Manhattan Island Geology | Gratacap: Geology of New York City Page 42



	32	GEOLOGY OF NEW YORK CITY

	to the east or west, emptying into Hudson River or the East River channel. Such was the " Minetta water,"' running into Bollus Pond at Dowling Street, also the ditch that connected a little pond in Manhattan Square with the present large lake in Central Park and escaped thence to the East River, also the stream that fed Harlem Lane, about 130th Street on the west side, and the larger creek and streamlets at its heads, running into Hell Gate at 92th Street. Reverting now from this somewhat reminiscent and historical survey of these surface characters, which reveal the original topography of the more altered areas of the island, and are more naturally pertinent to its lower sections, we will look northward and decipher the constructional lines north of 59th Street, without regard to its geology, only aiming at a general sketch of its relief. The process of grading and leveling and creating the orderly adjustments of a city has reduced the exceptional elevations, and only in the yet northern portions, or in the natural contours of Central Park, are the uneven surfaces preserved, while in Central Park they are greatly masked. The bosses of rock west of the park (Fig. 3), north of 59th Street, have been largely removed, but sections showing their former height are here and there preserved, and the rock faces within the Central Park wall, along 8th Avenue, exhibit their nature. Besides a succession of barren folds of rock, holding pockets of debris, there were deep basins and valley-like pits between them, as late as 1880, holding the hovels and huts of a Bohemian domiciliary and of gardeners and squatters. The east side of the city was more thoroughly reduced to order before the west side, and showed only in isolated squares the bluffs of rock standing vertically over the streets cut through them, as between 3d and 5th Avenues above 90th Street. A base leveling, as it were, has been instituted, and except for the unavoidable undulations of the surface, its superficial characters, of course, have disappeared. On the west side, in the region of Claremont, now 116th Street to