Arc lamp Arc lamp An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, was the first practical electric light. It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century. It continued in use in more specialized applications where a high intensity point light source was needed, such as
Safety lamp was surrounded by gauze so that in the event of a glass breakage the Geordie became a Davy. If the current of air forced in through the tubes (later holes and gallery) by the lamp's situation was too strong, the flame grew, and the lamp could get red-hot. The lamp becomes unsafe in a current of from 8 to 12 feet per second, about twice the limit of the Davy's safe operating conditions. However, this variation in the flame was not entirely bad. The intensity of the flame, air currents being equal, gives an indication of firedamp levels, so it