changes
are in operation along the bulkheads of the Harlem River, as seen from
High Bridge or Washington Bridge, and more noticeably at Morris Docks,
Kingsbridge Village, and the environs of the ship canal at Marble Hill.
Besides
such contrasted conditions affecting the marginal topography of
Manhattan Island, and prevalent eighty years ago along its shores, the
surface of the island presented a widely different aspect from what we
see to-day, and it would be difficult to re-invest the slightly
undulating grades of the present streets and avenues with the hilly and
abruptly sloping or softly rounded elevations that rose above the
tidewater of the bay one hundred or one hundred and thirty feet in
the, at present, lower portion of the city. It was, indeed, a manifold
mound of drifted material, a surface formation of gravel, stones, sand
and earth, sculptured by streams and interrupted by natural
subsidences or dips in the underlying" rocks, which the engineering
requirements of the city encountered as the population steadily moved
northward in its peaceful conquest of this wild and beautiful region.
Before
reviewing some of these ancient conditions, the knowledge of which is
necessarily serviceable in any study of the geology of Manhattan
Island, it conveys a pleasant surprise to read this characterization
by Mrs. Lamb of the picturesque natural features of its surface.
"
Manhattan's twenty-two thousand acres of rock, lake, and rolling
table-land, rising in places to an altitude of one hundred and
thirty-eight feet, were covered with sombre forests, grassy knolls,
and dismal swamps. The trees were lofty, and old, decayed and withered
limbs contrasted with the younger growth of branches, and wild flowers
wasted their sweetness among the dead leaves and scant herbage at their
roots. The wanton grapevine swung careless from the topmost boughs of
the oak and the sycamore, and blackberry and raspberry bushes, like a
picket guard, presented a bold front in all the possible avenues of
approach."
As early as 1621 there is definite information that fruits,
