Arc lamp

The concept was improved upon by a number of people including William Staite and Charles F. Brush. There were attempts to produce the lamps commercially after 1850 but the lack of a constant electricity supply thwarted efforts. It was not until the 1870s that lamps such as the Yablochkov candle were more commonly seen. The harsh and brilliant light was found most suitable for public areas, being around 200 times more powerful than contemporary filament lamps. There were two major advances in the 1880s when the arcs were enclosed in a small tube to slow the carbon consumption (increasing the life span to around 100 hours) and with the introduction of flame arc lamps, where the carbon rods had added salts (usually magnesium, strontium, barium or calcium fluorides) to increase light output and produce different colours.

The arc lamps were soon superseded by the more efficient and longer-lasting filament lamps in most roles, remaining in only certain niche markets such as cinema projection and search lights.

Arc lamp

See also