830 NEW YOEK STATE MUSEUM 



says Prof. Hall, " are a green and ashen marl, with seams of fibrous 

 gypsum and red or transparent selenite. It occurs in the vicinity 

 of LyoDs and numerous points farther west ". 



The third division contains large gj^psum beds and is probably not 

 suitable for use. 



The Salina shale, as stated above, is worked at Warner, Onon- 

 daga CO., by the Onondaga vitrified brick co. The shale as exposed 

 in their bank consists of a green or red, soft, argillaceous shale, 

 of considerable impurity, as the following analyses furnished by 

 the company show. 



Calcareous Red Blue 



layer in bank shale shale 



Silica 25.40 52.30 ^ 5Y.Y9 



Alumina '9.46 18.85 16.15 



Ferric oxid 2.24 6.55 5.20 



Lime 22.81 3.36 2.73 



Magnesia 10.39 4.49 4.67 



Carbonic acid 20 . 96 3 . 04 3 .42 



Potash 95 4.65 4.11 



Soda 1.35 1.22 



Water and organic matter 7. 60 5.30 4.50 



99.81 99.89 99.79 



Total fluxing impurities.. . 36.39 20.40 17.93 



These shales must be quite fusible owing to their high per- 

 centage of fluxing impurities. 



At the works of the Onondaga vitrified brick co., the shale crops 

 out in considerable thickness near the yard, and is of various shades 

 of red, green, and gray; it disintegrates very rapidly, and the whole 

 bank is traversed by numerous cracks, so that a small blast brings 

 down a large amount. The material is mixed with a surface clay 

 in the proportion of 1 of clay to 3 of shale; it is ground in a dry 

 pan, and molded in an auger machine; the green bricks are dried 

 in tunnels and burned in circular kilns; the product is of a red color, 

 and very hard. 



Marcellus shale. This formation presents numerous undesira- 

 ble features, so that its occurrence is of little importance to clay 



