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}} Alcatraz Island Lighthouse is a lighthouse – the first one built on the U.S. West Coast – located on Alcatraz Island in California's San Francisco Bay.〔 It the southern end of the island near the entrance to the prison.〔(【引用サイトリンク】title=Alcatraz Island, CA )〕 The first light house on the island was completed in 1854, and served the bay during its time as a Citadel and military prison. It was replaced by a taller above mean sea level) concrete tower built in 1909 to the south of the original one which was demolished after it was damaged due to earthquake in 1906. The automation of the lighthouse with a modern beacon took place in 1963, the year Alcatraz closed as the Alcatraz Federal Penitentiary. It is the oldest light station on the island with a modern beacon and is part of the museum on the island.〔〔 Although when viewed from afar it easily looks the tallest structure on Alcatraz, it is actually shorter than the Alcatraz Water Tower, but as it lies on higher ground it looks much taller. ==History== Even though the Native Indians of the San Francisco area are stated to be the original settlers on the island (they collected eggs from the large flock of birds that regularly gathered there), Alcatraz got its name in 1775 only when Juan de Ayala, a Spaniard was engaged to survey the harbor and the San Francisco Bay. Since he observed pelicans in large numbers on the island he named the island as "Isla de los Alcatraces” meaning the “Island of Pelicans”. The island is separated from the main land by more than . The gold rush and the inherent risk of the choppy waters of the west coast prompted the urgent need for establishing lighthouses. Congress recognized the need and passed suitable acts in the years 1851 and 1852 to build seven lighthouses on the West Coast to guide navigation.〔 The Baltimore firm of Gibbons and Kelly was awarded the contract to build seven lighthouses in California, at Alcatraz Island, Fort Point, Point Piños, Point Loma, Farallon Island, and Humboldt Bay, and one at Cape Disappointment in Washington State. Equipment were shipped on Oriole, reached San Francisco on January 29, 1853. The Alcatraz Lighthouse was the first to be completed in July 1853, making it the oldest major navigational light on the West Coast. However, the foundation for building the light house had begun much before the equipment reached San Francisco.〔 In the original order placed for supply of the equipment Argand lamps and parabolic reflectors had been specified as the Fresnel lens, created by Augustin Fresnel of France in 1822 was considered very costly at that time. However, the Lighthouse Board which replaced the Fifth Auditor of the Treasury's control, decided to install Fresnel lenses in all lighthouses considering its established better performance, even though the cost was high. The Baltimore firm was informed of this change before the equipment was shipped.〔 The shipping involved a long sea voyage of from the East Coast going round the cape of South America. It was lit on June 1, 1854 from a fixed, third-order Fresnel lens. In 1902, it was transferred to the Cape St. Elias Lighthouse in Alaska and replaced by a revolving fourth-order Fresnel lens, producing a white flash every five seconds.〔 In 1909-12, the present cell house of Alcatraz was built. Since the new structure would interfere with the operation of the lighthouse, a taller , concrete tower was built south of the original lighthouse. The original lighthouse had been damaged during the great San Francisco earthquake of 1906 and was eventually torn down. In 1963, the Alcatraz Lighthouse was automated by the United States Coast Guard. In 1970 a fire destroyed the warden's house, the keepers' quarters and other buildings on the island. The only remaining building is the tall cement tower equipped with a modern beacon. The lighthouse has been a museum since 2000 and can be visited.〔 In over 50 years, the lighthouse has not been seriously damaged despite many prison escapes, the Battle of Alcatraz and fires.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alcatraz Island Light」の詳細全文を読む スポンサード リンク
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