A lighthouse is a tower, building, or framework designed to emit light from a system of lamps and lenses or, in older times, from a fire and used as an aid to navigation and to pilots at sea.
Lighthouses are used to mark dangerous coastlines, hazardous shoals and reefs, and safe entries to harbors and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and re...
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A lighthouse is a tower, building, or framework designed to emit light from a system of lamps and lenses or, in older times, from a fire and used as an aid to navigation and to pilots at sea.
Lighthouses are used to mark dangerous coastlines, hazardous shoals and reefs, and safe entries to harbors and can also assist in aerial navigation. Once widely used, the number of operational lighthouses has declined due to the expense of maintenance and replacement by modern electronic navigational aids.
In a lighthouse, the source of light is called the "lamp" (whether electric or fueled by oil) and the concentration of the light is by the "lens" or "optic". Originally lit by open fires and later candles, the Argand hollow wick lamp and parabolic reflector was developed around 1781 in Europe. In the US, whale oil was used with solid wicks as the source of light, until the Argand parabolic reflector system was introduced around 1810 by Winslow Lewis. Colza oil replaced whale oil in the early...
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