Pennsylvania Lighthouses on Lake Erie (Landmarks) by Ware Eugene H

Author:Ware, Eugene H. [Ware, Eugene H.]
Language: eng
Format: epub
Publisher: Arcadia Publishing Inc.
Published: 2016-06-20T04:00:00+00:00

The first turning unit using the mercury float system in a lighthouse on the French coast. From Bruckhaus and Efron Encyclopedic Dictionary, 1890.

The Ashtabula, Ohio lighthouse mercury float unit. Courtesy of Wikimedia Commons.

Fresnel lens sizes. Courtesy of Wikimedia Commons.

Unfortunately, American lighthouses were exceptionally slow in implementing the Fresnel lenses, due in large part to treasury auditor Stephen Pleasonton’s resistance to change. Annoyed by angry complaints from sailors and shippers, the federal government authorized a complete study of all the lighthouses. The study found the lighthouses, in general, to be in fairly poor condition. Pleasonton would not allow any badly needed improvements and repairs to the lighthouses, including the installation of any of the new lenses. He was discharged from his position within ninety days of the completion of the study, and the Lighthouse Board was created in 1852 to replace him. By the eve of the Civil War, all American lighthouses were using Fresnel’s technology.

The Fresnel lens design eventually was refined to include eleven orders or sizes. Each lens, while distinctly designed and slightly different, featured a standard focal length. Of these eleven orders, only six were used in the lighthouses of the Great Lakes.

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