Helmet Carbide Lamp - Butterfly

Early 20th century carbide lamp that hooks onto the front of a helmet used by miners. Manufactured by Butterfly.

Carbide lamps, also known as acetylene gas lamps, are simple lamps that produce and burn acetylene (C2H2) which is created by the reaction of calcium carbide (CaC2) with water. The conventional format of producing acetylene in a lamp is by putting the calcium carbide in the lower chamber (the generator). The upper reservoir is then filled with water. A threaded valve or other mechanism is used to control the rate at which the water is allowed to drip onto the chamber containing the calcium carbide. By controlling the rate of water flow, the production of acetylene gas is controlled. This, in turn, controls the flow rate of the gas and the size of the flame at the burner, (and thus the amount of light it produces).