The Encyclopedia Americana: The International Reference Work, Volume 7Americana Corporation, 1955 - Encyclopedias and dictionaries |
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Page 151
... mining . Some of the more impor- tant factors that must be taken into consideration in choosing the method to be used in mining a coal seam are available tonnage , inclination and thickness of the seam , character of the coal , gas and ...
... mining . Some of the more impor- tant factors that must be taken into consideration in choosing the method to be used in mining a coal seam are available tonnage , inclination and thickness of the seam , character of the coal , gas and ...
Page 153
... mining , the output from underground mines using power drills in 1945 ( 384,234,131 tons ) representing about 82.2 per cent of the United States underground bituminous output for that year . Loading . As in cutting coal , hand labor in ...
... mining , the output from underground mines using power drills in 1945 ( 384,234,131 tons ) representing about 82.2 per cent of the United States underground bituminous output for that year . Loading . As in cutting coal , hand labor in ...
Page 654
... mined at relatively low costs per ton as compared with the costs and daily tonnages realized in mining copper ores from deposits of the vein and replacement types . As a comparison , a single large vein mine might produce an average of ...
... mined at relatively low costs per ton as compared with the costs and daily tonnages realized in mining copper ores from deposits of the vein and replacement types . As a comparison , a single large vein mine might produce an average of ...
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19th century American army Battle became bituminous coal Bogotá British called cent century chief Church Clark clay cleft palate Cleveland climate Club coal coast cobalt cocaine Cochinchina coeducational coelacanths coffee coins coke College colloidal Colombia colonies color Colorado Columbia Columbus comet comic commerce Confederate Congress countries County seat East elected England English established Europe federal feet forces France French German important Indian industry Island Italy John June known land later latitudes London manufacturing ment miles mining North North America ocean Ohio operation organized ovens Pacific Paris period plants polar easterlies port president Railroad River Roman ships South Southern species square miles temperature theater tion town trade transportation Union United University vessels William women World War II yellow York