ion. There can be little doubt that such traces
exist, and as soon as the so-called _parks_ between Pike's Peak and Long
Peak are explored, we may hope for information on this point. Indeed,
the investigation may be spoken of as already undertaken; for among the
exploring parties now on their way to that region are some intelligent
observers who will not fail to make this point a subject of special
study. But it is well known that the usual characteristic marks of
glaciers extend over the whole surface of the land in the eastern half
of the continent, from the Atlantic shores to the States west of the
Mississippi, and from the Arctic Sea to the latitude of the Ohio, in its
middle course, while within the range of the Alleghanies they stretch as
far south as Georgia and Alabama. In no other region where these traces
have been observed do they extend over such wide tracts of country in
unbroken continuity, this being of course owing to the level character
of the land itself.

The continent of North America, east of the Rocky Mountains, is, indeed,
an immense uniform plain, intersected from east to west only by the
ranges of low hills running in the direction of the St. Lawrence and the
Canadian lakes, and from northeast to southwest by the Alleghany range
stretching from Alabama to New England, where it trends towards the
Canadian hills in the ridges known as the Green and White Mountains.
This coast-range has a short slope towards the Atlantic, and a long one
in the direction of the great Mississippi valley. With the exception of
some higher points of the Alleghany range, the surface of this whole
plain is glacier-worn from the Arctic regions to about the fortieth
degree of northern latitude, the glacier-marks trending from north to
south, with occasional slight inclinations to the east or west,
according to the minor inequalities of the surface. There is, however,
no decided modification of their general trend in consequence of the
range of hills intersecting them at right angles for nearly the whole
width of the continent between latitudes forty-six and fifty; indeed,
the Canadian, or, as they are sometimes called, the Laurentian Hills,
formed a no more powerful barrier to the onward progress of the immense
fields of ice covering the continent than did the small hummocks, or
_roches moutonnees_, in the Swiss valleys to the advance of the Alpine
glaciers. In fact, these low hills may be considered as a succession of
_ro