When was the first lighthouse built?

The first known lighthouse was the Pharos of Alexandria in Egypt, a 400 tower built about 280 B.C. A wood fire was kept burning on the top of the tower, which became one of the Seven Wonders of the World. Before this the light from volcanoes had acted as a guide for sailors. The first lighthouse in Britain was built by the Romans at Dover in about A.D. 43.

Lighthouse continued to be built to the plan of the Pharos until about the 12th Century. Then oil lamps and candles inside lanterns began to be substituted for fires. Shortly afterwards lighthouses suffered a decline which lasted until the great expansion of overseas trade and shipping began in the 16th Century. This led to a revival and many lighthouses were built around the coasts of Europe. The first American lighthouse was constructed on Little Brewster Island off Boston, Massachusetts in 1716.

Electricity was introduced for this purpose by Britain in 1862, when electric carbon arc lamps were installed at Dungeness lighthouse on the coast of Kent. But this source of light did not come into general use until the 1920s, when high powered filament lamps were employed. A small but powerful high pressure electric arc lamp containing a gas called xenon was installed at Dungeness in 1961, and mercury arc lamps provide the power for one of the most modern lighthouse in the United States, that on Oak Island, North Carolina. Scientists are now investigating the possibility of harnessing solar energy to operate lighthouses.