Biennial Report, Τόμοι 1-2

accident air-way Albia Angus appointed bituminous coal Bituminous shales black-damp Blue sand shales Boone county Boonesboro cage carbonic acid cause charge Coal and Mining Coal Company coal measures coal mines comply condition Coroner court creek cubic feet Dark death district dollars Drift deposit duties engine entry escape shaft examination feet per minute five furnace furnish Governor Gray clay shales hoisting shaft hole hundred feet Impure inches inspection inspector of mines jurors Kalo Keokuk county Kirkville labor Light limestone located Lucas county machinery Mahaska county map or plan MCELHANY miles miners mining boss Mining Company mining law Moines river oaths do say opening Oskaloosa Ottumwa owner or agent persons employed Polk county pressure proper railroad rock roof safety safety-lamp sandstone shaft or slope side superintendent therein thereof thickness thousand tion underground ventilation volume of air Wapello county William