History of Edison’s Light Bulb
The history of Edison’s light bulb is a story of slow innovation. Many people think of Thomas Edison as the father of light bulb. In fact, many people were involved in inventing ways to produce, transmit, and use electricity. If we look at the patent issued to him, we can read that Edison did not patent the light bulb. What he patented was actually “…an Improvement in Electric Lamps and in the method of manufacturing the same…”. This means that the Electric Lamp already existed, and he had found a way to improve it. It turns out that Edison’s improvement was crucial to the commercial success of the light bulb (and to electricity), because previous incarnations had not been viable. They would work at most for a few hours and then need to be replaced. If the light bulb was going to replace the kerosene lantern as the way people lit their homes after dark, then it would have to be at least as practical.
The first incandescent bulb was actually demonstrated in 1802 in England by chemist Humphry Davy, 45 years before Thomas Edison was born. Davy’s light bulb used a platinum filament because platinum has a high melting point (maybe one reason it’s also used in catalytic converters in cars). Davy’s bulb didn’t generate enough light to be useful, and the platinum filament would burn up in a short time.
Platinum continued to be used through about 1845 when John Starr pursued patents in the U.S. and England for an incandescent light using a carbon filament. Starr’s design also allowed the filament to be replaced when it burned out, so a new bulb wasn’t needed, just the filament.
British scientist Joseph Swan was the first to successfully demonstrate and patent an incandescent light using carbon. Instead of using a filament design, he used carbon rods. Forcing a large amount of electricity through the rods caused an arc to form between them (similar to a Tesla coil). The amount of energy needed to cause the lamp to arc required the use of very large wires. The design wasn’t commercially viable. Swan is typically credited as being the first to patent the light bulb. He started his research in earnest in 1878, and the patent was issued in Britain in 1880. His bulbs lasted over 13 hours, to give you some idea of where the state of the art was at that time.
At the same time (1878) in America, Thomas Edison started to work on solving the same problem – a commercially viable light bulb. Edison experimented with carbon, platinum, and literally thousands of other materials looking for the right solutions. He eventually settled on carbon combined with a vacuum environment. After 2 years, in 1880, he was able to submit his patent for what was now an improvement to the now 78 year old idea of the light bulb.
It would still be another 13 years before light bulbs were shown to the world as a viable alternative to kerosene lamps. The big debut was at the World’s Fair in 1893, where close to 100,000 bulbs lit up the fair at night. Even those bulbs had to be replaced throughout the night, the technology had not come far enough that they would last all night. Edison wasn’t responsible for the display at the World’s Fair. His company, Edison Electric, lost the bid to Westinghouse, which had Nikola Tesla at the inventive helm.
The story behind Edison’s rise in the electricity business, backed (and really pushed) by J.P. Morgan, along with their competition with Westinghouse and Tesla is a fascinating one. In fact, patent royalties almost prevented America from having electricity available to the masses. The History Channel did an amazing mini-series which includes this story, and we highly recommend it. It’s called The Men Who Built America (available on amazon.com). It’s worth owning, as you’ll want to watch it more than once, and at your own pace.