An M.S.A. Automatic Firedamp Detector.
M.S.A. Automatic Firedamp Detector, Type AFD-1. Size 11″ x 4″ x 3″ inches. It has a steel hanging hook and a mesh detecting sensor at the top with a Red warning light at the bottom.
Firedamp is a flammable gas including Methane that is found in all coalmines, the word damp is a collective name given to all gases, Stinkdamp – (Hydrogen Sulphide): Blackdamp – (Carbon Dioxide): Also Afterdamp – (Carbon Monoxide):