The Edison Papers team has been able to find little evidence to support the view that inspiration again and again struck Edison like lightning bolts out of the blue. Take Edison's widely repeated account of a carbon-filament light bulb that burned forty hours straight as his associates watched, transfixed by the miracle. That episode, dramatized in a Hollywood film starring Spencer Tracy as the great inventor, never really happened. Scrutinizing the notebooks from that period, the scholars discovered that the bulb burned only fifteen and a half hours. According to Paul Israel, a historian preparing a biography of Edison based on the archival endeavor, the team's version of that exciting event became inflated after subsequent tests of other carbon-filament materials confirmed the general approach. "The whole 'Eureka!' story arose afterward, probably because they needed a date for the anniversary of the electric light," Israel theorizes. "So they cast their minds back, and suddenly a fifteen-hour bulb became a forty-hour bulb."
A casual reading of Edison's notebooks leaves one with the impression that Eureka! moments were frequent in the laboratory. That's because Edison tended to become wildly enthusiastic about virtually any quirky or unaccountable phenomenon--from the unexpected deflection of a galvanometer needle during an electrical experiment to his discovery on his daily walk around the lab grounds of a bug emitting an unusual odor (this so fascinated the inventor that he wrote to Charles Darwin about it). Yet the project team can identify only a few Eureka! moments that actually had valuable results over Edison's long and illustrious career, and only one--the discovery of the principles behind the phonograph--that deserves the mythic importance with which the public invests such events.
A classic spinoff, the phonograph emerged unbeckoned from work on telegraphs and telephones. In the interest of efficiency, the American mode of telegraphy used receiving instruments that produced a series of clicks, which operators mentally translated into letters. The clicks themselves left no lasting trace. In 1876 Edison and his associates developed a telegraph recorder that would emboss a message on paper, so that it could be transmitted repeatedly at high speed and a receiving operator could rerun it more slowly for transcription. One July day in 1877 Edison considered using a very similar technique for recording telephone messages. The next day he realized that he could dispense with the electrical message, directly emboss the vibrations of the original sounds, and replay them for a simulacrum of the speaker's voice. This flash of insight paved the way for the modern recording industry.
Why, given that major inventions seldom emerge as revelations, was Edison so effective? The Edison Papers Project scholars can point to attitudes, work habits, and methods of reasoning that clearly contributed to his prolific output.
In Israel's view, perseverance was a cornerstone of Edison's strength. This idea is captured in his famous proclamation, "Invention is ninety-nine percent perspiration, and one percent inspiration." In Victorian-era America, of course, hard work and determination were commonly invoked to explain the self-made man. But the recent scholarship casts doubt on the inventor's clever but ultimately facile account of his own genius, addressing such fundamental issues as what enabled him to push ahead in the face of numerous setbacks and how exactly he learned from failure.
Edison could not conceive of any experiment as a flop. As Israel puts it, "He saw every failure as a success, because it channeled his thinking in a more fruitful direction." Israel thinks that Edison may have learned this attitude from his enterprising father, who was not afraid to take risks and never became undone when a business venture crumbled. Sam Edison would simply brush himself off and embark on a new moneymaking scheme, usually managing to shield the family from financial hardship. Israel says, "This sent a very positive message to his son--that it's okay to fail--and may explain why he rarely got discouraged if an experiment didn't work out." In addition to teaching him what wouldn't work, Israel says, failed experiments taught him the much more valuable lesson of what would work--albeit in a different context.
Very few challenges failed to yield to Edison's brute intelligence, but one that did ultimately defeat him was the undersea telegraph. To help his experiments, Edison designed a laboratory model of a transatlantic cable, in which cheap powdered carbon was used to simulate the electrical resistance of thousands of miles of wires. Alas, the rumble of traffic outdoors, clattering in the machine shop, or even the scientists' footsteps shook the equipment enough to change the pressure of the connecting wires on the carbon, thus altering its resistance. Since the accuracy of the model depended upon constant resistance in the carbon, Edison finally abandoned this approach. But later, when confronted with the problem of how to improve the transmission of voices over the telephone, he used a funnel-shaped mouthpiece to focus sound waves on a carbon button. The pressure of those vibrations altered the resistance in the circuit in synchrony with the speaker's voice. In other words, what ruined Edison's underwater-telegraphy experiments is exactly what made his telephone transmitter such a triumph. Indeed, this innovative transmitter rendered Alexander Graham Bell's telephone practical--so much so that it remained the industry standard for a century.
Edison viewed even disasters as an opportunity for learning. On one occasion his lab stove went out in the dead of winter, causing an assortment of expensive chemicals to freeze. On another occasion unprotected chemicals were damaged by sunlight. Instead of bemoaning the losses, Edison put aside all other projects to catalogue changes in the properties of the bottled substances. Keith Nier observes, "He knew how to turn lemons into lemonade."
In his memoirs, and certainly before the press, Edison projected the image of a no-nonsense workaholic. In various respects he lived up to this reputation, often working as many as 112 hours a week. His second wife, Mina, had a cot set up in a corner of his library so that he could take catnaps in a more dignified manner than stretching out on the laboratory bench, as had been his habit. Yet this hard-driving man also had a childlike sense of curiosity and a fun-loving streak that could not always be contained in his rush to meet deadlines and achieve goals.
Perhaps the most delightful document yet unearthed by the project editors is one that captures a giddy moment in the lab during a marathon work spell, when Edison and his colleagues behaved with the goofy abandon of high school kids set loose in chemistry class. Searching for a liquid with specific properties for an electrochemical device, they tried caraway oil, clove oil, oregano oil, nitrogen chromate, and peppermint oil. But as night stretched on into the wee hours of the morning, they adopted a more freewheeling approach. The next notebook entry records that they tested coffee, eggs, sugar, and milk.
Breakfast was scarcely the most exotic material to be harnessed during the course of experimentation. Whale baleen, a tortoise shell, elephant hide, and the hair of a native Amazonian are just a few of the items collected by Edison in his obsessive quest for compounds with unique properties. One of his colleagues joked that his lab storeroom held everything, including "the eyeballs of a US senator." Although most of these substances had no practical applications, a few did. Rain-forest nuts were compressed into bricks from which Edison made phonograph needles. Japanese bamboo was fashioned into a filament for his commercial light. As for the Amazonian's hair, it came in handy as a wig for the first talking doll, in whose chest was concealed a tiny phonograph speaker.