"These Three New Lamps Use
No More Current Than One Old One."
|Blotter number 150; image number: LAR_B150.
Text on blotter reads:
"These three new lamps use no more current than
one old one. For the same money that you now pay for current for the old-style
carbon lamp, you can now have your choice of:
3-times as much light in each roomor
3-times as many rooms lightedor
3-times as many hours of light
if, instead of the carbon lamp you use
Edison Mazda Lamps"
"Do you know the difference between the Edison Mazda
Lamp and the old-style carbon lamp? Look at the pictures. Note the difference
in the internal construction of the two kinds of lamps. Then look at your
lamp. Which kind are you using? Call on us at any time and we will gladly
show you the various sizes of Edison Mazda Lamps."
How does a company go about unselling a product after
thirty years of marketing, especially if people are happy with that product?
General Electric and other lamp makers found themselves faced with just
that task in the years around 1910 as they introduced metal-filament lamps
into the market.
The new lamps could operate at higher temperatures
than older carbon lamps and so gave better energy efficiency (at
higher tempertures more radiation is emitted as light and less as heat).
Lamps made with tungsten
produced about 12 lumens per watt compared to about 4 lpw for the
best carbon lamps. The tungsten lamps were more expensive to buy however,
and for many years people continued to purchase cheaper carbon lamps.
The blotter seen above shows GE emphasizing the advantages
of higher efficiency by focusing on the cost of current. Sellers of compact
fluorescent lamps today have a very similar problem and follow much the
For additional information about carbon
and tungsten lamps see:
Arthur A. Bright, Jr., The Electric-Lamp
Industry: Technological Change and Economic Development from 1800 to 1947
(New York: MacMillan Co., 1949)
Brian Bowers, Lengthening the Day
(New York: Oxford University Press, 1998)
John W. Howell and Henry Schroeder, History
of the Incandescent Lamp (The Maqua Co., 1927)