 It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century.It continued in use in more specialized applications where a high intensity point light source was needed,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 searchlights and movie projectors until after World War II.The carbon arc lamp is now obsolete for most of these purposes, but it is still used as a source of high intensity ultraviolet light.