Report issued by the U.S. Bureau of Mines on the magnetic base stations located in Minnesota, Michigan, and Wisconsin. The report evaluates the usefulness of the stations for calibration of certain instruments. This report contains tables, graphs, maps, and illustrations.

From Introduction and Summary: "Reports from operating companies showed that 25,715 men worked at coke ovens in 1951, about 6 percent more than were employed in 1950 and, except in 1943, the largest work force since 1930, when 28,139 men were employed. The work time for all employees was 70,190,493 man-hours. The returns indicated an average of 344 work days per man as compared with 341 days in the previous year. Accidents at the ovens resulted in the death of 10 and injury to 768 workers, both of these figures representing fewer injuries than in 1950."

Report issued by the Bureau of Mines over studies conducted on the copper-nickel deposits of Lake County, Minnesota. As stated in the introduction, "this report describes the procedures and results of the drilling program as well as the metallurgical work and laboratory studies" (p. 1). This report includes tables, maps, and illustrations.

Report regarding ion chamber measurements made of the external environmental radiation in various location in the United States during the summer of 1957.

From abstract: Results of a reconnaissance geochemical survey of the Eau Claire Quadrangle, Wisconsin; Minnesota are reported. Field and laboratory data are presented for 565 groundwater samples, 680 stream sediment samples, and 667 stream water samples. Statistical and areal distributions of uranium and other possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed.