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 It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century.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
Moderator lamp Moderator lamp The moderator lamp is a type of 19th century oil lamp. It displaced the more complex Carcel lamp which used a clockwork pump. Its mechanism was simpler and required less maintenance or repair. The moderator lamp was invented in 1837 by Charles-Louis-Félix Franchot (1809-1881) . Like the Carcel lamp the oil reservoir was below the burner and it allowed 360 degree illumination. Earlier oil lamps such as the Argand had a reservoir above the burner which made them top heavy and obscured some of the light. The reliability of the mechanism led to them being adopted in lighthouses.