Pennsylvania Pulverizing Co. v. Butler

WOOLLEY, Circuit Judge.

Pennsylvania Pulverizing Company is engaged in the business of grading and pulverizing sand for commercial purposes. The process, shortly stated, is to dig from a pit free silica sand such as is found on, beaches by the sea. A portion of this raw product is sold for building purposes and for use by railroad locomotives and foundries. For practically all other purposes the sand must be converted into its relatively pure crystalline form; therefore the balance is washed over concentrating tables to eliminate fine partieles and impurities. The residue, now pure silica but…