ABSTRACT
Electric illumination spread throughout the late 19th and 20th centuries, as carbon, tungsten and subsequently ductile tungsten filament bulbs were successively replaced, and fluorescent and neon innovations were introduced. Although 19th-century acetylene gas lamps, electric carbon arc lamps and high-power electric filament lamps increased the efficacy of lighthouses and so maritime safety, it was the invention of the 18th-century Argand oil lamp that enabled the development of modern lighthouse optical components. For even brighter lights, including in some lighthouses, several concentric circular wicks were used. A candle is also an oil lamp, the wick stands in a pool of molten wax. A larger wick consumes more oil and gives a larger flame, but not much more light. The lens is one of the most important technologies in history, and the Fresnel lens has enabled a number of important variations on the basic lens design–the lighthouse being the most famous of them all.
