144 NEW YORK STATE MUSEUM 



A second deposit has recently been opened up, about 6 feet 

 below the first, which is said to show over 90^ gypsum. 



Oakfield. Two companies, the United States Gypsum Co. and 

 the Oakfield Plaster Manufacturing Co., are engaged in mining 

 and calcining gypsum at Oakfield. 



The United States Grypsum Co. is the larger of the two and 

 operates the mines and mills formerly worked by the English 

 Plaster Co. and the Genesee Plaster Co. This company was 

 formed in the winter of 1901-2 and controls factories in Michi- 

 gan, Iowa, Kansas and Oklahoma as well as New York. In addi- 

 tion to the plants mentioned above, the Buffalo Mortar Works 

 and the Big Four Wall Plaster Co. were taken into the combine. 



For many years Mr Olmsted mined gypsum and manufactured 

 land plasiter at Oakfield, and about 1892 he put in one kettle to 

 make plaster of paris. So far as is known, this was the first 

 attempt to calcine New York gypsum on a large scale, and it 

 was successful from the outset. Subsequently the property was 

 purchased by the English Plasiter Co., and a new plant was 

 erected. The equipment of this mill consists of one Blake 

 crusher, one nipper, five kettles and five burstone mills. Two 

 mines supply the rock for this mill. These mines are about 40 

 feet deep, and the rock is hoisted by steam power. The bed of 

 gypsum is only about 4 feet thick, but it is said that about 80 

 feet below this deposit is another bed about 10 feet thick, but 

 this has not been developed^ nor is anything known concerning 

 its quality. 



Water gives a great deal of trouble in the mines, and one of 

 them has to be abandoned in the winter because of the difficulty 

 and expense of pumping the water. Howell twist drills are used 

 to make ready for the blasts, and black powder is the explosive 

 used. 



The mill formerly owned by the Genesee Plaster Co. is the 

 most convenient one in the State using the kettle process. To 

 the regular calcining equipment has been added the machinery 

 of the Big Four Plaster Co., which was formerly located in the 



