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Occulting Light Clockwork

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Postby island » Thu Oct 13, 2011 10:32 pm


I found this item when looking through the following report.An inexpensive method to convert a fixed light to occulting with for example five seconds of light and one second or eclipse.

Report of The Lighthouse Board. 1893, THE OCCULTlNG Light. (See pp. 234, 235.)

Many harbor lights are of sufficient intensity to be seen as far as needed, but it is difficult to distinguish them from other lights. Effort was made to overcome this difficulty by obscuring the specified light automatically, from time to time, by an opaque screen. This was done by inclosing the chimney of the lamp which gives the light with a brass cylinder, which is raised to show the light and dropped to its resting place to hide it. The cylinder is raised and lowered by clockwork. The clocks are so geared that the eclipse and flashes may be as frequent as is desired, and the length of each can be regulated at will within narrow limits.

In the occulting light the wheel revolved once in 20 or 30 seconds, according to the positions of the fans, and each revolution caused ten flashes and ten eclipses. The machine cost about $1,000, with all its accessories.

Seven of these new occulting lights are now in use. One is shown at Tawas light-station, Michigan; one at Point Hueneme light-station, California; and others are shown at Ship John Shoal, Cross Ledge, Brandywine Shoal, Fourteen-Foot Bank, and Delaware Breakwater Front Range light-stations in Delaware Bay. Occulting lights are being constructed for certain front range lights in Delaware River.
island
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