A GEOLOGICAL HISTORY. 13 



This Carbonate of Lime has many small specks of 

 Serpentine diffused through it, and forms a kind 

 of " Verd antique," which, when polished, makes 

 handsome specimens. At this locality formerly, 

 at a considerable expense and labour, many exca- 

 vations were made in search of the precious me- 

 tals ; the seekers allowing themselves to be de- 

 cieved by the glitter of the golden and silvery 

 Talc, through the Serpentine. 



4th Gneiss. — (See Map and Section, plate I, Jig. 1 

 <fy 2, marked 3.) This rock has a greater extent, 

 and shows itself more than any other on this 

 island ; it begins at the Battery, which it underlies, 

 and a few years ago showed itself by an out-crop 

 on one of the walks, but it has been levelled and 

 buried, in making improvements, on that most 

 delightful of spots ; it was to be seen also (until 

 lately) at the lower end of east 14th Street, near 

 the river, but this was also buried, by levelling 

 that part of the city : in 8th Street, west of the 3d 

 Avenue, in digging a well, it was found about 18 

 feet below the surface. In boring for fresh water 

 at Disbrow's Blacksmith's shop in Bleecker street, 

 between Broadway and Mercer street, after passing 

 through some 500 feet of Gneiss, the Granite was 

 reached. The first or nearest place where it is 

 now to be seen, is at 22nd Street, near the 8th 



