Lighthouse at Jupiter Inlet, Florida which has been in service since 1860.
A Fresnel lens (pronounced [freɪ'nel]) is a type of lens invented by French physicist Augustin-Jean Fresnel. Originally developed for lighthouses, the design enables the construction of lenses of large aperture and short focal length without the weight and volume of material which would be required in conventional lens design. Compared to earlier lenses, the Fresnel lens is much thinner, thus passing more light and allowing lighthouses to be visible over much longer distances. (quote from Wikipedia.org)Note the two dark panels in the pictures above. The light remains fixed and the lens' rotate around the light. When the dark panels are in front of the light, it appears to flash "off" until the next open panel is in front of the light. The timing of the rotating combination of open and covered lens' create a signature that sailors can recognize.
Motorized gear mechanism that turns the lens'.
137 narrow stairs that lead from the base to the top.
Small building that contained oil for the lanterns used for the light until it was converted to use electricity (around 1930 I think).
1 comment:
Looks great ❤️
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