Construction of the Blake Stone Crusher. ... the 15- by 9-in. machine had a capacity of about 20 tons an hour of ore, broken so that the largest pieces passed a 4-in. ring; the medium size a 1.75-in. ring, and the fines through a screen of 0.75 in. In a description by A. J. Bowie, Jr., of the Father de Smet gold-mill, where the 15- by 9-in ...