TH^ MINING AND QUARRY INDUSTRY I915 



Value of production of pottery 



25 



CRUDE CLAY 



The total value of crude clay produced during the season of 191 5 

 amounted to $28,684. This was the value placed on 13,745 tons 

 of which 11,012 tons were sold for slip clay. During the preceding 

 season the entire output of slip and red burning clay amounted to 

 /'109 tons with a value of $12,424. There was no production of 

 white or buff burning clay during 191 5. 



Owing to the scarcity of aluminum sulphate . for use in water 

 filtration plants, there was some discussion locally of the utilization 

 of the comparatively high alumina clays of the Hudson River 

 region for the purpose of manufacturing this chemical. At the 

 present time the greatest demand for slip clay comes from the 

 electric porcelain manufacture. It is also used to a great extent 

 as a bonding material in the manufacture of artificial abrasive 

 wheels. In both the abrasive and slip uses it is necessary that the 

 clay should have a quiet fusion and be free from bubbles when 

 cooled. Such clays are found in this State at a few localities near 

 Albany and Troy. 



There are four known beds of clay in the Albany region which 

 have furnished material suitable for slip and bonding purposes. 

 The lowest has a thickness of about 8 feet and is fairly uniform in 

 most exposures. At some localities this bed is of. rather irregular 

 deposition and composition. The result is that material of uncertain 

 working qualities is sometimes produced. The next higher bed with 

 a thickness of about 4 feet has furnished a great amount of fine 

 slip but at present is not exposed so as to be available for produc-. 

 tion. It is from this bed that the early production was made. The 

 third bed, which is the main producing one at present, has a thick- 

 ness of about 14 feet and is very regular in composition and 

 structure. Immediately above this is found a 2 foot bed of gray 



