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January 15th 1798

A forum to discuss lighthouses in the New England Region of the US
(Maine, New Hampshire, Rhode Island, Massachusetts, Connecticut, Vermont)

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Postby Grover1 » Thu Jan 15, 2009 8:20 pm


From Cape Cod Today

http://www.capecodtoday.com/blogs/index ... i?blog=161

An 1856 Illustration ...
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Believe those who search for the truth ...
Doubt those who find it ...
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Grover1
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Postby island » Fri Jan 16, 2009 12:09 am


If you note in the url for this article it says America's first lighthouse but the author amended the article to read, one of America's first lighthouses.

Highland Light was a first, the first to have a flashing light, or more accurately stated, the first attempt. Soon after the light became operational an eclipser (revolving opaque screen) was installed to cause the light to appear to flash. But the eclipsor was far to slow taking 80 seconds per Jeremy D, 8 minutes per E.R.Snow, to complete one revolution around the 15 lamps, 7 over 8, in the tower. Instead of a flash, when viewed from the ocean the light would become very gradually dimmer until no light was visible for 30 seconds per Jeremy D. and then it would very slowly become brighter. ( I think Snow's 8 minutes is a bit of a stretch.)

Not only was the eclipser too slow but with the lamps set apart and therefore no concentrated light it would be not possible to create a distinct flash. (This is also the same problem with the new led lamps that prevent them from use in sectored lights. The led's would not produce a distinct visual boundary between sectors.)

Another interesting fact is the tower height was reduce about 15 feet to overcome a problem from high level mists obscuring the the light. The original focal plane was at first 160 feet. It is questionable if this improved the light.
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