DESCRIPTION 



NEW YORK OR MANHATTAN ISLAND. 



Plate 1, Fig. 1. 



This island is about 13 miles long, in a straight 

 line, from the point of the Battery to Kingsbridge ; 

 but by the old road, with all its windings, it is 15 

 miles. It consists of eight different series or for- 

 mations of rock as follows : 



1st Granite. — (See Map and Section, plate ^ifig- 

 1 fy 2, marked 1.) This begins to show itself at 

 28th Street, a little east of the 8th Avenue, and runs 

 in an interrupted line to the North river at 32nd 

 Street, from thence, it is seen between the 10th 

 Avenue and river, and parallel with the river, to 

 60th Street ; it then crops out again at 86th Street, 

 between the " Harlem Railroad Tunnel" and the 

 " Receiving Reservoir" of the Croton Water 

 Works : in levelling east 22nd Street, near, and 

 south of the " Bellevue Alms House," it was expos- 

 ed in two places in a pyramidal form, the top of 

 which was cellular, and had a spongy appearance, 



