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Norah Head Light is an active lighthouse located at Norah Head, a headland on the Central Coast, New South Wales, Australia, close to Toukley. It is the last lighthouse of the James Barnet style to be built, and the last staffed lighthouse constructed in New South Wales. Officially displayed for the first time in 1903, the original vapourized kerosene burner was upgraded in 1923, electrified in 1961 and automated and demanned in 1994, after more than 90 years of being staffed. It celebrated its centenary in 2003. The concrete block tower is high, topped by a bluestone gallery. On top of the gallery is the original Chance Bros. lantern. This lantern holds the original housing of the Chance Bros. 1st order bivalve dioptric Fresnel lens. Other important structures include the chief lightkeeper's cottage and assistant keeper's duplex, and a flag house. ==History== Calls for construction of a lighthouse at Norah Head (then "Bungaree Noragh Point") were made as early as 1861 due to many wrecks occurring in the area. A notable supporter in the end of the 19th century was local landholder Edward Hargraves from Noraville. However, these efforts were fruitless for many years. The first formal recommendation to construct the lighthouse was made by the Newcastle Marine Board, just prior to its abolition, in 1897.〔See discussion of the abolition in 〕 The lighthouse was designed in a style similar to the style of James Barnet, by his successor Charles Assinder Harding, who also designed Cape Byron Light and Point Perpendicular Light. It is the last to be designed in this style. Construction commenced in 1901, undertaken by day labour. Materials were brought by boat and unloaded on a wharf constructed at Cabbage Tree Harbour for that purpose. It was officially lit on 15 November 1903, two years after Cape Byron Light. The first keepers were N. H. Williams as chief keeper, with N. Hanson and S. Kells as assistant keepers. The cost of the tower and cottages was nearly £24,000, £19,000 for the construction of the tower and £5,000 for the optical apparatus, a Chance Bros. 1st order bivalve dioptric Fresnel lens with 700 prisms The original light source was a vapourized kerosene burner and mantle generating a light intensity of 438,000 cd, visible for . The original mechanism was a grandfather clock-type mechanism with the counterweights going down a central column. The weights went down gradually as the light turned and had to be wound every half an hour. The light revolved every 10 seconds, and was floating in a mercury bath of more than to lessen the friction. The high speed of rotation made operating the light while it was active very difficult. On 13 April 1923 the light source was upgraded to a Ford-Schmidt kerosene burner with an intensity of 700,000 candlepower. It was changed to revolve every thirty seconds in 1928, to east the operation. The stables originally constructed at the complex were converted to a garage in 1960. On 28 March 1961 the light was electrified, with mains electricity as the power source, and an intensity of 1,000,000 cd. The drive was replaced with a 0.3 amp electric motor. At the same time the staff was cut from three lightkeepers to two. The light was automated and demanned in 1994.〔. Though says 1995 in the first table, the text is "It is not known when the tower was automated and demanned."〕 It was one of the last stations in Australia to demanned, after over 90 years of being staffed. The current light source is a 1000 Watt 120 Volt tungsten-halogen lamp, which flashes white every 15 seconds(Fl.W. 15s) and can be seen for .〔''List of Lights''〕 It also shows a fixed red (F.R.) and green (F.G.) lights for coastal shipping.〔 The lighthouse celebrated its centenary on 15 November 2003, and the lighthouse appeared on the cover of the Wyong Shire Council annual report for 2003. 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「Norah Head Light」の詳細全文を読む スポンサード リンク
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