Vintage Copper Mining Methane Detector Lamp . . . . .Lamp was used by a copper miner in Michigan's upper peninsula, copper country. . . . . I know very little about this item, so I am uncertain as to whether or not this is a working lamp . . . . .Lamp measures about10 1/2" in height without the hook . . . ..T are no breaks or cracks in the glass area of the lamp . . . . .T is some light rust and soil . . . . .Manufactured by the Koehler Manufacturing Co. Marlboro, Mass. . . . ..The number 3 was painted in red in two different places on the lamp probably for indentification purposes.