Miners' safety lamps. Historical artwork of two designs of Sir Humphry Davy's miners' safety lamps. They were invented in 1815 to prevent coal mining accidents, caused by explosions of methane- air mixtures ignited by the flames of miners' candles. The design incorporates an oil burner enclosed in a copper gauze. The heat of the flame was effectively contained by conduction through the wires of the gauze, ensuring that the temperature of the gauze never rose to the ignition point of the methane-air mixtures found in coal mines.