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accidents amount annual anthracite anthraxylon appearance attritus Average basis bituminous BULLETIN Bureau of Mines CALENDAR carbonaceous cars causes cell cent coal beds coal fields COAL MINES columns compared Compiled components contain County district Electricity shock employed examined explosion Falls of roof fatality rate feet field Figures fire follow foot gas and dust Group horizontal section humic matter Illinois increased injuries inspection inspector layer less lignite locomotives matter method Michigan miles Mining machines motives nature North Number killed operators original particles Pennsylvania percentage period photograph Pittsburgh plants ployed production records reports represent resinous rock sample SECTION OF COAL seen shock or burns short showing shown in Plate similar spore spore-exines strips structure suffocated surface Survey TABLE thick thin cross section THIN VERTICAL SECTION tissue tons Total underground United varying Virginia wall West woody workers
Σελίδα ii - The Bureau of Mines, in carrying out one of the provisions of its organic act — to disseminate information concerning investigations made — prints a limited free edition of each of its publications. When this edition is exhausted, copies may be obtained at cost price only through the Superintendent of Documents, Government Printing Office, Washington, DC The Superintendent of Documents is not an official of the Bureau of Mines.
Σελίδα 49 - ... or more shall be collected. The gross sample should contain the same proportion of lump coal, fine coal, and impurities as is contained in the coal sampled. When coal is extremely lumpy, it is best to break a proportional amount of the lumps before taking the various increments of a sample.
Σελίδα 22 - V) by depositing each shovelful of coal on top of the preceding one, and then formed into a long pile in the following manner : The sampler shall take a shovelful of coal from the conical pile and spread it out in a straight line (Figs.
Σελίδα 49 - MOISTURE. 1. The coal shall be sampled when it is being loaded into or unloaded from railroad cars, ships, barges, or wagons, or when discharged from supply bins, or from industrial railway cars, or grab buckets, or from any coal-conveying equipment, as the case may be. If the coal is crushed as received, samples usually can be taken advantageously after the coal has passed through the crusher. Samples collected from the surface of coal in piles or bins, or in cars, ships or barges are generally...
Σελίδα 49 - ... increments. For slack or small sizes of anthracite, increments as small as 5 to 10 pounds may be taken, but for run-of-mine or lump coal, increments should be at least 10 to 30 pounds.
Σελίδα 69 - Mining and treatment of feldspar and kaolin in the southern Appalachian region, by AS Watts. 1913. 170 pp., 16 pis., 12 figs. BULLETIN 56.
Σελίδα 69 - BULLETIN 17. A primer on explosives for coal miners, by CE Munroe and Clarence Hall. 61 pp., 10 pis., 12 figs. Reprint of United States Geological Survey Bulletin 423. BULLETIN 20. The explosibility of coal dust, by GS Rice, with chapters by JCW Frazer, Axel Larsen, Frank Haas, and Carl Scholz. 204 pp., 14 pis., 28 figs.
Σελίδα 99 - BULLETIN 116. Methods of sampling delivered coal, and specifications for the purchase of coal for the Government, by GS Pope.
Σελίδα 49 - ... analysis is in error, another analysis can easily be made of the original sample. Gross samples of the quantities designated herein must be taken whether the coal to be sampled consists of a few tons or several hundred tons, because of the following cardinal principle in sampling coal that must be recognized and understood; that is, the effect of the chance inclusion or exclusion of too many or too few pieces of slate or other Impurities in what, or from what, would otherwise have been a representative...