From Introduction: "The present bulletin presents analyses and descriptions of samples collected during the fiscal years 1916 to 1919. In order that the material in this bulletin may be used to supplement that presented in Bulletins 22, 85, and 123, the same plan of geographical classification has been followed, the analyses and descriptions of the samples being grouped in alphabetical order according to the State, country, and town near which the mines or prospects sampled are situated."

Annual report of the director of the U.S. National Bureau of Standards discussing the staff, facilities, and activities of the agency during the fiscal year 1921-1922.

From Introduction and Reason For Undertaking the Work: "The Bureau of Mines has recently made up experimental heats of alloy steels for the Army and Navy. The Bureau of Mines has analyzed the Army steels for its own guidance only, for analysis of the steels for the arsenal was also scheduled to be made by the arsenal, though it was not, as it happened."

From Introduction: "Part of I of this paper cover the engineering and economic side of the industry; the other phases of the investigation which have been under the direction of G. St. J. Perrott, of the Pittsburg station of the United States Bureau of Mines, are discussed in Part II."