Museum hosts talk on Fresnel lens

How do you move a first-order Fresnel lens, complete with 1,008 glass prisms? Very carefully, is the quick answer. Lampist James Woodward will tackle this topic, as well as the history of Fresnel lenses and the importance of the Island’s 1854 Fresnel lens, originally from the Gay Head Lighthouse, in a free talk given Thursday, Nov. 1, at 6 pm at the Morgan Learning Center, 110 Main St., in Vineyard Haven.

Woodward is part of a team of several individuals currently in charge of conserving, moving, and reassembling the historic Fresnel lens in the museum’s new home in Vineyard Haven. The group, which consists of experts from all over the country, was on the Island first in May to disassemble the lens in its previous home on the museum’s Edgartown campus. Since then, various pieces of the base have been restored off-Island, and the 1,008 glass prisms have remained carefully packed in crates, safe from all the construction at the former Marine Hospital. Reassembly of the lens is set to begin on Oct. 27. According to a press release, the process will take up to two weeks.

As part of the reassembly, Woodward will give a talk on the process he has led to restore the lens, how Fresnel lenses came to be, and their importance throughout history. Photos of the conservation effort thus far will be included. Due to the ongoing construction at the new museum, the public is not allowed access to the site to see the lens come back together. A time-lapse webcam has been set up inside the new Fresnel Lens Pavilion, and a video is also being created by the museum’s oral history team of the disassembly and reassembly.

In 2016, the M.V. Museum received a grant from the Institute of Museum and Library Services to conserve and move the historic Fresnel lens. The lens required conservation treatment to alleviate corrosion, stabilize cracked panels, and replace damaged or missing elements. The entire structure also needed a thorough cleaning. Once moved to the new pavilion at the museum, its condition will be more easily monitored, and its routine maintenance will be achievable in a way that is not possible at the campus in Edgartown.

Ordered by the U.S. government and built by Henri LePaute of Paris, the lens originally served as a beacon to seamen beginning in 1856. According to the release, the Fresnel’s hundreds of prisms, arranged in a beehive shape, refracted and reflected light from an oil-burning lamp, directing it into a single beam that could be seen 20 miles away. It was a scientific wonder of its day, the invention of Augustin Fresnel (1788-1827). The Fresnel design became the standard lens in many lighthouses around the world, and smaller, fourth-order lenses were installed in four other Martha’s Vineyard lighthouses. After almost a century in the Gay Head Lighthouse, the lens was replaced with an electric beacon and moved to the museum campus in Edgartown. The lens is the largest made, and is one of only 39 first-order Fresnels remaining in the U.S. With its clockwork, pedestal, chariot assembly, pulley, and weights, it is also one of the most complete.