Early Light Bulbs
Early Light Bulbs
- Page created by SHH, 10 September 2008
- Contributors: SHH x2, Nbrewer x4, Nmolnar x1, Jvv x1, Administrator1 x4
- Last modified by Administrator1, 10 September 2012
De la Rue’s platinum bulb worked, but platinum was far too expensive to use in commercial light bulbs. Thomas Edison, after investigating many different filament materials, settled on carbon filament in 1879. At about the same time, an English inventor named Joseph Swan came up with almost the same idea, leading to claims that it was he who really invented the light bulb. Clearly, no single inventor deserves sole credit for the light bulb. What was unique about Edison’s work was that he carried the idea from laboratory to commercialization, taking into consideration not only technical problems, but also issues like economics and the production of bulbs.
A lamp used at the historic 1879 New Year’s Eve demonstration of the Edison Lighting System in Menlo Park, New Jersey. Courtesy: The Henry Ford Museum and Greenfield Village.
Edison’s carbon filament gave his lighting system an inexpensive bulb, and also the carbon filament worked well at about 110 volts, which Edison considered an economical and safe voltage for the distribution of electricity. In the original Edison and Swan bulbs, the filament was made by burning a cotton thread until all that was left was black carbon. However, the resulting filament was fragile, so Edison later substituted a burned bamboo filament (another idea that had been tried earlier). Combined with the use of an improved vacuum pump to clear more air out of the bulbs, this gave his lamps a maximum lifetime of approximately 1200 hours, versus only 14 or so for the cotton filament bulb.