LIME AJ^D CEMEN^T INDUSTRIES 831 



Magnesia 21.25 20.71 



Carbonic acid 47.3 46.66 



Perric oxid , .21 .21 



Water .02 .16 



Silica .24 , 



Alumina .19 



Loss • • • .63 



100 99.75 



The Tnckalioe marHe co.'s quarry is f of a mile to the north. * 

 The quarry is about 400 feet long and 40 feet deep, and np to the 

 present time the stone has been nsed for building purposes only. 



Still farther to the north about ^ oi sl mil© is IlTorcross Bros.' 

 quarry. The rock is similar in character to the preceding but the 

 quarry is smaller. 



The quarry at Pleasantville is the largest in Westchester 

 county. It is operated by O'Connell & Hillery, successors to the 

 Cornell lime co. The limestone is very uniform in its character, 

 andj on account of its white color and coarsely crystalline char- 

 acter, has been called " snowilake marble.'' E'early the entire 

 production of this quarry is used for the manufacture of marble 

 dust. The composition of the rock, according to an analysis 

 given in the 16th annual report of the United States geological 

 survey, pt 3, p. 468, is as follows: 



lime carbonate 54 . 62 



Magnesium carbonate , 45 . 04 



Iron carbonate ., .16 



Alumina .07 



Silica , .1 



99.99 



