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MIKE SPRINGER/Staff photo
Workers put the finishing touches on the preservation and reassembly of a 155-year-old Fresnel lens Monday at the Cape Ann Museum in Gloucester. The lens, which was housed in the south lighthouse tower on Thatcher Island from 1861 to 1980, is on permanent loan from the U.S. Coast Guard, and will be on display when the museum reopens on August 19.

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