Patent no. 3738. Filing year 1874.

"Electric Light," Henry Woodward and Mathew Evans.

It is commonly believed that the great American inventor Thomas Edison invented the light bulb, which he patented in the United States in 1879. Edison's bulb, however, was predated by several electric light prototypes, one of which was patented in 1874 by two Canadians.

Henry Woodward was a medical student in Toronto when he and Mathew Evans (a hotel keeper described in the patent only as "gentleman") devised their electric lamp. It consisted of a pure carbon rod attached to electrodes and placed in a glass tube. Woodward and Evans pumped out the air in the tube and replaced it with a "rarified gas that [would] not unite chemically with the carbon when hot." (This gas was nitrogen.) The carbon glowed when an electric current passed through it.

Unfortunately, Woodward and Evans were unable to interest investors in their idea. In 1876, Woodward applied for a patent in the United States. Edison saw the concept's potential and in 1879 bought the patent rights from Woodward. Later, he also bought a share of the original Canadian patent. Over the next few years, Edison developed the incandescent light bulb, first using a carbon filament and then switching to bamboo. He also wanted to invent a complete electrical system, and so, in addition to the light bulb, he developed switches, fuses, electric meters and other devices.

Edison's power network got off to a slow start. His initial bulbs lasted less than 14 hours, and by 1889 his power station in New York had just 710 customers. In 1906, the General Electric Company patented the tungsten filament light bulb, which became the standard. Edison's development of a complete electrical system, however, proved to be his stroke of genius, and by 1910 more than 3 million people in the United States had electric lighting. As such, Edison's name is the one most people remember, while Henry Woodward and Mathew Evans of Toronto have become a footnote in the history of the electric light bulb.

References

Levy, Joel. Really Useful: The Origins of Everyday Things. Willowdale, Ont.: Firefly Books, 2002.

Nader, Ralph, Nadia Milleron, and Duff Conacher. Canada Firsts. Toronto: McClelland & Stewart, 1992.

Van Dulken, Stephen. Inventing the 19th Century: 100 Inventions That Shaped the Victorian Age From Aspirin to the Zeppelin. New York: New York University Press, 2001.

"Incandescent light bulb." Wikipedia.
http://en.wikipedia.org/wiki/Incandescent_light_bulb
(accessed November 9, 2005).