This folder contains correspondence and other documents relating primarily to activities at the Stewartsville works. Most of the letters are to or from Edison, Walter S. Mallory, Emil Herter, William H. Mason, and John F. Randolph. There are also letters by Herman E. Kiefer and Frederick Siefke. Much of the correspondence with Edison concerns prospecting and other operations at Stewartsville. One letter by Edison, probably written in June 1906, pertains to oil leaks and includes a drawing. A few items deal with gas leaks; experiments with cement kilns; and tests with the gypsum feed. Other documents relate to the analyses of chalk and coal; calculations of unrecovered dust; and an experiment with rice coal. Also included is material regarding company finances, foreign competitors, customer relations, product quality, and the company's sales agency, Pilling & Crane. A few items pertain to photographs of Edison and to inquiries about Edison's crushing rolls.

Less than 10 percent of the documents have been selected. The unselected material includes summaries of operating costs and output at the Stewartsville works; reports on prospecting; and analyses of lime and magnesia samples.