Some late Victorian Luxfer prism lights are for sale in the latest news email from Retrouvius in Kensal Rise. Prism lights had an unusual history of development by a US inventor working in London, and an English inventor working in Boston - both of whom would have been familiar with long sea voyages and early deck prism lights.
 
The Luxfer Prism Company was started in Chicago in October 1896 as the Radiating Light Company which became the Semi Prism Glass Company. They were all founded by James G. Pennycuick to commercialize his patent 247996 of 1881 for horizontal illuminating semi-prism glass tiles, and patent 312290, filed in 1882 and issued in 1885, for vertical plain small window panes with added horizontal strip prisms to direct sunlight to the interiors of shops and basements with open wells or areas. Patent 312290 states:
 
The nature of my invention consists in the construction of window-glass,whereby the reflection of the light into the room is considerably increased without increasing the size of the window. As a new article of manufacture, a window glass one side of which has a plane surface, while the opposite side is formed with a series of ribs, each of which is formed on one side with a surface at practically a right angle to the body of the glass, while its opposite side is inclined at less than a right angle, substantially as set forth.(see patent illustration)
In 1897 the company name was changed again to the Luxfer Prism Company. Luxfer means 'light bearer' in Latin and the glass tiles were marketed as 'daylighting' tiles to great acclaim in the building world. In the same year Frank Llpyd Wright (1867-1959) was commissioned to design glass tiles for Luxfer and took out over 40 design patents for embossed pattern glass prism tiles many with circles and arcs of circles, typical of FLW at the time. FLW's design copyright stated that it had lines of ornamentation produced upon the prism-light by variations in the surface-levels. These ornamental lines take the form of circles, arcs of circles, squares, and the like, arranged concentrically about the center C and interlacing or overlapping each other. The whole forms a grid-like sort of ornament
 
Luxfer syndicate businesses were established by the British Luxfer Syndicate followed by France, Belgium and Germany and Louis Sullivan used Luxfer in the new Carson Pirie Scott Chicago department store.
 
By the 1930s, with the advent of electric lighting, Luxfer Ltd in Britain had diversified into steel windows and other products inlcuding tubing for Hoovers, prefabs, shell casings, bazookas and gas cylinders, and prism glass production ceased.
 
The Retrouvius lights comprise of several pieces and the website description does not claim its tiles to be by Frank Lloyd Wright. However one set seems obviously by FLW with simply the circle and 'petal' part of the more familiar well-known and complex 'flower' motif which is definitely his. The second tile is simpler still with a square imposed as a diamond over a square dogstooth, aka quilted, background.
 
- - - - - - - - -
DECK PRISM LIGHTS: Deck prism lights were introduced in the early 1800s, initially as removable bulls-eyes, as an improvement to plain glass horizontal portholes which were a way of illuminating the interiors of small ships, especially at night when naked flames were a fire hazard and when, apparently, lamps would be located above the prisms on deck. At night, it was said that prism lights could also alert crew to fire in the hold of a collier. Prism deck lights seemed not to have caught on in a big way and were not common on ships until the 1850s. It was hard to find professional wick trimmers who understood how to clean silvered reflectors, and the prisms had limited ability to light below deck spaces.
 
The technology of refracting light using deck prism lights and the dioptric lenses used in lighthouses were first brought on to land in the US and UK in the form of pavement lights made by US inventor and abolitionist Thaddeus Hyatt of London-based Hyatt Brothers and Hayward Brothers foundry of Borough, London.