Edison's Incandescent Lamp

Date October 21, 1879

Thomas Alva Edison’s incandescent lamp was not the first electric light to be invented, but it was the first that was practical, durable, and economical, and for that reason it made possible a world revolution in lighting and energy.

Locale Menlo Park, New Jersey

Key Figures

• Thomas Alva Edison (1847-1931), American inventor
• Moses Gerrish Farmer (1820-1893), early American experimenter with electrical lights
• Grosvenor Lowrey (fl. early nineteenth century), Western Union general counsel who encouraged Edison’s work
• J. P. Morgan (1837-1913), American financier who helped fund Edison’s experiments

Summary of Event

On October 21, 1879, Thomas Alva Edison and five associates at his laboratory in Menlo Park, New Jersey, passed one of the great milestones of modern science—a demonstration of an incandescent lamp that was at once economical, practical, and durable. The records of that day show that Edison had managed to manufacture an incandescent lamp that burned for thirteen and one-half hours. In the excitement of the discovery, notes were incomplete, and there was some talk of a bulb that burned for the then unimaginable time of more than forty hours. The light from Edison’s first successful lamp gave only a feeble, reddish glow, but Edison had set out not merely to invent a new kind of light but 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 subsequent patent application:

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 hundred 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 and low current, and sealed in a permanent high-vacuum glass to allow the burner to glow without being destroyed by the heat. The importance of Edison’s discovery is not that it was the first electric light or even the first incandescent lamp, but that it was the first electric bulb that had the potential to be universally and economically used for domestic lighting. This was especially true after Edison managed to distribute the great power generated by electrical dynamos to send it to individual users over wires. Nevertheless, when he later threw a switch at New York’s Pearl Street power station in 1882, lighting four hundred lamps for eighty-five customers, few realized that he had replaced the steam age with the electric age.

It may have been only Edison who realized the full implications of his invention. A group of Wall Street financiers headed by J. P. Morgan had eagerly bankrolled his first work in electricity but had grown weary of waiting for results. When Edison revealed to them his astonishing success, they balked at adding to their previous investments, fearing that Edison had invented a mere laboratory toy, rather than the modern electric light and power industry, which at the time of Edison’s death in 1931 would be valued in the United States alone at fifteen billion dollars.

Edison’s friend and informal financial adviser, Grosvenor Lowrey, a Western Union attorney who specialized in patents, could get no more funds from Wall Street until Edison made his early success public. The news of Edison’s invention finally reached the press on December 21, when the New York Herald announced that Edison “makes light without gas or flame, cheaper than oil.” The aesthetic importance of Edison’s lamp was captured by the Herald reporter, who described the effect as a “bright, beautiful light, like the mellow sunset of an Italian autumn.”

The triumph of the incandescent lamp was also a personal triumph for Edison. His previous major success, his invention of the phonograph in 1877, had already brought him fame. In the course of a long career, Edison would eventually be responsible for more than one thousand patents, covering inventions or improvements of the storage battery, dictaphone, ore separator, electric dynamo, electric locomotive, composition brick, Sprauge separator, compressing dies, and a forerunner of the modern motion picture projector. In pure science, Edison was responsible for the discovery of the Edison effect, which contributed to the genesis of modern electronics.

Edison’s method for inventing involved delegating authority and supervising gifted associates in a well-equipped laboratory. Most of Edison’s discoveries were collaborative ventures, but most of the imagination and creative impetus were supplied by Edison himself.

When Edison invented his incandescent lightbulb, harnessing electrical power was not itself new. Sir Humphry Davy had shown the possibility of electric illumination before the Royal Society of London in 1808. After the invention of the dynamo by Michael Faraday in 1831, electricity developed steadily but slowly. At the Philadelphia Centennial Exposition in 1876, Moses Gerrish Farmer demonstrated three large arc lights powered by a primitive transformer. Arc lighting resulted from the oxidation of carbon caused by the flow of current, which created a brilliant blue light. Incandescence relies instead upon heat applied in a vacuum to prevent the heated carbon from melting. The main problems in early incandescence concerned the supply of current and the search for a filament material that would not melt at a high temperature. Edison became fascinated by electricity after seeing Farmer’s commercial application of arc lights at Wanamaker’s Philadelphia department store in 1878.

Edison’s genius was not that of pure science; he was always interested in commercial applications. His aim with electricity was not to compete with the arc-light manufacturers but rather to duplicate the success of the gas-distributing industry by using electricity. At the time, gas lighting was a major U.S. industry with annual revenues of more than $150 million. Arc lights were expected to threaten only 10 percent of this income. Edison wanted the other 90 percent.

In this endeavor, Edison was, in effect, working from first principles, because most research in electric lighting had been devoted to the arc-light principle. He needed financing, and with confidence and gall in equal proportions, he announced before the fact that he had invented a new and cheap electric light. With W. H. Vanderbilt, Morgan, and several other prominent financiers participating, the Edison Electric Light Company was formed on October 12, 1878. It was capitalized with 3,000 shares, 2,500 of which were Edison’s. The financiers advanced $50,000 to Edison, who then proceeded to invent the light he had already announced as invented. Edison asserted that it would take only six weeks to make his lightbulb.

The fact that Edison accomplished his immediate goal in little more than one year was astonishing. However, so much publicity had preceded the actual invention that it was some time before it was taken seriously by the public or the financiers, in spite of occasional dramatic interludes, such as the lighting of all of Menlo Park, New Jersey, with the new incandescent lamp.

Significance

After actually creating the electrical lightbulb, Edison’s next challenge was demonstrating the ability of his incandescent lamp to light an entire urban area. On December 17, 1880, he founded the Edison Electric Illumination Company of New York, which evolved into Consolidated Edison. The laying of mains, the running of generators, and the convincing of a still dubious public absorbed all the inventor’s energy. However, his discovery won first prize at the 1881 Paris Electrical Exposition, and soon, patches of electrical lighting throughout the world’s cities announced the arrival of “Edison’s lamps.”

Before Edison was done, he had not only invented a successful incandescent light but had also developed an entire system to generate and distribute electric energy. Credit for bringing electricity to the world is also due to the likes of Alessandro Volta, Sir Humphry Davy, Michael Faraday, and others who had helped the realization of Edison’s more dependable, durable, and reliable system.

Bibliography

Baldwin, Neil. Edison: Inventing the Century. New York: Hyperion, 1995. This lightly illustrated account, with assistance from scores of individuals, such as Edison family descendants, is commendable for its vignettes and anecdotes. Includes a hundred pages of notes and bibliography.

Clark, Ronald W. Edison: The Man Who Made the Future. New York: G. P. Putnam’s Sons, 1977. Attractively illustrated biography illuminated with fascinating vignettes and little-known facts make this an engaging book to read. Includes an entire chapter on Edison’s invention of the lightbulb.

Dillon, Maureen. Artificial Sunshine: A Social History of Domestic Lighting. London: National Trust, 2002. Lively narrative of the impact that artificial lighting has made on human history.

Edison, Thomas A. Menlo Park: The Early Years, April 1876-December 1877. Vol. 3 in The Papers of Thomas A. Edison, edited by Robert A. Rosenberg et al. Baltimore: Johns Hopkins University Press, 1994. Includes Edison’s own early notes on an electric lighting system.

Friedel, Robert D. Edison’s Electric Light: Biography of an Invention. New Brunswick, N.J.: Rutgers University Press, 1986. History of Edison’s invention that offers a clear explanation of the origins and nature of the electric lightbulb, whose genesis was helped by William Wallace’s dynamo to generate power.

Israel, Paul. Edison: A Life of Invention. New York: John Wiley & Sons 1998. Israel draws on Edison’s notebooks to describe Edison’s working methods, portraying him as a tireless experimenter who produced his inventions with prodigious amounts of labor.

Jonnes, Jill. Empires of Light: Edison, Tesla, Westinghouse, and the Race to Electrify the World. New York: Random House, 2003. Explains how the three inventors who made the most important contributions to electrical lighting sought to create businesses that would provide safe, reliable electricity.

Josephson, Matthew. Edison: A Biography. 1959. Reprint. New York: John Wiley & Sons, 1992. Written in colorful but accessible language, this full biography is nearly encyclopedic in its coverage.

Millard, Andre. “Edison’s Laboratory and the Electrical Industry.” In Edison and the Business of Innovation. Baltimore: Johns Hopkins University Press, 1990. Well-researched and illustrated work that places the invention of Edison’s high-vacuum incandescent bulb in the broader context of the entire electrical system.

Bazerman, Charles. The Languages of Edison’s Light. Cambridge, Mass.: MIT Press, 1999. Describes how Edison and his colleagues created a system of symbols and communication to describe the new invention of electric lighting.

Wachhorst, Wyn. Thomas Alva Edison: An American Myth. Cambridge, Mass.: MIT Press, 1981. The few pages devoted to the incandescent lamp, and especially the encyclopedic Edison bibliography, are noteworthy.