics might have loaded the atmosphere 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 discoyered, 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