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| Photo by Eakin Howard |
One year before our lighthouse was built, a Frenchman, Augustin Fresnel, invented an ingenious system of glass prisms and bull's eyes that concentrated and magnified light. The Lighthouse Board began the installation of the much more efficient Fresnel Lenses late in 1852
In 1854, Ocracoke's revolving light and old reflecting system was replaced by a fixed white light surrounded by a fourth order Fresnel lens.
A Franklin lamp replaced the old valve lamp in 1899 (see http://uslhs.org/sites/default/files/assets/resources/Lighthouse%20Related%20Patent%20Models.pdf for descriptions and photos of various lighthouse lamps, regulators, and burners). A new Fresnel lens was installed soon thereafter. The bronze base of the Fresnel lens, which is still in use today, is embossed with this information about the manufacturer: F. BARBIER & Cie. Constructeurs PARIS - 1890.
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| Photo by Eakin Howard |
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| Photo by Eakin Howard |
This month's Ocracoke Newsletter is about the almost forgotten 1890 "Oyster Wars" that pitted islanders against outside business interests. You can read the article here: http://www.villagecraftsmen.com/news012115.htm.
If you are interested in Fresnel lenses, check out the book "A Short Bright Flash: Augustin Fresnel and the Birth of the Modern Lighthouse" by Theresa Levitt. I first saw it at a bookstore somewhere on the Outer Banks this past summer, but finances didn't allow me to buy all the books I saw and wanted...so I got a copy of it as a Christmas gift. I'm about half way through reading it now...it's quite interesting. It speaks of reflecting apparatus in use at the time, such as you note was originally in the Ocracoke light. Fresnel didn't just invent the lenses, he helped prove the wave theory of light. It was quite a challenge to create the first lens, between getting the funds, and finding someone who would and was capable of producing the near-perfect prisms that were required. And after all that, he died of TB at the age of 39...
ReplyDeleteThank you for the information. This book is exactly what I enjoy reading. I will order it from Leslie at Books to be Red.
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