Manhattan Island Geology | Gratacap: Geology of New York City Page 41



	MANHATTAN ISLAND	31

	This hill possessed considerable elevation, and from its dome, Cozzens, reviewing his boyhood recollections, says, " was seen the bay, with the hills of Staten Island still further to the south; then turning to the west the " noble Hudson," with the Newark mountains in the distance, the farmhouses and country seats of the island, and that stupendous work of nature, the Palisades, on the north, and on the east the high ridge of that fertile plain, Long Island."* West of Broadway to 4th Street a range of hills extended, apparently similar in character to the cobble-stone heaps that prevail in and around Brooklyn to-day. These hills were remarkable for the abundance of quail and woodcock found in their shelters. The section about Corlears Hook, the triangular point which covers the eastern terminus of Grand Street to Front and west to Division, was broken by undulating surfaces, and some of the hills were of marked altitude, as high as eighty feet, and were remarkable from the presence of large boulders, which were more numerous here than over the rest of the island. Murray Hill, a flexure of gneiss, to-day is a noticeable protuberance, swelling with a gradual rise from 34th Street, sinking towards 42d Street, and reaching from Lexington Avenue to Broadway, with an imperceptible prolongation northward, melting into the surfaces of Central Park. Here, at 42d Street and 5th Avenue, at Reservoir Park, a hill of the rudest and most heterogeneous mixture of stones and gravel and boulders, cemented together into a matrix of almost impenetrable density, existed, crowning the underlying schist. Between such hills, now removed, small water holes, or ponds, existed at favorable junctures, and occasionally a stream or rivulet crept from the higher levels and wore a sinuous course *An interesting observation was made at this spot. A fort had been built at its summit, and in the center of its enclosure a well was formed, which no doubt served its garrison, and indeed supplied water as late as 1800. But as the surrounding hills were lowered, and the immediate vicinity of the well itself on Bunker's Hill was reduced in elevation, the well became quite dry, a significant proof of the surface origin of its supply.