Mines and Minerals, Volume 30

acid afterdamp amount bismuth bituminous coal boiler bottom brattice Cananea carbon carbon dioxide carbon monoxide Carbonado cars cent chalcopyrite clay coal mines Coalburg coke colliery contains conveyer copper cost Creek crushed cubic dacite deposits diameter district drift drill dust electric engine entry explosion feet fire firedamp furnace gases gold grade haulage heat hoisting holes horsepower Idaho Springs inches inspector iron Kanawha lamp located locomotive machine metal methane method mill Mines and Minerals motor operation pillars pipe Pittsburg plant plumb-bob porphyry pounds practically pressure production pump pyrite quantity railroad revolutions per minute River rock roof sample seam shaft shot shown in Fig shows side solution steam steel stope sulphur surface temperature tests thickness timber tion tons tube vanadium veins ventilation vertical West West Virginia wire Written for Mines zinc