PHYSICAL TESTS OF BUILDING STONES 353 



V. 



PHYSICAL TESTS AND CHEMICAL EXAMINATIONS 



OF BUILDING STONES. 



A series of physical tests of the representative building 

 Stones of the state was undertaken for the purpose of ascer- 

 taining what their comparative values were for durable con- 

 struction work. Chemical determinations were made of 

 the amounts of certain constituents, which were supposed 

 to be Injurious or which were indicative of a composition 

 liable to attack, on long-continued exposure to atmospheric 

 agencies, and, also, of those which, by their presence in cer- 

 tain associations, might explain the structure of the stone 

 as determined by its cementing or binding material. 



The stones were selected with especial reference to their 

 value and the extent to which they were used in building 

 and general constructive work. So far as possible, all the 

 great classes of stone and the larger quarry districts of the 

 state are represented. The granites of Grindstone island, 

 Jefferson county, and of KeesevIUe, Essex county, repre- 

 sent the developed quarries in the northern part of the 

 state. The marbles of Tuckahoe and Pleasantville are 

 from the Westchester marble district. The Glens Falls, 

 Plattsburgh and Gouverneur stones represent the marbles 

 of the northern counties, so far as they are worked to ex- 

 tent ; the calciferous sandrock and magnesian limestone are 

 represented by the Sandy Hill limestone; the limestones of 

 the Mohawk valley are represented by those from Tribes 

 Hill, Canajoharie and Prospect ; the St. Lawrence valley 

 by the Chaumont stone ; the Onondaga gray limestone by 

 a specimen from the Reservation quarries ; the eastern 

 Upper Helderberg formation by the Coblesklll stone ; the 

 Upper Helderberg limestones of the western-central coun- 

 45 



