CLAYS OF NEW YORK i O i 



Below is given an analysis of the clay. 



Silica 59.05 



Alumina 22.11 



Peroxid of iron 6 . 54 



Lime 2.19 



Magnesia 2 . 64 



Alkalis 6.22 



98. Y5 



The plasticity of the clay is quite well shown by the amount of 

 water required to work it up, yiz, 40^. . The air shrinkage was 8^; 

 when burned at .08, which is about the temperature attained in the 

 scove-kilns, the shrinkage was 9^. At this point, however, incipient 

 fusion had barely begun. When heated above this point the shrink- 

 age increased quite rapidly, so that at vitrification, which occurred 

 at cone 1, the total shrinkage was 16^. At incipient fusion the 

 clay burns red; at vitrification a very deep red. Viscosity occurs at 

 cone 4. The high shrinkage of this clay would probably interfere 

 with its use alone for vitrified wares. The tensile strength of the 

 air-dried briquettes ranged from 133 to 140 pounds a square inch, 

 but one gave a minimum of 108 pounds. The clay contains .7fo of 

 soluble salts. 



Fishers Island, Suffolk co. The extensive deposit of clay at this 

 locality is worked by the Fishers Island brick manufacturing co., 

 whose plant has a capacity of about 15,000,000. The yards are 

 situated on the north shore of the island between Clay point and 

 Hawks neck point. About 1500 feet from the shore is the bank 

 of clay of a reddish color and thinly stratified, the layers of clay 

 being separated by very thin ones of sand. In most places, how- 

 ever, the mass has been disturbed by glacial movements. There 

 is a stripping of 20 or 30 feet of a whitish sand, the finer portions 

 of which can be used for tempering. Their present working face 

 i^ 30 feet above tide at its base, and the clay, it is declared, has a 



