Photo courtesy of Jean Ruland.
To see an Incandescent Oil Vapor (IOV) Lamp, visit
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Lens and Lamp Research
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This rare and unusual photograph shows the interior
of the Shinnecock Bay lighthouse's Fresnel lens as it appeared in 1918. In the photo, you
can see the incandescent oil vapor lamp, the reflector behind it, and the first order lens
within which the lamp and reflector resided. The
light's characteristic was a Group Flashing White every 7.5 seconds. More specifically,
the mariner would see the following repeating sequence:
.3 second white flash
1.6 second eclipse
.3 second flash
1.6 second eclipse
.3 second flash
3.4 second eclipse
This lens and lamp combination replaced the fixed
white light that had been installed when the tower was built in 1857. |
