LAMP, a vessel used for the combus tion of liquid inflammable bodies, for the purpose of producing artificial light. The invention of the lamp is ascribed to the Egyptians. In treating of the con struction of modern lamps, it is neces sary to take into consideration the nature of the flame. In order to insure a con stant and steady flame, it is necessary that the supply of combustible mattter be steady and uniform. It must, there fore, be either in a liquid or gaseous state, so that it may approach the flame in an uninterrupted current. The com bustible substance may either be made to approach the flame by capillary attrac tion through wi,:txs, or by mechanical pressure. The invention and introduc tion of the ARGAND LAMP (q. v.) (1789) made a revolution in illumination.
The introduction of mineral oils as il luminants caused a great variation in the construction of lamps, and a host of patents have been taken out for paraffin or kerosene lamps, some of which equal gas in illuminating power. The central
draft-lamp using a round tubular wick that is raised or lowered by a rod operat ing a spurred wheel is one of the most popular. Lamps are now extensively used for heating and cooking, a double or triple flat wick being employed. In the United States and Europe vapor lamps are employed. In these, which consume the volatile hydrocarbon obtained from the products of the distillation of bi tuminous coal, the liquid is converted into vapor before it reaches the burner, and burned without the need of a wick. Some employ mantles. They are there fore distinguished as vapor or self-gen erating gas lamps. In 1868 a lighthouse lamp for burning mineral oils was in troduced, and has been adopted in all parts of the world. These lamps have two or more concentric wicks, and yield a very powerful light. A safety lamp, used everywhere by miners, was invented in 1815.