Report discussing earthquake activity in the United States during 1931. The report is broken down by regions and has sections for specific earthquakes.

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."

From Prefactory Statement: "In this bulletin are presented the results obtained in the first two phases of the work outlined above. The bulletin is in two parts. The first part describes the methods of mining and milling used, suggests a standard method of sampling finished graphite, and describes a rapid and convenient method of analysis developed at the Pittsburgh station of the Bureau of Mines, to which has been assigned the analytical and microscopic work. The second part describes experiments on the concentration and milling of graphite, which were made at the Salt Lake City, Utah, station."