Ragnarok : the age of fire and gravel

CAUSED BY CONTINENTAL ICE-SHEETS? 85

Can any one suppose that ice could so discriminate ?

And if it by any means effected this separation of the particles of granite, ndissolubly knit together, how could it perpetuate that separation while moving over the land, crushing all beneath and before it, and leave it on the face of the earth free from commixture with the surface rocks ?

Again: the ice-sheets which now exist in the remote north do not move with a constant and regular motion southward, grinding up the rocks as they go. <A recent writer, describing the appearance of things in Greenland, says:

“The coasts are deeply indented with numerous bays and fiords or firths, which, when traced inland, are almost invariably found to terminate against glaciers. Thick ice frequently appears, too, crowning the exposed sea-cliffs, from the edges of which it droops in thick, tongue-like, and stalactitic projections, until its own weight forces it to break away and topple down the precipices into the sea.” *

This does not represent an ice-sheet moving down continuously from the high grounds and tearing up the rocks, It rather breaks off like great icicles from the saves of a house,

Again : the ice-sheets to-day do not striate or groove the rocks over which they move.

Mr. Campbell, author of two works in defense of the iceberg theory— Fire and Frost,” and ‘‘ A Short American Tramp”—went, in 1864, to the coasts of Labrador, the Strait of Belle Isle, and the Gulf of St. Lawrence, ‘for the express purpose of witnessing the effects of icebergs, and testing the theory he had formed. On the zoast of Labrador he reports that at Manly Harbor, where

* “ Popular Science Monthly,” April, 1874, p. 646.