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Emil P. Spahn/Library of Congress
Thomas Edison pictured in 1880

On This Day: Thomas Edison Develops Incandescent Light Bulb

October 21, 2011 06:00 AM
by findingDulcinea Staff
On Oct. 21, 1879, Thomas Edison completed a successful experiment with his electric lamp, which, along with his development of power systems, revolutionized the use of electric light.

Edison’s Light Bulb

Edison began working on electric light in September 1878 and developed his first incandescent lamp in January 1879. However, like the efforts of many previous scientists, Edison’s lamp worked for only a short time and was therefore impractical for everyday use.

Edison and his team of scientists worked on developing a more effective vacuum for their bulb and experimented with different sources for the lamp filament. “Before I got through. I tested no fewer than 6,000 vegetable growths, and ransacked the world for the most suitable filament material,” he recalled.

Edison closely studied the work of English chemist Joseph Swan, whose bulb used a carbon rod that burned up quickly and required large amounts of electricity to work. The Edison team’s improved vacuum created an atmosphere within the bulb that allowed carbon to last much longer.

Edison further improved upon the design by creating a carbonized filament of cotton thread. This breakthrough was described in an article in the New York Herald on Dec. 21, 1879: “Sitting one night in his laboratory reflecting on some of the unfinished details, Edison began abstractedly rolling between his fingers a piece of compressed lampblack until it had become a slender thread. Happening to glance at it the idea occurred to him that it might give good results as a burner if made incandescent.”

In Edison’s Oct. 21-22 experiment, his new light bulb lasted for about 14 hours being burning out. He applied for a patent for an “Improvement in Electric Lamps” and continued improving his bulb. In early 1880, he learned that a carbonized bamboo filament could last 1,200 hours.

Perhaps equally as important as the development of the improved bulb was Edison’s development of an electrical supply system to power the bulbs. He created a direct-current system based the existing gas lighting systems, which supplied power through central stations and underground conductors.

Edison’s contribution to electric lighting wasn’t its invention, but its development,” says John Lienhard, mechanical engineering and history professor at the University of Houston. “There is no single inventor of any great technology. Ideas rise out of a whole community. But people who can put full-blown systems together are rare. And in that sense, maybe it is fair to say that Edison invented the light bulb, after all.”

Biography: Thomas Alva Edison

Thomas Alva Edison was born on Feb. 11, 1847, in Milan, Ohio. When he was 7 years old he moved with his family to Michigan. He left home at age 16, having had little formal education. He settled in Boston briefly, where he successfully applied for his first patent in 1868, for an electric vote recorder.

A year later, Edison moved to New York City, and then onward to Menlo Park, N.J., where he stayed for the rest of his career. His first invention to get major press coverage was the phonograph, built in 1877.

It “made Edison’s reputation as the ‘Inventor of the Age’ and led to his most famous nickname ‘The Wizard of Menlo Park,’” according to Rutgers University. “Newspaper reporters flocked to the Menlo Park Laboratory to see the new invention and to interview Edison. A constant stream of articles about the inventor, including anecdotes and biographical sketches, led to his becoming one of the most famous men in the world.”

In the 1890s, he further developed the phonograph and unveiled the motion picture. His alkaline battery came along in 1899. By this point, his fame and his position as a cultural icon were well established.

In “The Wizard of Menlo Park: How Thomas Alva Edison Invented the Modern World,” author Randall Stross argues that Edison, in addition to his other accomplishments, was the first to imbue business with celebrity status.

No one of the time would have predicted that it would be an inventor, of all occupations, who would become the cynosure of the age,” writes Stross. “In retrospect, fame may appear to be a justly earned reward for the inventor of practical electric light in 1879—yet Edison’s fame came before light. It was conferred two years earlier, for the invention of the phonograph. Who would have guessed that the announcement of the phonograph’s invention was sufficient to propel him in a matter of a few days from obscurity into the firmament above?”

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