Thomas Alva Edison – born February 11, 1847, Milan, Ohio, U. S. d. Oct. 18, 1931, West Orange, N. J. American inventor who, singly or jointly, held a world record 1,093 patents. In addition, he created the world’s first industrial research laboratory. Edison was the quintessential American inventor in the era of Yankee ingenuity. He began his career in 1863, in the adolescence of the telegraph industry, when virtually the only source of electricity was primitive batteries putting out a low-voltage current. Before he died, in 1931, he had played a critical role in introducing the modern age of electricity.
From his laboratories and workshops emanated the phonograph, the carbon-button transmitter for the telephone speaker and microphone, the incandescent lamp, a revolutionary generator of unprecedented efficiency, the first commercial electric light and power system, an experimental electric railroad, and key elements of motion-picture apparatus, as well as a host of other inventions. Edison was the seventh and last child–the fourth surviving–of Samuel Edison, Jr. , and Nancy Elliot Edison. At an early age he developed hearing problems, which have been variously attributed but were most likely due to a familial tendency to mastoiditis.
Whatever the cause, Edison’s deafness strongly influenced his behaviour and career, providing the motivation for many of his inventions. Early years In 1854 Samuel Edison became the lighthouse keeper and carpenter on the Fort Gratiot military post near Port Huron, Mich. , where the family lived in a substantial home. Alva, as the inventor was known until his second marriage, entered school there and attended sporadically for five years. He was imaginative and inquisitive, but because much instruction was by rote and he had difficulty hearing, he was bored and was labeled a misfit.
To compensate, he became an avid and omnivorous reader. Edison’s lack of formal schooling was not unusual. At the time of the Civil War the average American had attended school a total of 434 days–little more than two years’ schooling by today’s standards. In 1859 Edison quit school and began working as a trainboy on the railroad between Detroit and Port Huron. Four years earlier, the Michigan Central had initiated the commercial application of the telegraph by using it to control the movement of its trains, and the Civil War brought a vast expansion of transportation and communication.
Edison took advantage of the opportunity to learn telegraphy and in 1863 became an apprentice telegrapher. Messages received on the initial Morse telegraph were inscribed as a series of dots and dashes on a strip of paper that was decoded and read, so Edison’s partial deafness was no handicap. Receivers were increasingly being equipped with a sounding key, however, enabling telegraphers to “read” messages by the clicks. The transformation of telegraphy to an auditory art left Edison more and more disadvantaged during his six-year career as an itinerant telegrapher in the Midwest, the South, Canada, and New England.
Amply supplied with ingenuity and insight, he devoted much of his energy toward improving the inchoate equipment and inventing devices to facilitate some of the tasks that his physical limitations made difficult. By January 1869 he had made enough progress with a duplex telegraph (a device capable of transmitting two messages simultaneously on one wire) and a printer, which converted electrical signals to letters, that he abandoned telegraphy for full-time invention and entrepreneurship.
Edison moved to New York City, where he initially went into partnership with Frank L. Pope, a noted electrical expert, to produce the Edison Universal Stock Printer and other printing telegraphs. Between 1870 and 1875 he worked out of Newark, N. J. , and was involved in a variety of partnerships and complex transactions in the fiercely competitive and convoluted telegraph industry, which was dominated by the Western Union Telegraph Company. As an independent entrepreneur he was available to the highest bidder and played both sides against the middle.
During this period he worked on improving an automatic telegraph system for Western Union’s rivals. The automatic telegraph, which recorded messages by means of a chemical reaction engendered by the electrical transmissions, proved of limited commercial success, but the work advanced Edison’s knowledge of chemistry and laid the basis for his development of the electric pen and mimeograph, both important devices in the early office machine industry, and indirectly led to the discovery of the phonograph.
Under the aegis of Western Union he devised the quadruplex, capable of transmitting four messages simultaneously over one wire, but railroad baron and Wall Street financier Jay Gould, Western Union’s bitter rival, snatched the quadruplex from the telegraph company’s grasp in December 1874 by paying Edison more than $100,000 in cash, bonds, and stock, one of the larger payments for any invention up to that time. Years of litigation followed.
Although Edison was a sharp bargainer, he was a poor financial manager, often spending and giving away money more rapidly than he earned it. In 1871 he married 16-year-old Mary Stilwell, who was as improvident in household matters as he was in business, and before the end of 1875 they were in financial difficulties. To reduce his costs and the temptation to spend money, Edison brought his now-widowed father from Port Huron to build a 2 1/2-story laboratory and machine shop in the rural environs of Menlo Park, N. J. –12 miles south of Newark–where he moved in March 1876. Accompanying him were two key associates, Charles Batchelor and John Kruesi. Batchelor, born in Manchester in 1845, was a master mechanic and draftsman who complemented Edison perfectly and served as his “ears” on such projects as the phonograph and telephone. He was also responsible for fashioning the drawings that Kruesi, a Swiss-born machinist, translated into models.
Edison experienced his finest hours at Menlo Park. While experimenting on an underwater cable for the automatic telegraph, he found that the electrical resistance and conductivity of carbon (then called plumbago) varied according to the pressure it was under. This was a major theoretical discovery, which enabled Edison to devise a “pressure relay” using carbon rather than the usual magnets to vary and balance electric currents.
In February 1877 Edison began experiments designed to produce a pressure relay that would amplify and improve the audibility of the telephone, a device that Edison and others had studied but which Alexander Graham Bell was the first to patent, in 1876. By the end of 1877 Edison had developed the carbon-button transmitter that is still used in telephone speakers and microphones. The phonograph Edison invented many items, including the carbon transmitter, in response to specific demands for new products or improvements.
But he also had the gift of serendipity: when some unexpected phenomenon was observed, he did not hesitate to halt work in progress and turn off course in a new direction. This was how, in 1877, he achieved his most original discovery, the phonograph. Because the telephone was considered a variation of acoustic telegraphy, Edison during the summer of 1877 was attempting to devise for it, as he had for the automatic telegraph, a machine that would transcribe signals as they were received, in this instance in the form of the human voice, so that they could then be delivered as telegraph messages.
The telephone was not yet conceived as a general, person-to-person means of communication. ) Some earlier researchers, notably the French inventor Lon Scott, had theorized that each sound, if it could be graphically recorded, would produce a distinct shape resembling shorthand, or phonography (“sound writing”), as it was then known. Edison hoped to reify this concept by employing a stylus-tipped carbon transmitter to make impressions on a strip of paraffined paper.
To his astonishment, the scarcely visible indentations generated a vague reproduction of sound when the paper was pulled back beneath the stylus. Edison unveiled the tinfoil phonograph, which replaced the strip of paper with a cylinder wrapped in tinfoil, in December 1877. It was greeted with incredulity. Indeed, a leading French scientist declared it to be the trick device of a clever ventriloquist. The public’s amazement was quickly followed by universal acclaim.
Edison was projected into worldwide prominence and was dubbed the Wizard of Menlo Park, although a decade passed before the phonograph was transformed from a laboratory curiosity into a commercial product. The electric light Another offshoot of the carbon experiments reached fruition sooner. Samuel Langley, Henry Draper, and other American scientists needed a highly sensitive instrument that could be used to measure minute temperature changes in heat emitted from the Sun’s corona during a solar eclipse along the Rocky Mountains on July 29, 1878.
To satisfy those needs Edison devised a “microtasimeter” employing a carbon button. This was a time when great advances were being made in electric arc lighting, and during the expedition, which Edison accompanied, the men discussed the practicality of “subdividing” the intense arc lights so that electricity could be used for lighting in the same fashion as with small, individual gas “burners. ” The basic problem seemed to be to keep the burner, or bulb, from being consumed by preventing it from overheating.
Edison thought he would be able to solve this by fashioning a microtasimeter-like device to control the current. He boldly announced that he would invent a safe, mild, and inexpensive electric light that would replace the gaslight. The incandescent electric light had been the despair of inventors for 50 years, but Edison’s past achievements commanded respect for his boastful prophecy. Thus, a syndicate of leading financiers, including J. P.
Morgan and the Vanderbilts, established the Edison Electric Light Company and advanced him $30,000 for research and development. Edison proposed to connect his lights in a parallel circuit by subdividing the current, so that, unlike arc lights, which were connected in a series circuit, the failure of one light bulb would not cause a whole circuit to fail. Some eminent scientists predicted that such a circuit could never be feasible, but their findings were based on systems of lamps with low resistance–the only successful type of electric light at the time.
