A flat-wick lamp is a simple type of kerosene lamp, which burns kerosene drawn up through a wick by capillary action. If this type of lamp is broken, it can easily start a fire. A flat-wick lamp has a fuel tank (fount), with the lamp burner attached. Attached to the fuel tank, four prongs hold the glass chimney, which acts to prevent the flame from being blown out and enhances a thermally induced draft. The glass chimney needs a "throat", or slight constriction, to create the proper draft for complete combustion of the fuel; the draft carries more air (oxygen) past the flame, helping to produce a smokeless light, which is brighter than an open flame would produce.