CJLAYS OF NEW YORK 



843 



ISTo. 1 furnislied by P. H. Kinkel. 



'No. 2 Chemistry of pottery, p. 38. 0. Langenbeck analyst. 



Other quarries occur in the Yicinity of Bedford, on the farm of 

 A. Hobby, and L. McDonald, but their output is not constant. 



Though in New York the quarts: and feldspar are found in the 

 same veins, still at many localities they occur alone, but in every 

 case the vein is found in metamorphic rocks. 



Preparation. The quartz and feldspar are quarried in the usual 

 way by blasting, and after sorting when this is necessary, they are 

 ground in a buhr stone mill, similar to that shown in plate. This 

 reduces the material to a condition of fine sand, after which it is 

 put in a ball mill, with rolled flint pebbles, and ground for about 

 six hours, the resulting product being a very fine powder, which i& 

 shipped. 



Uses of feldspar. Feldspar is used to a large extent as a fluxing 

 material in the manufacture of white earthenware, and porcelain 

 bodies, and is also one of the ingredients of the glaze for hard porce- 

 lain. In addition it has also found some use as a constituent of 

 glass, the feldspar furnishing the necessary amount of alumina for 



« 



the purpose of hardening the product and as a wood-filler. 



Uses of quartz. Quartz is also used as an ingredient of pottery 

 for the purpose of counteracting fire shrinkage, and, in addition 

 to its uses in this direction, powdered quartz finds application in a 

 number of other branches of the industrial arts. Much of the 

 quartz produced in this country is mixed with oil, and is used a& 

 a wood-filler in painting. That utilized for this purpose is ground 

 as finely as the quartz consumed by the potters. It is also em- 

 ployed in the manufacture of sand pa,per, .powders and scouring soaps 

 and glass manufacture. 



The entire output of the quarries at Bedford is hauled to Bed- 

 ford Station, and shipped from there to the potteries at Trenton. 



The prices obtained for both quartz and feldspar vary naturally 

 with the grade of the material, and also the supply and demand. 

 Ground spar at Trenton brings about $7 a ton, while ground 



