34 



NEW YORK STATE MUSEUM 



supply rock of lighter colors, suitable for the manufacture of 

 calcined plasters, but only the latter company engage in their manu- 

 facture. The American Gypsum Co. sells its output in crude form 

 mainly to cement mills. The plan and mines of the Akron Gypsum 

 Products Corporation were taken over in 191 5 by the American 

 Cement Plaster Co. The continuation of the gypsum deposits is 

 found to the west of Akron, as shown by explorations with the drill 

 made a few years ago. There are records of the- occurrence of 

 white gypsum under the city of Buffalo, but owing to the large 

 flow of water that is encountered in the beds there has been no 

 attempt put forth to develop the deposits. 



The production of gypsum for 1914 and 191 5 is shown in tlie 

 accompanying table, which also gives the several forms in which it 

 was sold by the mining companies. Considerably more than one- 

 half is converted into calcined plasters by the latter. A few thou- 

 sand tons are ground for land plaster, and the remaining is sold 

 crude to portland cement works or to calcining mills outside of 

 the district. There is some fluctuation from year to year in the 

 relative proportions of mined product and the amount of calcinei 

 plasters, as the mining companies often hold considerable amounts 

 of rock in stock. The production of calcined plasters from foreign 

 rock is not included in the statistics. 



Production of gypsum in New York 



IRON ORE 



The iron mining industry reversed its course last year and showed 

 a marked improvement in activity as compared with the record for 

 1914. The latter year was a period of great depression for the 



