Lamps Get Color From Ultra-Violet Rays

Popular Science, kesäkuu 1936

"Fluorescent lamps," declared fifty to 200 times as efficient as tinted incandescent bulbs, have been developed for decorative lighting effects. Ultra-violet rays, ordinaly wasted because they are invisible, are transformed into visible colored light by a chemical powder clinging to the inner glass wall of a tubular mercury-vapor lamp. Several of the lamps and the fluorescent powder are shown above. [KUVA PUUTTUU]