Courtesy of U. S. Bureau of Mines
WATCHING THE CANARY
for indications of poisonous coal gas. Reserves testing the air of a mine after an explosion
Courtesy of U. S. Bureau of Mines
MEMBERS OF RESCUE TEAM
Showing apparatus worn on entering mines after explosions. This device sustains a man for two hours
The coal in the mine constantly gives off various gases, one of which, the notorious “fire-damp” (methane or marsh-gas), is responsible for many explosions. In recent years it has been discovered that coal-dust itself, when mixed with the right proportion of air, is violently explosive. Mine explosions may be minimized by requiring the use of “safety-lamps” (oil, gasoline, or electric); by providing devices to prevent sparking in electrical apparatus; and by using for blasting operations only so-called “permissible” explosives, which give a shorter and cooler flame than black powder. Coal-dust explosions can be largely prevented by wetting the walls of the mine, or by the new process of “rock-dusting,” which consists of applying dry incombustible powdered rock to all surfaces. Unfortunately, none of these precautions are employed as generally as they should be.
Press Illustrating Service