The depressions of the lowlands beneath the sea are accounted for in the great upheavals. On an average, rock weighed out of water is one and two-thirds times as much as when weighed under water. All the strata of mountains and plateaus lifted from beneath the waters weigh one and two-thirds times what they did before being disturbed.
Geologists tell us that the Earth’s crust was depressed six to seven thousand feet. This would enable the ice to flow over the surface, the bergs being of enormous depth. The lowlands of every continent have been thus plowed. The evidence exists in every valley and far up the sides of all mountains. This evidence is by no means confined to scratches on the rock, but the water-washed gravel and polished pebbles equally attest its action. You can hardly sink a shaft in valley or hill without encountering them. With the present inclination of the Earth’s pole to the elliptic no such quantity of ice can possibly occur. No iceberg has ever yet been seen in tropical waters. There never yet has been enough at one time within historic note, to counteract the influence of the Gulf Stream about Norway and Iceland.
How different the ancient drift! Then the ice penetrated all open seas, caused by submergence. It plowed alike the Brazilian mountains, the Sierra Nevada, and the Appalachian. It chilled the seas to the very center of the submerged hemisphere; and England witnessed the dwelling of the reindeer in her borders, while it lasted. According to Sir Chas. Lyell, the temperature sank from the uniformity of our intensely warm climate to the chilliness of melting ice. The cold was now as uniform as the heat had before been constant. The north pole, pointing directly to the sun, would bring the whole land hemisphere within perpetual sunshine; and consequently, when above the sea, would be in a tropical or semi-tropical zone to the very edge. This climate would continue as long as the land could hold back the ice, which had been accumulated at the equator. But no sooner did the lowlands become submerged, than the ice would change the climate, wherever it could in large quantities accumulate. As it plowed every river, plain, and gulch, the fauna, adapted to the former climate, would naturally lose their existence. Such is the history of the drift. Ninety-seven per cent. of all land animals died. By the slow process of disintegration of the mountains, the hemisphere was again raised, and its former beautiful climate restored.
Section 4.
How was such a World adapted to Man or strictly speaking,
Man to such a World?
1. The even climate of such a world would tend to his longevity, and be most genial to his feelings.
Man’s nature calls for an even climate. Now by art he tries to even up the climate of the year.
(1.) Less than two-thirds of the lighted hemisphere could have been covered with dry land. Many bodies of water are known to have been included within the areas of land. The pole, pointing directly toward the sun, must have been near Gibraltar. Allowing that land extended in every direction, four thousand miles or more, we should then have an open sea of from fifteen hundred to two thousand miles, intervening between the edge of the hemisphere of land, or perhaps more properly, the quartosphere of land, and the region of perpetual ice.
(2.) On the sunny side of such a globe, being at first entirely water, a rapid evaporation must have taken place; and most, nearest the north pole. This would give rise to currents, both of air and water, to flow toward it, as a source of supply. Counter currents of both would follow. Currents of either starting near the equator would be cold and possess a motion greater than the earth, a few degrees toward the pole. This would send both towards the northeast, until meeting the return currents of wind, which would cause variable winds; but a most genial climate must have surrounded the earth, at least forty degrees wide.
(3.) Such a climate, with such facilities for evaporation, would provide the way for perpetual harvest. The open sea to the edge must have been constantly filled with floating ice. Cold breezes, often laden with thick fog, would float in over the edge of the land. This may account for the long hair which covered the mammoth elephant of Siberia and California. No winds are more penetrating than those coming from large bodies of melting ice; yet under a perpetual sunshine the vegetation must have been abundant.
2. We add by way of recapitulation: