Thomas Edison	Nikola Tesla	George Westinghouse

Thomas Edison was born in Milan, Ohio, in 1847. Given the fame and fortune that would befall him in later life, what is remarkable about his early years is the paucity of his formal education. After all of three months, he was discharged from school for being "retarded." His cause was not helped by the partial deafness he acquired as the result of a childhood illness. His mother, herself a former school teacher, tutored him until he was twelve years old. During that time, young Thomas took an interest in chemistry and electricity. At age twelve, he went to work on railroad trains selling newspapers and candy. The odd happenings of his life are the grist of American folklore. One fateful day young Edison snatched the son a the station master from the path of an oncoming train. In a show of gratitude, the man taught Thomas the business of telegraphy. Soon he became a telegraph operator, first near his home and later in other towns in the mid-west.
By 1869 Edison was working as a telegrapher in New York’s Wall Street financial district when fate stepped in again. The newly invented stock price indicator in his office failed at a particularly critical time and Edison repaired it rather expertly. He continued working on the machine on his own and made significant improvements in its operation, selling it to Western Union as the Edison Universal Stock Printer. This transaction provided Edison with a substantial amount of working capital and established him as a clever inventor worthy of financial backing.
Ask anyone to name an important Edison invention and the reply one is likely to get is the incandescent light bulb. In fact, Edison did not invent the incandescent bulb. Rather, he brought to the device designed by others significant improvements that caused it to be of practical use to the average consumer. Before the 1860’s, the only source of electric lighting was carbon arc lighting. But this method produced very harsh lighting effects that were suitable for large spaces in auditoriums and exhibition halls. The carbon rods also produced a fair amount of smoke and odor not suitable for rooms in the average house. Bringing a substance to incandescence means heating it to the point where it gives off light. The problem is that when this is done in the presence of oxygen, the material usually ignites. This problem was solved in 1865 when Herman Sprengel, a German inventor, produced the world’s first vacuum pump. Thus, incandescence was possible and other inventors had tried to build light-producing devices, albeit with minimal success.
Edison approached the problem with keen interest. He did not wish to fabricate just any incandescent device. He wanted a bulb that had a practical use. Devices made by other inventors had very low electrical resistance, meaning they had to be used in series so that they would not draw too much current. Series connections have a built in anomaly; if one unit fails, all units in the circuit lose power. Edison realized that this was not a practical arrangement for any household use. Instead, he preferred a parallel arrangement wherein each unit could function independently of the others. However, the low-resistance units available at the time meant that the total current in the circuit would be prohibitively high. His task, then, was to find a high resistance filament that could cause bulbs to be used in parallel without drawing large amounts of current throughout the entire circuit.
It is here that Edison did something truly different. Instead of being the Lone Ranger, working in solitude in his garage, Edison launched a practice that has come to be known as research and development. In an enclave built for the task in Menlo Park, New Jersey, he assembled teams of glass blowers, electricians, vacuum pump technicians and other specialists needed for the work. Instead of proceeding through their work by guess and by gosh, Edison’s men methodically test every filament they could find under every kind of electrical condition imaginable. It is about this time and this project that Edison suggests that invention is "ninety-eight percent perspiration and two percent inspiration." Together, the Edison team spent fifteen months investigating all aspects of the light bulb problem. In December 1879, the team unveiled a bulb that burned continuously for two days before falling apart. Other improvements follow and by 1882, more than 200,000 light bulbs have been produced. The first electric sign is constructed for the Paris Exposition; the bulbs spell out the letters E D I S O N.
Throughout all of this work in electricity, Edison was steadfastly a proponent of direct current and a vigorous opponent of alternating current. Of AC he noted "My personal desire would be to prohibit entirely the use of alternating currents. They are unnecessary as they are dangerous...I can therefore see no justification for the introduction of a system which has no element of permanency and every element of danger to life and property." It is this unwavering opinion that brought his company close to the brink of financial ruin.

While Edison’s career is noteworthy because of its simple beginnings, Nikola Tesla came to science by more conventional means. He was born in 1856 in Croatia to parents who valued formal education and possessed the wherewithal to see that Nikola was well schooled. His early plans included a career in the clergy. However, as he proceeded through schools, his skill as a tinkerer and his love for mathematics sealed forever his career in science. In 1877 he entered the Polytechnic Institute in Graz, Austria and began his study of electricity. It was here that he came to study and compare the advantages and disadvantages of both alternating- and direct currents. It was clear to him, for reasons that will be mentioned later, that AC was the only practical means to use electricity in large quantities. In 1882, upon graduation for the Polytechnic, Tesla moved to Paris and was hired as an engineer by the Continental Edison Company. There he quickly impressed the American engineers sent to Europe by the Edison company to extend the electrical network there. By 1884, Tesla became obsessed with the idea of traveling to America to work with Mr. Edison himself. He came to this country in that year with pennies in his pockets and letters of introduction to Edison written by company executives in France.
Edison soon put Tesla to work on improving the efficiency of the DC dynamos that were supplying electricity in central New York City. The system had been installed hastily some years before and was prone to frequent outages. In assigning him to the project, Edison promised Tesla a bonus of $50,000 if he successfully completed the project. It took Tesla nearly a year of twenty-hour work days before he completed the project. He approached Edison to brief him about his work and to collect his bonus. "Tesla," said Edison, "you don’t understand American humor." (This is hardly the attitude that one would expect of an American icon. I do not remember Spencer Tracy speaking those words in the 1940’s film Edison: The Man.) Edison subsequently offered Tesla a raise of ten dollars to his salary of eighteen dollars per week. Tesla left the company.
Upon severance from the Edison group, Nikola Tesla was able to start his own research company and soon found the key to the polyphase alternating current motor. This was the missing piece of the AC technology puzzle.
It can be safely said that the only thing Edison and Tesla had in common was their tie to the electrical industry. While Edison was totally committed to direct current, Tesla knew that alternating current was more efficient and was likely to be adopted if an AC motor could be developed. Edison deeply resented Tesla’s formal training, calling Tesla "a poet of science" and his ideas "magnificent but utterly impractical." For his part, Tesla disliked Edison’s plodding method to problem solving which he called "empirical dragnets." Tesla said "If Edison had a needle to find in a haystack, he would proceed at once with the diligence of a bee to examine straw after straw until he found the object of his search. I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety percent of his labor.
We come now to George Westinghouse, an American inventor born in New York in 1846. Westinghouse’s father was a manufacturer of agricultural implements and this milieu proved to be the ideal place to cultivate his fertile mind. Following his service in the Civil War, George returned to New York and studied for a time at Union College in Schenectady. Subsequently, he returned to his father’s business and began a life of inventing hardware to make work easier. While he had some relatively small successes, his first major breakthrough came in 1869 when he was awarded a patent for an air brake to be used on trains. Because each car in a train had to be slowed by the manual application of mechanical brakes, trains could not travel safely at high speeds. Westinghouse’s invention caused the engineer to be able to stop all of the cars on the train will the application of a single lever. This early success in the railroad business caused him to look for other ways to make improvements in that industry. He turned his attention to the development of electrical control signals that were now necessary because of the faster-moving trains. In the 1870’s, he made improvements in the way natural gas was piped from the source to the consumer. In this application, he gradually reduced the pressure of the gas as it moved along the pipe and increased the pressure at the end. It is said that he found this method of gas distribution analogous to alternating current distribution. While his early work had little to do with electricity, his successes provided him with capital to support his future work as well as a reliable reputation among financial backers. During the 1880’s he became convinced that alternating current was an efficient way to deliver electricity and began looking for a way to exploit this technology.

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last edited 12/24/05