Edison Demonstrates the Incandescent Lamp (Great Events from History: North American Series)
Article abstract: A workable electric bulb gives birth to a revolution in lighting and energy.
Summary of Event
On October 21, 1879, Thomas A. Edison and five associates at his laboratories in Menlo Park, New Jersey, passed one of the great milestones of modern science—a demonstration of an incandescent lamp that was economical, practical, and durable. The records of that day show that Edison had managed to manufacture an incandescent lamp that burned for thirteen and a half hours. In the excitement of the discovery, notes were incomplete, and there was some talk of a bulb that burned for the unheard-of time of more than forty hours. The light from Edison’s first successful lamp gave a feeble, reddish glow, but Edison had set out not merely to invent a new kind of light but rather to revolutionize the science of illumination and to bring electricity within the means of everyone.
The secret of Edison’s incandescent lamp is best explained in his patent application (No. 223.898, January 27, 1880): “I have discovered that even a cotton thread, properly carbonized and placed in a sealed glass bulb, exhausted to one-millionth of an atmosphere, offers from one hundred to five hundreds ohms resistance to the passage of current and that it is absolutely stable at a very high temperature.” Edison had made an incandescent lamp with a hairlike carbon filament for a burner, having the necessary high resistance...
(The entire section is 1465 words.)
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