Report discussing description of equipment tested to prevent explosions when using coal-cutting explosions and provides explanation of fire damp protection theory.

From Author's Explanation: "This bulletin is intended to include every legislative enactment of the Commonwealth of Pennsylvania relating to the mining and mineral industries. The entire body of mining laws is set out for these obvious reasons: (1) To show the progress and advancement made, and the changes through which the enactments have passed; (2) an author may not assume the determination of what particular laws are in fact in effect, as this is within the jurisdiction of the courts alone; (3) it was at least necessary to set out all acts that had at any time been construed by the courts."

From Prefactory Statement: "In this bulletin are presented the results obtained in the first two phases of the work outlined above. The bulletin is in two parts. The first part describes the methods of mining and milling used, suggests a standard method of sampling finished graphite, and describes a rapid and convenient method of analysis developed at the Pittsburgh station of the Bureau of Mines, to which has been assigned the analytical and microscopic work. The second part describes experiments on the concentration and milling of graphite, which were made at the Salt Lake City, Utah, station."