720 NEW yoke; state museum 



The buff burning or lower clay is distinctly marly in its char- 

 acter. As might be expected, it takes only 18.50^ water to work 

 it up, but still is quite plastic. The air shrinkage is 6^, and at 

 cone .08, 5^. The clay vitrifies at cone 1 with 14/^ shrinkage, and 

 becomes viscous nearly at cone 2. It burns bufc, but with viscosity 

 this passes into greenish yellow. The tensile strength ranges from 

 95 to 110 pounds a square inch. The clay contains .7^ soluble 

 salts. 



Rochester J Monroe co. The Rochester brick and tile manufac- 

 turing CO', is on Monroe street, at the eastern end of the city. Ad- 

 joining this is the German brick and tile co. The clay is reddish 

 in color, 4 to 5 feet thick and underlain by hardpan. Lime pebbles 

 occur in the lower portions. Molding sand is obtained from a neigh- 

 boring eskar. 



The following is an analysis of this clay. 



Silica 50.55 



Alumina 15.46 



Peroxid of iron 4.38 



Lime 10 . 95 



Magnesia 3.35 



Alkalis 6.30 



90.99 



The whole flat area to the west and northwest of the yards was 

 formerly underlain by clay, but so much of it has been dug over 

 that the pit is now nearly a quarter of a mile from the works. The 

 section in the present clay pit involves: 



Loam 18 inches 



Sandy clay 2 feet 



Tat clay 4 feet 



Hardpan . . . 



