Edison's Electric Light: The Art of Invention

4. The Triumph of Carbon

69 chapter four The Triumph of Carbon Much has been written about the events at Menlo Park in October of 1879, the most pivotal month in all of Edison’s work on the electric light. Despite the attention given the activity of those autumn weeks in accounts ranging from contemporary newspaper descriptions to the latest Edison biographies, many questions remain about the new turns taken by the research. The uncertainty still surrounding the developments of that October is due in no small degree to Edison and his colleagues, who chose to romanticize the activity in the many subsequent years of description and explanation —in large part, no doubt, to conform to popular notions of an inventor’s moment of triumph. Unfortunately, biographers and other scholars have also been influenced by such notions, so that most popular accounts weave together indistinguishably the threads of simplistic reminiscences, sensational journalism, romantic suppositions , and incomplete documentary evidence. Because the written record is indeed less than satisfactory, it may not be possible to do much better than make the threads of the oft-told tale of the final triumph of the incandescent light a bit more distinguishable in their varied origins and foundations. The first description of the October success was published a mere two months later, when New York Herald reporter Edwin Marshall Fox, with the cooperation of Edison and the active assistance of Upton, scored the biggest scoop of his career with his full-page story headlined “Edison’s Light: The Great Inventor’s Triumph in Electric Illumination.” The appearance of the story in the Sunday Herald of December 21, 1879, was said to have dismayed Edison, who felt it 70 edison’s electric light was premature to be put in the position of promising public demonstrations . If so, it was the first time he had shown such reticence to having the press announce his victories, real or imagined. Nonetheless , Edison later said that Fox’s account was the most accurate description published at the time. Since this account had the air of an informed insider’s view of the “triumph” and provided an obvious foundation for subsequent stories, it is worthwhile looking at Fox’s picture of the state of affairs at Menlo Park in October: The lamp, after . . . improvements, was in quite a satisfactory condition, and the inventor contemplated with much gratification the near conclusions of his labors. One by one he had overcome the many difficulties that lay in his path. He had brought up platinum as a substance for illumination from a state of comparative worthlessness to one well nigh perfection. He had succeeded, by a curious combination and improvement in air pumps, in obtaining a vacuum of nearly one millionth of an atmosphere, and he had perfected a generator or electricity producing machine (for all the time he had been working at lamps he was also experimenting in magneto-electric machines) that gave out some ninety percent in electricity of the energy it received from the driving engine. In a word, all the serious obstacles toward the success of incandescent electric lighting, he believed, had melted away, and there remained but a comparative few minor details to be arranged before his laboratory was to be thrown open for public inspection and the light given to the world for better or for worse. There occurred, however, at this juncture a discovery that materially changed the system and gave a rapid stride toward the perfect electric lamp. Sitting one night in his laboratory reflecting on some of the unfinished details, Edison began abstractedly rolling between his fingers a piece of compressed lampblack until it had become a slender filament. Happening to glance at it the idea occurred to him that it might give good results as a burner if made incandescent. A few minutes later the experi- The Triumph of Carbon 71 ment was tried, and to the inventor’s gratification, satisfactory, although not surprising results were obtained. Further experiments were made, with altered forms and composition of the substance, each experiment demonstrating that at last the inventor was upon the right track.1 Like all previous experimenters on the incandescent electric light, Edison had tried carbon very early in his work. He claimed to have tested carbonized paper as early as 1877 but found that it burned up almost immediately with even a very small current. Experimenters had met with this result as far back as Humphry...