In caverns near Liège, France, human bones have been found, with the cave-bear, elephant, rhinoceros, and other species now extinct. Skulls found in these primeval caves, especially one near Düsseldorf, called the "Neanderthal," "is the most brutal of all known human skulls, resembling those of the apes." These rude men probably were living at the same time, or even later, than the makers of the "refuse heaps" of Denmark.
Wales has been under the sea to the depth of fourteen hundred feet, as proved by glacial shells; its submergence and reëlevation would require, by careful computation, about two hundred and twenty-four thousand years.
Lyell showed that the Alps, Andes, and Himalaya Mountains were all elaborated under water. "The Alps have acquired four thousand, and even, in some places, more than ten thousand feet of their present altitude since the commencement of the Eocene (dawn of recent) period.... It is not too much to say that every spot which is now dry land has been sea at some former period, and every part of the space now covered by the deepest ocean has been land. The present distribution of land and water encourages us to believe that almost every conceivable transformation in the external form of the earth's crust may have been gone through. In one epoch the land may have been chiefly equatorial; in another, for the most part polar and circumpolar."
Lyell showed also the great age of the world by the changes which have taken place in climate. In Greenland are a multitude of fossil plants, which show that it formerly enjoyed a mild and genial climate. Fossil tulip and walnut trees have been found within the Arctic circle.
"On the North American continent, between the Arctic circle and the forty-second parallel of latitude," said Lyell, "we meet with signs of ice-action on a scale as grand, if not grander than in Europe." The drift covered from the Atlantic border of New England and Labrador westward to Dakota and Lake Winnipeg, and farther north, across the continent. Some stones in this bed of ice were thirty feet square, weighing over four million pounds. Some boulders from the Alps, weighing three thousand tons each, are now found on the Juras. "It must, I think," said Lyell, "be conceded that the period required for the coming-on of the greatest cold, and for its duration when most intense, and the oscillations to which it was subject, as well as the retreat of the glaciers and the 'great thaw,' or disappearance of snow, from many mountain-chains where the snow was once perpetual, required not tens, but hundreds, of thousands of years."