Safety Lamp

a miner's lamp. As is well known, the passages in mines, especially coal mines, fill not infrequently with an explosive gas called fire damp. It is a compound of hydrogen and carbon, mixed with atmospheric air. In the earlier days of coal mining, fire-damp explosions were so frequent and so disastrous to human life that Sir Humphry Davy, an English chemist, gave the subject serious attention and invented his so-called safety lamp. The flame of the lamp is surrounded by a wire gauze having about 625 meshes to the square inch. This lamp may be lighted and carried into the dangerous fire damp without an explosion. The gases pass through the meshes of the gauze and burn with a feeble blue flame within, but not in such a way as to obstruct the light of the lamp. The flame of the lamp and of the burning gas within cannot pass out through the meshes of the gauze without being cooled to such an extent that there is no danger of igniting the gas in the mine. The safety lamp is constructed in such a way that it may be attached to the miner's hat band and worn on the forehead as he goes about his work. See Damps; Davy; Sir Humphry