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1939 - a new glare-free bulb, known as the Wabash Superlite, was developed by the Wabash Appliance Corporation of Brooklyn


CD 1964003 E&MP25.056

Electric Lamps

January 15, 1939

Lighting engineers this month welcomed a new type of glare-free electric light bulb, called the most revolutionary improvement in incandescent lamps since the appearance in 1925 of the common inside frosted bulb.

The new bulb, known as the Wabash Superlite, was developed by the Wabash Appliance Corporation of Brooklyn, this country’s largest independent lamp manufacturer and is specially designed to act as its own diffuser in changing ordinary harsh filament light into soft restful illumination, without losing any light in doing so, and with complete elimination of glare.

Contrary to popular conception, Wabash engineers point out that the glare problem during the last decade has been getting worse instead of better, because lamp engineers have paid too much attention to lamp efficiencies and not enough to lamp glare.

Since 1925, lamp manufacturers have increased lamp efficiencies many times, but have done nothing about increased filament brightness which has resulted in the sharp, harsh glare-spot of light seen in the center of the ordinary bulb.

This fiery glare spot, no bigger than a half dollar, has been shown by laboratory tests to be more than forty times brighter than the rest of the bulb surface, and has caused illumination experts much concern - as is evidenced by the widespread use of outside diffusing globes and devices designed to soften the glare-spot and condition the light.

According to Wabash, the new Superlite introduces light-conditioning in the bulb itself, producing soft, restful, surprisingly white illumination without the need for extra diffusing equipment or extra current. A new treatment on the inside of the glass breaks up the harsh raw light rays of the filament into millions of soft, counter-diffusing light rays which are perfectly diffused over the entire bulb surface, and transmitted through the glass without loss of any light.

Thus the filament-fire spot is eliminated, glare is stopped inside the bulb, and the light comes through perfectly conditioned for reading and working. The new Wabash Superlite seems to supply the kind of conditioned light illumination engineers were after when they designed diffusing equipment, and is expected to find wide use in home, office and factory lighting. All sizes from 15 watts to 300 watts are now in commercial production.  

Original Caption by Science Service
Wabash Appliance Corporation

National Museum of American History


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