Lamp

(lămp.) [Fr. lampe.] A contrivance in which to burn any light-giving material, and so make use of its illuminating power. The invention of lamps has been attributed to the Egyptians, but it is far more probable they received it from the older civilization of India. Among the most beautiful remains of antiquity which have been preserved, are a great number of Egyptian, Greek, and Roman L., formed of clay, metal, terra-cotta, and bronze. The form of these is for the most part oval: flat on the top, with figures in relief. At first, the Greek lychna, and the Roman lucerne, were made only with one wick-hole (Fig. 430); but their light-giving power was succe ively increased by their being made to hold several wicks. No great improvement, Fig. 430.-ROMAN LAMP. (Museum of the Louvre.) however, took place in the construction ofL. until the beginning of the present century. Taste had been shown in the designs, but the principle remained the same-a wick sucking up oil from the reservoir of the L. to supply itself during combustion. In 1803, M. Carcel, a French man, made quite a revolution in L. by applying clock-work, which acts by raising the oil up tubes in connection with the wick, so that the latter is kept constantly soaked. But the greatest improvement in oil-L. was the French Moderator, which at once displaced the Carcel ys tem. In this, as in Carcel's, the reservoir for the oil is below, but it is forced up to the required level by the action of a spiral spring, whose tension requires to be renewed, or the spring wound up, once in 12 hours. The oil-L., however, has become almost obsolete, since the rapid extension ofgas-works, and the invention of L. to burn the various kinds of naphtha, petroleums, and paraffine oils. These lamps require to be formed so as to insure perfect combustion | of the material, for which purpose the reservoir of fluid is placed much below the flame, and the wick pa es into it and sucks it up by capillary attraction. The gla chimney which surrounds the wick is always made very narrow at the bottom and top, with an enlargement round the flame. This figure insures a great in draught of air at the bottom, which keeps the combustion so perfect, that in a well-made lamp the smoke is imperceptible; in addition, there is an arrangement surrounding the wick-tube for admitting air, and bringing it into contact with the flame. These lamps give a most brilliant light; and as they not only have greater illuminating power, but are of cheap construction, and are very economical in other respects, they have come into general use.-LAMP (ELECTRIC). See ELECTRIC LIGHT. [s. 524]