The carbide lamp

Another foray into the ringing chamber village museum, actually reserved for the rubbish and collectables that the ringing master's wife, I expect, no longer wants cluttering up the home. So here are some more old bottles and also a carbide lamp. I was not quite sure how these worked but I do know that many years ago there were two or three places in the village where you could get them filled up.

Carbide lamps, or acetylene gas lamps, are simple lamps that produce and burn acetylene (C2H2) which is created by the reaction of calcium carbide (CaC2) with water. Acetylene gas lamps were used to illuminate buildings, as lighthouse beacons, and as headlights on motor-cars and bicycles. Portable carbide lamps, worn on the hat or carried by hand, were widely used in mining in the early twentieth century. They are still employed by cavers, hunters, and cataphiles.

The conventional process of producing acetylene in a lamp involves 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 into 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). This type of lamp generally has a reflector behind the flame to help project the light forward. An acetylene gas powered lamp produces a surprisingly bright, broad light. Many cavers prefer this type of unfocused light as it improves peripheral vision in the complete dark. The reaction of carbide with water produces a fair amount of heat independent of the flame. In cold caves, carbide lamp users can use this heat to help stave off hypothermia. When all of the carbide in a lamp has been reacted, the carbide chamber contains a wet paste of slaked lime (calcium hydroxide). This is emptied into a waste bag and the chamber can be refilled.
Small carbide lamps called "carbide candles" are used for blackening rifle sights to reduce glare. These "candles" are used due to the sooty flame produced by acetylene.