Abstract: "This report presents a U.S. Bureau of Mines study that incorporates coal mining factors, cola recovery factors, and economic factors into the definition of an economically recoverable coal resource. The relationship between these factors to the Energy Information Administration's estimate of U.S. coal resources--the "Demonstrated Reserve Base"--is discussed. The Boltsfork 7 1/2-minute quadrangle in eastern Kentucky was selected as the stud area. Results indicate that of the original 280.2 M tons of resource in the quadrangle, only 99.8 M tons (35.6%) is recoverable at a mining cost of $25 per ton or less" (p. 1).

Report issued by the U.S. Bureau of Mines over state mine inspection reports from 19 U.S. states. The information in the reports includes details of accidents, locations that specific accidents occurred, and proposed remedies for prevention of future accidents. This report includes tables.

Report issued by the U.S. Bureau of Mines discussing the annual report over the research and technology of coal during 1941. As stated in the foreword, "these investigations increase our fund of exact knowledge on the properties and composition of American coals and lead to better methods in mining, preparing, storing, and utilizing coal" (p. 4). This report includes tables, illustrations, photographs, and a map.

Report issued by the U.S. Bureau of Mines discussing dredging methods of used by the Ohio River Sand Company. The different methods and costs used to recover gravel and sand are described. This report includes tables and illustrations.

Report issued by the U.S. Bureau of Mines discussing the mine stations and safety cars used to reach miners in distress. As stated in the report, "the purpose, equipment, personnel, and construction of its safety cars" is presented. This report includes an illustration, and a map.

Report issued by the U.S. Bureau of Mines discussing bituminous coal and lignite seams found in the United States. The thickness of seams from several U.S. states is compared, as well as the mining methods employed. This report includes maps, tables, and illustrations.