GRANITIC ROCKS 375 



river, between Peekskill and Fishkill, there is a fine section of 

 these rocks exposed. 



On the borders of the Adirondack region quarries have been 

 opened in the towns of Wilton, Hadley and Greenfield, in 

 Saratoga county; at Whitehall, in Washington county ; at Little 

 Falls, in Herkimer county ; and near Canton, in St. Lawrence 

 county. The inaccessibility of much of this region and the 

 distance from the large city markets have prevented the opening 

 of more quarries in the gneissic rocks on the borders of the 

 Aclirondacks. 



Description of Granite Quarries. 



New York, Manhattan Island.— The outcropping ledges of 

 gneiss rocks, from Twenty-ninth street (on the west side) to the 

 Spuyten Duyvil creek, and from about Sixteenth street north- 

 wards, on the eastern side of the island, have been cut through 

 and graded down in so many places that a large amount of stone 

 has been furnished, ready for laying up foundations and for 

 common wall work. These gneisses are generally bluish-gray in 

 color, medium fine-crystalline, highly micaceous and schistose in 

 structure. The beds are thin and tilted at a high angle and ia 

 places are in a vertical position. The more micaceous rock is apt 

 to flake and disintegrate on long exposure, especially when the 

 blocks are set on edge. The more feldspathic stone of the 

 granitic veins and dikes and the more hornblendic strata afford a 

 better building material. 



The Croton reservoir, Fifth avenue and Forty second street 

 and St. Matthew's Lutheran church, Broome street, are con- 

 structions of the best of the island gneiss. 



The gneissic rocks have been quarried extensively in the 

 Twenty-third and Twenty-fourth wards, New York city, and in 

 the adjacent southern towns of Westchester county. 



The gray variety of gneiss has been most largely employed 

 for the better class of building. 



New York City, Fordham. — A micaceous gneiss is quarried on 

 the property of St. John's College, on the corner of the Boule- 

 vard and Pelham avenue. It is of a bluish-gray shade of color, 

 and is known locally as " bluestone." The new buildings of the 

 college are constructed of this stone. 



