The Spark of Genius
Thomas Edison created the first light bulb 125 years ago. But he was not only America's greatest inventor. He was also a master entrepreneur
Success. After two sleepless weeks, Edison relieved the carbon rollers. His new idea was to bake the carbon into a length of plain cotton thread. On the eighth attempt, on October 21, the dexterous Batchelor held his breath carrying a tiny thread bent into the shape of a horseshoe to Boehm's house for insertion in a bulb. "Just as we reached the glass blower's house, the wretched carbon broke," Edison recalled. "We turned back to the main laboratory and set to work again. It was late in the afternoon before we produced another carbon, which was broken by a jeweler's screwdriver falling against it. But we turned back again and before nightfall the carbon was completed and inserted in the lamp. The bulb was exhausted of air and sealed, the current turned on, and the sight we had so long desired to see met our eyes."
Thread No. 9, lit at 1:30 a.m., lasted until 3 p.m.--13 1/2 hours, whereupon Edison added a stronger battery to boost the light to 30 candles, or three times gaslight. They watched the tiny filament struggle with the intense heat. The light continued for 60 minutes. It was a crack in the glass that turned the room back into darkness--amid the cheers of exhausted men. They had proved that a carbon filament in a vacuum would work.
After examining the charred filament under a microscope, Edison launched another search for an organic fibrous material, some form of cellulose that might yield even more resistance than cotton. By November 16, they settled on a piece of common cardboard. Edison records: "None of us could go to bed, and there was no sleep for any of us for 40 hours. We sat and watched it with anxiety growing into elation. The lamp lasted about 45 hours, and I realized that the practical incandescent lamp had been born."
Already, Edison was preparing to establish electric beach-heads in New York, Paris, and London. The lab staff worked frantically making bulbs by hand, one by one, so that on New Year's Eve, when Edison opened Menlo Park to a public exhibition, he had around 300 bulbs. Some 3,000 people came to gaze and put questions to the great man. Still, the experts in America and England refused to be dazzled. Henry Morton of the Stevens Institute, who had been on the Rockies expedition, charged that Edison was perpetrating "a fraud upon the public," provoking Edison to make another promise: He would erect a statue of Morton at Menlo Park and shine an eternal electric light on his gloomy countenance.
What Edison attempted next can be characterized only as awesome, as if having climbed Everest he sprouted wings and flew from the top. "There is a wide difference," he said, "between completing an invention and putting the manufactured article on the market," but marketing an electric light bulb was the least of it. He had to invent the electrical industry. He had to conceive a system down to its very last detail--and then manufacture everything in it. He had to build a central power station; design and manufacture his own dynamos to convert steam power into electrical energy; ensure an even flow of current; connect a 14-mile network of underground wiring; insulate the wiring against moisture and the accidental discharge of electrical charges; install safety devices against fire; design commercially efficient motors to use electricity in daylight hours for elevators, printing presses, lathes, fans, and the like; design and install meters to measure individual consumption of power; and invent and manufacture a plethora of switches, sockets, fuses, distributing boxes, and lamp holders.