Luxfer prism glass

Trade name for a type of prismatic glass with sawtooth-shaped ribs on the interior face; used in windows to refract sunlight into an interior space; typically manufactured in 4×4 or 5×5 inch squares of variously angled ribs that were assembled into larger panels; the invention of Henry Crew and Oilin Basquin was first exhibited at the Chicago World’s Fair in 1893 and commercially produced ca. 1896-ca. 1933. See also Luxfer prism. (Bucher, 1996)