Page:Popular Science Monthly Volume 48.djvu/35

Rh. But such a change in one portion of the earth would not be likely to take place without a coincident change everywhere else. While ice lay over a great portion of the earth, the rest of its surface may have possessed a temperate or almost semitropical climate, of peculiarly equable character the whole year round. The race of men born in such a zone would probably be hardy and strong, and this is precisely what we suppose our first ancestors to have been. But, though in what appear such favored conditions, they have left to us, in nearly all the races that have sprung from them over the whole world, a tradition of a great catastrophe—a flood. The chiefs of the then world, it seems, were saved, and, whether in one ark, or in several strangely and wonderfully built vessels, were preserved to again spread the human race. But how came this flood, and when? And why should immense quantities of rain descend, and why should the seas rise in every direction? If we refer to the probable cause of the Glacial period, we shall also see the origin of the flood. It is, we believe, an accepted theory that the mountain ranges of the globe were formed by the shrinking of the earth's crust. This was caused by the diminishing lava or molten earth within having contracted at length to such an extent as to have been often removed during the globe's rotation on its axis far away from the still self-supporting crust, till a stage was at length reached when the outer crust became so cold that ice gradually formed over all those parts that were furthest from the molten liquid. At the two poles—that is, furthest from the greatest sunshine, as also from the lava (since the latter would be naturally drawn round with the velocity of the equator, and therefore would be furthest from the poles and nearest to the equator)—there was the greatest abundance of ice. After many centuries of this there came a time when the crust could no longer support itself; the strain of the internal lava beating loosely within was too great at times; great convulsions shook the earth's surface, the crust breaking in long lines, and forcing up huge mountain ridges covered with gigantic blocks of ice that rose thousands of feet high. The crust, diminished in extent, again touched the molten lava, the ice melted, volcanoes arose, steam escaped from the cracks, the whole range of the Andes poured forth clouds of steam, the earth again became warm. But what then happened? The water that was formed by the melting ice, that had not risen in steam to the clouds, spread at once over the lessened area of the earth's surface; the seas rose in every direction and' chilled the air; and thus the earth's outermost surface also once more cooling somewhat, the vapor or clouds dispersed around descended again in torrents to add to the great sea already spreading between the newly raised and the ancient mountain ranges of the earth. This, then, is the