Monday, September 18, 2017

Winslow Lewis

When the Ocracoke Lighthouse was built, in 1823, it was fitted with fifteen Argand lamps and an equal number of parabolic reflectors and glass magnifying lenses. This arrangement was the creation of Winslow Lewis, a New England sea captain, engineer, and inventor.

19th Century Drawing of a Lewis Lamp



















The drawing above shows the Argand Lamp in the center. The Argand Lamp (invented by Swiss-born physicist Aime Argand in 1782) used a circular wick placed between two thin concentric brass tubes, and enclosed within a glass chimney. To the right is the thin, silver-plated copper reflector. On the left is the lens. A reservoir to hold the oil is situated behind the reflector.

Unfortunately, Lewis' parabolic reflectors tended to warp, resulting in a spherical shape. And the lenses were quickly covered with soot, greatly reducing the luminosity. 

In 1849 ten lamps and twenty-one reflectors replaced the original apparatus. In was not until 1854 that a much more efficient  fourth order Fresnel Lamp replaced the original reflecting-illuminating lamps.

This month's Ocracoke Newsletter is a brief history of Howard's Pub. You can read it here: https://www.villagecraftsmen.com/news082117.htm.    

3 comments:

  1. Anonymous11:26 AM

    did the lighthouse ever burn kerosene to illuminate the light. i suppose the early oil producers had the lightkeepers over a barrel when charging for oil to burn how some things don't change unless america reduces it's dependence on oil.

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    1. Sperm oil was the oil used in America's first lighthouses. When the price became burdensome, the Lighthouse board considered colza oil, lard oil and kerosene. Sufficient quantities of kerosene to light our nation' lighthouses were not available until after 1859 (think Titusville, PA). Even then, the quality of kerosene was poor. By 1867 virtually all lighthouses were burning lard oil. After 1870, the board gradually shifted to the use of cheaper and now more refined kerosene. Eventually, electricity supplanted kerosene.

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    2. Anonymous7:49 AM

      electricity supplanted kerosene hmmmm how is the electricity generated?? Wait, let me guess --- Gas-oline?? is used to generate the light... which is kind of like kerosene.(refined from oil) And there is not enough wind as a clean source of power but someone should harness the power of the WAVE

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