Page:Popular Science Monthly Volume 12.djvu/336

322 the country, and losing themselves in the sea along the coast, while they corrugate the borders of the innumerable bays, and the walls of the deep fiords that indent the shores. These furrows can be traced for miles across the country, cutting the three ranges that lie between Bangor and the sea almost at right angles, traversing these highlands as though they were level surfaces, dipping beneath the sea, and reappearing upon the sides of Mount Desert, to be again lost in the waters of the Atlantic. Unquestionably, over that sea-floor, could we follow their tracks, the same furrows continue to the verge of the continent which lies miles out to seaward, when the steep edge of the land falls precipitately to the true bottom of the ocean. Over the West, throughout Canada, and upon the ancient rocks of the Great Lakes, these evidences of past erosion exist upon an enormous scale. As a rule, these striæ indicate a planing surface advancing from the north, and, though a second series may occur, as upon the islands of Lake Erie, from east to west, whose furrows obliterate the first inscription, such phenomena are local merely, and infrequent. Again, upon the Sierras, the tops and declivities of the ranges are scored and engraved with the indelible signatures of past erosions, and the rocks of the barren wastes of British America are. signalized in the same manner. So much for striæ: we perceive their universal presence, and their marked reference to the north, or elevated regions which dominate over level plains.

The second feature of this epoch, designated by common consent the Drift, is a series of surprising facts, evincing, throughout all this deeply-scored and paneled country, the past presence of extraordinary transporting agencies. We find rocks of enormous size, in some instances weighing 3,000 tons, planted in fields and lowlands, or strewed over hills and moors, where no rocks lie in place, sunken in the soil where the lithology of the district is entirely distinct, while that of the monoliths themselves is identical with rock many miles northward. These gigantic bowlders, Titanic mementos of the past, are scattered over Central Europe, over Germany, Holland, and Russia, are identical in character, and can have no nearer origin than in the mountains of Scandinavia. Some of these blocks of stone are of incredible dimensions, and are accompanied by innumerable smaller ones that lie over these districts as if flung in sport by some pre-Adamite Antæus. They have served the most useful purposes in the flat countries through which they are found, being used for buildings of every description, and their smallest associates have helped to pave the highways between Hamburg, Magdeburg, and Breslau. Accredited in ruder times to the malevolent agency of man's spiritual foes, they were called devil-stones; but Science, recognizing their distant origin, has named them erratics, and the Germans, more picturesquely, wanderers. Not only are they found upon level and loamy lands, utterly unaccountable except by the assumptions of