Report issued by the U.S. Bureau of Mines discussing copper leaching in the Western United States. As stated in the introduction, "the purpose of this report is to describe and discuss the different leaching and recovery methods currently employed in the production of copper from low-grade ores in the Western states" (p. 1). This report includes tables, illustrations, and photographs.

Report issued by the U.S. Bureau of Mines discussing the building material, dimension stone. As stated in the introduction, "the pertinent properties and principal specifications for stone are described along with exploration, mining, finishing, and use technology. A brief history and geologic background are also included" (p. 2). This report includes maps, tables, illustrations, and photographs.

From Abstract: "This bulletin traces the development of high-pressure, coal and tar hydrogenation technology, based on intensive review of the pertinent literature. The bulletin was written as a part of the Bureau of Mines research program on synthetic liquid fuels. It covers the history and economics of the process; the chemical aspect of hydrogenation of coal, tar, and middle oil; the engineer aspect of converting coal and tar to liquid fuels, principally gasoline; and the equipment of the process."

Report meant to promote health and safety in tunneling and related operations. All precautionary measures recommended are based on actual conditions observed from investigations of fatal or serious accidents and from research conducted to find ways and means of alleviating hazards.

Report issued by the Bureau of Mines over studies conducted on the composition of crude oil. As stated in the abstract, "this publication summarizes the literature on the composition of petroleum, with special emphasis on naphtha and gas oil, and provides a source book for the known qualitative and quantitative facts on crude oil composition" (p. 1). This report includes tables, and illustrations.