Page:The evolution of worlds - Lowell.djvu/249

Rh supply. And here, as elsewhere, we find prehistoric record in the rocks of a once more smiling state of things, strengthening the testimony we deduce from man. The forests, crowning now only the greater heights, are but the shrinking residues of what once clothed the land. The well-named Arid Zone is becoming more so every day.

If from the land evidence of drying up we turn to the marine, we see the same shrinkage at work. It has even been discovered in a lowering of the ocean bed, but as this may so easily be disputed, we turn to one aspect of the situation which cannot so easily be gainsaid,—the bodies of water that have been cut off. That the Dead Sea, the Caspian, the Great Salt Lake, are slowly but surely giving way to land, is patent. If the climate at least were not more arid than before this could not occur; but more than this, if the ocean were not on the whole shrinking, there would be no tendency to leave such arms of itself behind to shrivel up. That the ocean basins are deepening is possible, but we know of one depletion which is not replaced—evaporation into space; and of another bound to come—withdrawal into fissures when the earth shall cease to be too hot.

This gradual withdrawal of the water may seem an unpleasant one to contemplate, but like most things it has its silver lining in the hope it holds out that sometime there shall be no more sea. Those of us who