Report of Investigations

accidents amount anthracite mines average bituminous black blasting blasting Bureau of Mines capacity causes cent chute classes close coal mines companies compared concentrations containing copper crude oil death Department of Commerce detonators distillate drilling dust electric equipment face Falls fatality February feet fields figures fire flotation flow fractions fuse gas-oil ratio gasoline give given gravity high explosives hole increase indicated industry iron January July kegs lead light Lignite machine manufacturing March material metal method mica Michigan million mills mineral months obtained operated oxidized percentage period permissible petroleum placed pounds powder present pressure produced quantity Reports Reports of Investigations represented roof samples sand Serial shown shows sold solution Specific sulphide sulphur Table tank temperature Texas tons tons of coal tubing United Virginia viscosity wire