...diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

..."diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...diligent investigation of the methods of mining, especially in relation to the safety of miners, and the appliances best adapted to prevent accidents,...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...diligent investigation of the methods of mining, especially in relation to the safety of miners, and th* appliances best adapted to prevent accidents, the...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...

...investigation of the methods and mining, especially in relation to the safety of miners" . . . and "the possible improvement of conditions under which mining operations are carried on." 1 EncompaHHlng health activities within the Department of Health. Education and Welfare. Research conducted...

...investigations of the methods of mining, especially in relation to the safety of miners and the appliances beet adapted to prevent accidents, the possible improvement...under which mining operations are carried on, the treatment of ores and other mineral substances, the use of explosives and electricity, the prevention...