Posted by Adam Quinan on March 07, 2012 at 06:30:54 user Adam.
In Reply to: Re: What should we assume? posted by Jock on March 07, 2012 at 04:05:33:
In pre-battery/solar panel days buoys did not usually have lights. but they did have sound signals usually a weighted pendulum that hit against the cage of a buoy to produce a bell like clang when moved by the waves.
Flashing and aocculting lights were produced by the same method, a rotating shade placed between a fixed light and the observer. A flashing light has the dark period longer than the light period and the occulting light the opposite. This was created by sizing the shade appropriately, a narrow one for occulting and a wider one for the flash.
Pre-electricity, lighthouses had a clockwork mechanism to rotate the shade or light and one of the keeper's main duties was to wind the weights up to keep the mechanism going. His other duties were also to look after the lamp, usually oil, trim the wick and refill the oil reservoir as needed.