Deck prism—used to help light lower decks of USS Constitution with light from higher deck, 18th century

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Deck prism—used to help light lower decks of USS Constitution with light from higher deck, 18th century
Had a moment of brilliance over some of these recent storms to hit my area and knock out power
I grabbed my ship deck-prism and put it on top of a small flashlight/ phone flashlight and it illuminated like a lantern
The same way it was designed to for light from the sun into the area below deck on ships, it turned a point source light into a room illuminating light
I've had it as a paperweight on my desk and just reached for it wondering if it would work and it totally did
A nautical history mystery where 19th-century whaling meets Dinotopia. Featuring cameos by the HMS Erebus and the HMS Terror!...
A nautical history mystery where 19th-century whaling meets Dinotopia. Featuring cameos by the HMS Erebus and the HMS Terror!
(the original post)
With thanks to @haverkampink, @placesandpalaces, and @focsle!
The deck prism is a beautiful object created before the times of electricity, when the only way to safely illuminate the interior of a wooden ship was to refract light through a prism in the deck.
Deck glass prism of USS Constitution, mid 19th century
These lie flush on the deck so that the glass prism refracts the natural light and diffuses it onto the deck below to provide illumination.
got an exciting episode coming up for you this week
Deck Prism, 19th century
A deck prism is a prism inserted into a ship's deck to provide light below. For centuries, sailing ships used deck prisms to provide a safe source of natural sunlight to illuminate areas below decks. Before electricity, light below a vessel's deck was provided by candles, oil, and kerosene lamps—all dangerous aboard a wooden ship. The deck prism laid flush into the deck, and the glass prism refracted and dispersed natural light into the space below from a small deck opening without weakening the planks or becoming a fire hazard.
The names "deck light," "dead light," or "deadlight" are sometimes used, though the latter is uncommon as a reference to prisms, as more often refers to non-opening plain-glass panels. Deadlights were commonplace for lighting underground vaults in the 19th century; they were also called "pavement lights" (UK) or "vault lights" (US).