Palmer, Earl2011-08-152011-08-152005-05-17ep136.jpeghttp://hdl.handle.net/10919/10830There's always the danger of methane gas explosions, slate falls, and presence of "black damp" in the mines.8 inches x 10 inchesimage/jpegen-USIn CopyrightCoal -- Appalachian RegionCoal miningSignsMinesImageVirginia Tech. Special Collections Department