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 said, puzzled mankind for many years. Their existence has long been known: for, even before men dared to venture their lives in the polar regions, navigators, in crossing the Atlantic Ocean, frequently met with these marble-like mountains; and, what is worse, sometimes ran at full speed against them, and were sunk with all on board. Bergs are frequently enveloped in dense fogs, caused by the cold atmosphere by which they are surrounded condensing the moisture of the warmer atmosphere which they encounter on their voyage southward; hence they are exceedingly dangerous to navigation. But now to speak of their formation.

Many of the great valleys of the far north are completely filled up with solid ice. Observe, we do not say that they are merely covered over with ice; they are absolutely filled up with it from top to bottom. Those ice-masses are known by the name of glaciers; and they are found in most of the elevated regions of the Earth,—on the Alps and the mountains of Norway, for instance,—but they exist in greater abundance about the poles than elsewhere.

Glaciers never melt. They have existed for unknown ages, probably since the world began; and they will, in all likelihood, continue to exist until the world comes to an end,—at least until the present economy of the world terminates. They began with the first fall of snow, and as falls of snow during the long winters of the polar regions