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 marks 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. The Sierra
scorings are largely local. So much for striae; we perceive their
universal presence and their marked reference to the north, or to
elevated regions which dominate our level plains.
The
second feature of this epoch, designated by common consent, the Drift,
is a series of surprising facts, showing, through 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
strewn over hills and moors where no rock lies in place, sunken in the
soil where the lithology of the soil is entirely distinct, while that
of the monoliths themselves is identical with rocks many miles
northward. Gigantic boulders—Titanic mementoes of the past— are
scattered over Central Europe, over Germany, Holland, and Russia. They
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 preadamite Antaeus. 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
