CLAYS OF NEW YORK 839 



that from the quarry one mile nortli, and is used by the Alfred clay 

 CO. for the manufacture of roofing tile and dry press brick. 



Ilornellsville, Steuben co. The shale at this locality frequently 

 contains interbedded layers of sandstone, which are separated in 

 mining without much trouble. The shale is rather gritty, and on the 

 addition of 20;^ of water gave a lean, workable paste, which shrunk 

 2.7^ in drying and 5.3^ in burning. The tensile strength of the 

 air-dried mud to the square inch was on the average 34 pounds, with 

 a maximum of 39. 



Incipient fusion occurs at cone .06, vitrification at cone .01, vis- 

 cosity at cone 4. 



The shale burns to a dark red. It is used in the manufacture of 

 paving brick. 



The composition of the clay, from, an analysis furnished by the- 

 Preston brick co., is as follows: 



Silica 64.45 



Alumina 17 . 7Y 



Ferric oxid > 7 . 04 



Lime .58 



Magnesia 1.85 



Potash 2.52 



Soda 1.95 



96.16 

 Pluxes 13.94 



The method of manufacture followed at these works consists of 

 the usual drji pan for grinding the shale and wet pan for tempering 

 it. The molding is done by a stiff mud, side-cut machine, and the 

 green brick are repressed. The burning is in down-draft kilns. 



Coryiing. A gray, gritty shale is quarried at this point for the 

 manufacture of paving and building brick. The quarries ar& 

 located along the Erie railroad, about half a mile west of town.. The 



