When the light is attended, there will frequently be a group of buildings around the tower for the fog signal and radiobeacon equipment and station personnel. Such a group of buildings constitutes a light station. The flashing lights of lighthouses, bouys, and other aids to navigation are produced in several ways. In some large lights the flashes are produced by rotating lenses. Some electric lights are flashed by timers which break the current flow.
All large lighthouses use electricity.
Incandescent lamps produce as much as 5,000,000 candlepower where such brilliance is needed. Lenses of highly polished glass prisms are assembled in many types to produce the characteristics needed. The above text is from the Sixth Edition of The Coast Guardsman's Manual . Argand Lamp - A hollow wick oil lamp. Astragal - Metal bars dividing the lantern room glass into sections.