A must-have for the nautical enthusiast!
This deck prism is an exact reproduction! Created by Mystic Seaport from an original on the whaler "Charles W. Morgan", each Reproduction Deck Prism is hand-poured solid glass weighing over 2 pounds.The illuminated base is sold separately (see below).
For centuries, sailing ships used Deck Prisms to provide a safe source of natural sunlight to illuminate areas below decks. Now you too can discover the charm and appeal of the past with our classically styled, nautical deck prism ( glass ). Before electricity, light below a vessel's deck was limited. Light below a vessel's deck was provided by candles, oil and kerosene lamps - all dangerous aboard a wooden ship. The deck prism was a clever solution. Laid flush into the deck, the glass prism refracted and dispersed a flood of natural light into the cabin below from a small deck opening without weakening the planks or becoming a fire hazard.
In normal usage, the prism hangs below the ceiling and disperses the light sideways; the top is flat and installed flush with the deck, becoming part of the deck. A plain flat glass would just form a single bright spot below-- not very useful general illumination-- hence the prismatic shape.
On colliers (coal ships), prisms were also used to spy on the cargo hold; light from a fire would be collected by the prism and be make visible on the deck¹ even in daylight. The names "deck light" and "dead light" or "deadlight" are sometimes used, though the latter seems to be uncommon as a reference to prisms, as more often refers to plain-glass panels.
This Reproduction Deck Prism makes a beautiful, historical, and intriguing conversation piece for any home.
** Also available is the lighted base (item # 3052450) designed to complement our Deck Prism, and has a handsome black matte finish, a U.L. approved 6-foot switched electrical cord, and a 7-watt light bulb. Prism and base sold only as separate units.
Hexagonal base 4 1/2" W tapering to a point 4 1/4" high.
Fun Facts about Prisms: The earliest deck prisms with provenance are from the 1840s. Presumably they were used earlier, but how much earlier is unknown; the origin of the idea is lost, and glass is difficult to date. Very few original specimens remain. The Charles W. Morgan (1841), last surviving American wooden whaler and National Historic Landmark, had a single deck prism left. This ship has now been restored and is residing at Mystic Seaport.