142 NEW YORK STATE MUSEUM 



Chemical analysis. The following analysis was reported by the 

 Empire State Granite Co. in reply to a request from the State 

 Museum dated in 1904. The analysis was made in the laboratories 

 of Simonds & Wainwright of New York : 



SiO. 66.12 



AI2O3 13.71 



Fe.03 I 



FeO j ^-42 



MgO 1. 15 



CaO 3.45 



Na=0 3.6i 



K.0 4.31 



H2O 87 



S .07 



MnO tr 



99.71 



Physical tests. Compression tests of the granites from this 

 quarry, made by Prof. P. J. Carlin, showed an ultimate strength 

 of 23,500 pounds to the square inch in one sample and 22,900 pounds 

 in a second sample. Gravity and absorption tests by the writer 

 gave: Specific gravity, 2.74; ratio of absorption, .148 per cent; 

 pore space .402 per cent. 



West Point gneiss quarries 



The notable collection of buildings at West Point affords an 

 example of the architectural use of local stone to good advantage, 

 an example that might be profitably followed more frequently per- 

 haps than is usual in this section, although there are not a few 

 instances of the adaptation of native quarry materials to be found in 

 the Highland region. The larger structures at-West Point, including 

 the new chapel, the power plant, riding hall and several others, 

 are built of dark gray gneiss that is found on the side of the ridge 

 to the west of the academy grounds. The quarries are worked only 

 as the need develops from time to time, being used only to supply 

 the local rec[uirements. There are several openings, but the prin- 

 cipal one from which building stone has been quarried of late years 

 is near the north end of the ridge and somewhat above the main 

 level of the academy site. The gneiss is quite fresh at the surface 

 which shows the efifects of glacial erosion in deep scorings and 

 polished surfaces. It is a coarsely jointed biotite gneiss, veined and 

 broken by a more massive granite. The two rocks vary much in 

 proportion from place to place and there is every gradation between 



