Report issued by the U.S. Bureau of Mines on the air quality in metal-mines after using wet drills. Dust samples are collected and compared to samples collected from similar metal-mines in South Africa and Australia. This report includes tables.
Report issued by the Bureau of Mines over production of oil-shale facilities in South Africa. The deposits of oil-shales, and torbanites are described. The operations at the production facilities are also presented. This report includes tables, maps, illustrations, and photographs.