traced everywhere, even to the sea-shore, not only
down to the water's edge, but beneath it, where-ever the harder rocks
have resisted the action of the tides and retain their original
character. In our granitic regions intersected by innumerable trap
dikes, as, for instance, at Nahant, the smooth surface of many of the
rocks, where sienite and trap have been evenly levelled, shows that the
same inexorable saw, cutting alike through hard and soft materials, has
passed over them. In the hills of pudding-stone in the neighborhood of
Roxbury, we have quartz pebbles cut down to the same level with the
softer paste in which they lie imbedded with pebbles of sandstone,
clay-slate, gneiss, and limestone. In the limestone regions of Western
New York and Northern Ohio, about the neighborhood of Buffalo and
Cleveland, the flat surfaces of the limestone are most uniformly
polished, furrowed, and scratched, the furrows often exhibiting that
_staccato_ grating action described in a former article. I have observed
the same traces in the vicinity of Milwaukee and Iowa City, and we know,
from the accounts given by Arctic travellers of their overland
expeditions, that these peculiar appearances of the surface are
characteristic of the rocks in those regions, wherever they are not
disintegrating under the influence of the present atmospheric agents.

Upon these surfaces, through the whole expanse of the country, rests the
drift, having everywhere the characteristic composition of
glacier-drift, and nowhere that of an aqueous stratified deposit, except
when afterwards remodelled by the action of water. But of this
stratified drift I shall have occasion to speak more in detail
hereafter. There is, however, one circumstance, of frequent occurrence
along our New-England shores, requiring special explanation, because it
is generally misunderstood. Along our sea-shore, and even within the
harbor of Boston, at the base of the harbor-islands, as well as at the
outlet of our larger Atlantic streams, numbers of boulders are found of
considerable size; and this fact is often adduced as showing the power
of water to transport massive fragments of rock to great distances, the
mineralogical character of these boulders being frequently such as to
show that they cannot have originated in the neighborhood of their
present resting-places. But a careful examination of the surrounding
country, and a comparison of the nature and level of the drift on the
ma