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}} The lighthouse at Fourteen Foot Shoal was named to note that the lake is only deep at this point, which is a hazard to navigation, ships and mariners. This light is located at the northern end of Lake Huron, Michigan, US, where it is necessary for boats heading to Chicago to pass through a narrow strait and still avoid shallow water. The most common path is to go south of Bois Blanc Island (Michigan). In this channel, the Poe Reef Light marks the northern end of the safe channel and the Fourteen Foot Shoal light marks the southern side of the channel. ==History== The United States Lighthouse Service intended from the time of design that this light would be automated ((possibly the first such instance) ) and operated by radio control〔(Fourteen Foot Shoal LIghthouse ) at U.S. lighthouses.com.〕 from the nearby Poe Reef Light which is away; the keeper's house was never intended to be used as a residence.〔(Edin, Colt, and Wobser, David, Fourteen Foot Shoal Light ) at Boatnerd.com.〕 In 1925 a temporary acetylene buoy was installed there and construction of the permanent light began in 1929 such that the light could begin operation in 1930.〔(Terry Pepper, Seeing the Light, Fourteen Foot Shoal Light. )〕 The original light was a fourth-order Fresnel lens.〔 * (Michigan Lighthouse Fund, Fourteen Foot Shoal Light. )〕 The focal plane is . It now has a acrylic optic Fresnel lens, and assuming it is properly installed and adjusted, has a maximum visible range of .〔(250 mm acrylic optic lens, Terry Pepper, Seeing the Light. )〕 A diaphone fog horn is attached.〔 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「Fourteen Foot Shoal Light」の詳細全文を読む スポンサード リンク
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