It is, perhaps, easy to suppose that such world-cloaks might have
existed; we can imagine the water of the seas falling on the
continents, and freezing as it fell, until, in the course of ages, it
constituted such gigantic ice-sheets; but something more than this is
needed. This does not account for these hundreds of feet of clay,
bowlders, and gravel.

But it is supposed that these were torn from the surface of the rocks
by the pressure of the ice-sheet moving southward. But what would
make it move southward? We know that some of our mountains are
covered to-day with immense sheets of ice, hundreds and thousands of
feet in thickness. Do these descend upon the flat country? No; they
lie there and melt, and are renewed, kept in equipoise by the
contending forces of heat and cold.

Why should the ice-sheet move southward? Because, say the
"glacialists," the lands of the northern parts of Europe and America
were then elevated fifteen hundred feet higher than at present, and
this gave the ice a sufficient descent. But what became of that
elevation afterward? Why, it went down again. It had accommodatingly
performed its function, and then the land resumed its old place!

But _did_ the land rise up in this extraordinary fashion? Croll says:

"The greater elevation of the land (in the Ice period) is simply
assumed as an hypothesis to account for the cold. The facts of
geology, however, are fast establishing the opposite conclusion,
viz., that when the country was covered with ice, the land stood in
relation to the sea at a lower level than at present, and that the
continental periods or times, when the land stood in relation to the