Why should humanists, scientists, engineers, policymakers, students, and lay people want to examine or study Edison’s personal and business correspondence, legal agreements, laboratory notebook entries, and patent materials? Since he has been the subject of dozens of biographies, what more need be said about this inventive genius? Every American school child knows about him. He is among the small pantheon of national heroes that includes Washington, Jefferson, and Lincoln. While generations of historians have studied the writings of such august political figures and written profusely about them, only a small number of scholars have examined the creative thinking of one of the most heralded inventors in history¹ or the activities of less prominent technical people who nevertheless are regarded as central to the emergence of the United States as a world industrial leader in the twentieth century. Few have passed through the doors of the Edison archives; fewer have probed its rich resources. Consequently, most people continue to harbor the simplistic views of Edison and invention that are perpetuated in popular biographies.² Yet this is a time when an informed understanding of technical creativity and innovation is vital for technical and business leaders, policymakers, and the electorate, whose decisions will shape the world of the twenty-first century.

Unfortunately, misleading views of Edison and of technical creativity persist. How many think of the young Tom Edison as an addled youngster and a country bumpkin? How common is the view of him as an unsophisticated businessman who went to the big city not knowing how to cash a check or drive a good bargain with the sharks of Wall Street; as the lone inventorPage xxix or wizard who single-handedly made miraculous inventions; as an uneducated tinkerer who used “cut-and-try” methods, mindlessly tested everything, bumbled onto technical breakthroughs, and, by a streak of luck, transformed the world; and as the white-haired, grandfatherly old gent who was at once miraculously prolific, personally affable, and a symbol of benign technology? How ingrained is the view of nineteenth-century invention as the product of the inspired insight of the isolated tinkerer?

In this first volume of Edison’s papers, his own early documents challenge traditional interpretations of his epochal position in world history and suggest new ways of understanding technical creativity and innovation. These documents address such important issues as (1) the character and extent of Edison’s education; (2) his relationship to the national and international technical and scientific communities; (3) his entrepreneurial instincts and business acumen; (4) the source of the problems he and his contemporaries sought to solve; (5) his inventive methods and style; (6) the role of his early technical and business experience in giving direction to his inventive career; and (7) the relationship of his work to that of other inventors. Let us briefly consider what the documents of this volume suggest about these issues.

Edison, like most of his American contemporaries, received limited formal education, but through his reading and experience he acquired a broad and detailed understanding of the society in which he lived. He attended two schools, where he learned the rudiments of reading, writing, and science. He also received intellectual stimulation from the instruction given him by his mother, a former teacher, and from the ideas and small home library of his politically radical father. By age fifteen he was frequenting the library at the Detroit Young Men’s Society, and writing and printing his own newspaper, the Weekly Herald. As an itinerant telegrapher in his late teens, he systematically read newspapers, frequented public libraries, developed a beautiful handwriting, and gained a reputation as an excellent press-wire receiver for the Western Union Telegraph Company. These achievements not only attest to his coding and verbal skills and discount claims that he was dyslexic but also confirm his recollections that he commanded the details of the daily news of politics and business.

Significantly, the hearing-impaired young inventor learned to exploit the work of varied technical communities. He knewPage xxx the machine shops, read the telegraph journals and manuals, and used libraries to find scientific and technical ideas and data. Before he was twenty, he knew of the technical works of Michael Faraday and Robert Sabine as well as the Proceedings of the Royal Society of London. His 1868 correspondence with John Van Duzer reveals his detailed knowledge of European telegraph design. Far from being a lone inventor, this shrewd young man joined an existing community of telegraph inventors and learned to exploit publications of the national and international technological and scientific communities. Early in his career he demonstrated that technological creativity and innovation are social and intellectual processes.

Edison received his technical apprenticeship in telegraph offices and machine shops in the Midwest and Boston. During his midteens he worked at the telegraph table in a jewelry store in his Michigan hometown. Like his contemporaries, he manipulated the common components of telegraph apparatus and clockwork: ratchet wheels, escapements, adjusting springs, and gearwork. In contrast to clocks, however, telegraph apparatus exploited a new element, the electromagnet. Armed with this new switching and power source, Edison and his contemporaries explored a wide variety of new applications to electrical communications. In the office he often found components of different “generations” of telegraph systems juxtaposed, and he debated the advantages of different systems with colleagues. He also extended his circle of acquaintances to others of the operator “fraternity” in distant telegraph offices. During his late teens in Louisville and Cincinnati, he not only mastered press-wire telegraphy but investigated the creative technical achievements of others. Working at first from standard telegraph manuals and periodicals, he varied the standard designs for relay, repeater, and duplex circuits. After arriving in Boston at age twenty-one, he not only worked as a telegraph operator but also published articles in the nation’s leading telegraph journal. In his off-hours he pursued his own projects at the machine shop of Charles Williams, Jr., an inventors’ womb that also nurtured the embryonic ideas of Moses Farmer and, later, Alexander Graham Bell.

Edison, like other successful American inventors, learned to work in close association with technical and business people. Perhaps his hearing deficiency encouraged him to depend upon others; and perhaps his experience in machine shops taught him to delegate the making of models to expertPage xxxi precision machinists. From the time of his arrival in Boston in 1868, he joined in partnership with others. He obtained financial support from businessmen such as E. Baker Welch and technical aid from colleagues such as Frank Hanaford and George Anders. He developed a mentor relationship with the two successive editors of the Telegrapher, Frank Pope and James Ashley. In 1869 he joined in partnership with them in New York. A year later they were chagrined to find that, after their help and encouragement, he had so quickly collaborated with others in the telegraph industry—for instance, with Marshall Lefferts of the Gold and Stock Telegraph Company. Edison’s relationship with Lefferts fostered his growing financial and legal sophistication. Increasingly he exhibited an entrepreneurial drive, entering into a complex array of agreements and enterprises that would eventually lead him into a series of lawsuits. By 1873 he had attracted the interest of key leaders in the telegraph industry as they grew increasingly sensitive to the significance of invention and technical innovation as a business strategy.

The leaders of the telegraph industry were keenly aware of the needs of their markets and operations. Accordingly, they interacted with Edison and other telegraph inventors, identifying what improvements in telegraphy could reduce costs and might lead to patents that would either deter competitors or serve as a means of entry into a market dominated by others. At first these business leaders set the technical and economic agenda for Edison and other inventors. Increasingly, however, Edison learned the subtleties of the economics of business and developed technical goals and solutions that reflected the influence of the market.

For example, during the early 1870s improvements that would increase message density on a single line were of general interest to the leaders of the American telegraph industry. However, because the leaders of each sector of the industry perceived the critical cost factors differently, they pursued different technical approaches. With a network of lines across the nation, Western Union bore the substantial capital cost of building and maintaining telegraph wires. Thus, in 1872 it enthusiastically adopted Stearns’s duplex system with its potential for capital savings. In turn, Edison renewed his developmental work with duplex, diplex, and other forms of multiple telegraphy. He also worked on automatic telegraphy—another approach to increasing message density and one that was attractive to former Associated Press manager DanielPage xxxii Craig, a Western Union rival. Edison responded to perceptions of the importance of labor costs in the transcription of long press messages and sought to introduce the labor-saving roman-letter automatic telegraph. Indeed, the business and social environment broadly defined the technical problems or agenda and contributed to his solutions; however, the economics of the marketplace did not alone determine the character of his inventions. As indicated below, Edison’s personal style, the traditions of the technical fields within which he worked, and other cultural factors also shaped his inventions.

Another issue that has attracted the attention of popular writers for many years is Edison’s “method.” Traditionally, biographers have described his method as “cut-and-try.” His search for lamp filaments in the early 1880s and his search for a substitute for rubber in the late 1920s epitomized this characterization. Unfortunately, it implied that he did not employ principles or theory but instead “mindlessly” tested every conceivable thing until he found something that would work. A number of the documents in this first volume indicate that such a characterization of Edison’s approach to invention is very misleading.

Edison consistently consulted the technical and scientific literature and let ideas guide his work. Although he did not have formal training in science or mathematics and likely was not conversant with all of the latest physical theories, he kept alert to new developments in electrical science and did operate from technical principles if not from scientific theory. For example, from the early days of his career he employed the polarized relay in various circuit designs, deliberately exploiting its ability to respond to the alternating direction of a current. As early as April 1873 he used concepts of a “balanced line” and a “center of resistance” in a line—a method of dealing with what we today call the resistance, capacitance, and inductance in a line. On the basis of these principles, he offered a number of circuit designs for automatic telegraphy on cables or long land lines. In other contexts he even referred to atoms and waves. Clearly, Edison was not a theoretical scientist, but neither was he a tinkering mechanic, mindlessly stumbling upon workable ideas. The documents of Edison’s early career suggest that he was a highly inquisitive individual who used many sources to acquire information, ideas, and principles pertinent to the topics of his investigations.

Although some of Edison’s early work seems to reflect the cut-and-try method, closer examination reveals a more conceptualPage xxxiii approach, one that could be called “theme and variations.” In his rough sketches in 1867, for example, he took basic designs and made modifications. The laboratory notebooks dealing with both printing and automatic telegraphy in 1871 and 1872 also reflect this approach. Early in 1872 he devoted an entire notebook to drawings of 100 escapement mechanisms, thereby preparing for himself a thesaurus of known ways of controlling motion. When he renewed his work with duplex telegraphy in late 1872 and early 1873, he again sketched a large number of design possibilities that were variations on basic principles. In a similar manner he repeatedly sketched sets of circuits for automatic telegraphy. This approach may reflect in part the influence of the United States patent system. Edison knew well that it was a good strategy to cover all possible approaches to a particular problem in order to gain the broadest claim in a single patent or to obtain many different patents in order to cover a new technical field. This motivation likely reinforced his natural propensity for “technological play”—problem-solving in which, for his own intrinsic satisfaction, he sought all conceivable solutions.

Edison’s telegraph designs reflect the centrality of transmission-reception configurations in the foundations of his creative work. Some scholars have previously emphasized his “systems” or holistic approach to design.³ When Edison focused on a single component of telegraph design, he generally placed such work in the context of the entire circuit. For example, duplex and diplex telegraphy—transmitting and receiving two messages simultaneously over one wire—involved circuits with components that interacted with each other. Design and modification of such circuits required viewing the circuit as a whole. Other telegraph circuits required matching the transmitter with the receiver in the context of the whole circuit. When Daniel Craig first engaged Edison to work on automatic telegraphy, Craig asked him to improve the design of the perforator for Little’s system; Edison, however, soon moved beyond the perforator, conceptualizing the problem as one that involved all the components in automatic transmission and receiving. Indeed, his early experience with telegraph transmitters and receivers likely fostered in him an approach that continued into his later work with the telephone, phonograph, electric light, electric power systems, ore milling, and motion pictures. For example, when Edison later began working on incandescent lighting, he first focused on the lamp but gradually extended his view to the other interacting components,Page xxxiv treating the system’s dynamo as a “transmitter,” the distribution system as the “line,” and the lamp as a “receiver.” As others have noted, he also worked on electric lighting by drawing analogies with gas lighting.

Edison’s notes, sketches, and artifacts also suggest the centrality of visual-spatial thinking to his technical creativity, and they stimulate questions regarding the possible role of tactile, kinesthetic, and quantitative thinking in his designs.⁴ The documents concerned with mechanical and electromechanical designs, such as those in printing and automatic telegraphy, constitute the first record of his visual conceptualizations. At times, his mechanical constructs remind us of the contraptions in Rube Goldberg cartoons, but with the important difference that Edison ultimately sought to avoid mechanical awkwardness and to make his many inventions commercially practicable. Although his sketches do not represent machines in perfect three-dimensional, orthogonal, fixed-point perspective, they do indicate that he effectively conceived of mechanical operations in three dimensions. The early record of his visual thinking contained in the drawings and artifacts in this volume also suggests that he developed a repertoire of stock solutions and visual forms from his telegraph experience. He repeatedly included the dual solenoid, the ratchet wheel escapement, the rotating drum and stylus, flowing tape and stylus, and the polarized relay as central components in his creative designs. Sometimes these forms dominated the composition of his designs, suggesting that analogy played an important role in his creative thinking.

These “methods” marked Edison’s inventive style. He remained concerned with communications technologies during most of the 1870s, returned to them in the middle 1880s, and continued working on them into the twentieth century, pursuing new designs for the telephone, railway telegraphy, the improved phonograph, and motion pictures. The cylinder-stylus form evident in his facsimile telegraph designs of 1868, for example, recurred in automatic telegraphy in the early 1870s, in the electromotograph in the mid-1870s, in the original phonograph in 1877, and in his earliest conception of the motion picture in 1888. Before filing his first patent application for the phonograph, he sketched on a single sheet of paper three different versions of the instrument: cylinder, disc, and tape. His first motion picture drawing in October 1888 was based by analogy on the cylinder and stylus form of his cylinder phonograph and also included the ratchet wheel andPage xxxv solenoids. Later, he added a polarized relay and moved to flowing tape (film), complete with perforations to keep it in register. The latter, as he noted at the time, was analogous to the Wheatstone automatic telegraph. These examples suggest that Edison’s early work in telegraphy provided direction and intellectual resources for his subsequent career.

The variety of technical fields within which Edison worked during his lifetime is extraordinary. This diversity even characterized his early telegraphic pursuits. He did not confine himself to one area of telegraphy, such as printing, automatic, or multiple telegraphy, but instead worked across the field, frequently on different areas at the same time. His early documents suggest cross-fertilization of ideas and techniques among the different areas of telegraphy. For example, he employed multiple signaling techniques, including use of the polarized relay, in both printing and multiple telegraphy. Another example is his introduction of condensers for automatic telegraphy for long land lines in 1873. This use of condensers may have derived from his awareness of Stearns’s successful 1872 introduction of condensers in duplex circuits. Besides the potential for cross-fertilization of ideas among fields, Edison’s diverse work, including business as well as technical design and production, likely prevented him from focusing on just one problem and acquiring a mind-set.

Edison’s early experience in business also shaped his later career. In the telegraph industry he worked increasingly with captains of industry, gaining an enviable reputation as a telegraph inventor. His invention of the phonograph in 1877 attracted world-wide acclaim and simply reinforced the high regard the leaders of the telegraph industry had for his creative abilities. Consequently, when he began work on electric lighting in 1878, his old financial friends from the telegraph industry introduced him to their friends in the railroad and banking communities and helped him acquire financial support for his efforts in fields beyond telegraphy.

Edison’s early pattern of working with others in the technical world also continued into his later career and became largely institutionalized. In his early shops in Newark, he established experimental facilities where small teams of men assisted him with instrument manufacture and inventive design. This network of manufacturing facilities provided the human, technical, and material resources for his creative work and was the embryo of his later separate laboratories in Newark, Menlo Park, and West Orange.

Page xxxviThe documents in this volume are, to borrow a phrase from his close associate Francis Upton, “a record of how inventions are made.” Indeed, the reader can see the earliest evidence of Edison’s thinking, his false starts, and the subsequent steps and stages in the creative process. Moreover, the documents reveal Edison’s collaboration with his associates, his complex legal and financial affairs, and his dependence upon the persons and publications of the larger technical communities of telegraph inventors and scientists. They also hint that there were many other creative people who worked on similar problems and often were more successful than Edison with specific inventions. These rivals of Edison in the race to the patent office have too often disappeared from history because of scholarly neglect and the long shadow of the diverse, prolific, and highly visible Edison. Divorced from its context, Edison’s work has traditionally been regarded as wondrous or miraculous. When embedded in its historical setting, his overall achievement remains remarkable but eligible for rational understanding.

Some of Edison’s laboratory notebook entries and business documents may appear complicated, detailed, and even forbidding, but, like his letters to Frank Hanaford or those from Daniel Craig, they too reflect his exuberant personality and multifaceted daily life. They unveil the very human inventor and deliberate entrepreneur. Like the America from which he came, he was rough-hewn, energetic, and aggressive. As we enter into his world through his notebooks, we find him exclaiming, “oh god”; “Invented for myself exclusively, and not for any small brained capitalist”; and “My Wife Popsy-Wopsy Can’t Invent.” In the process, we discover the real Thomas Edison: the exceptional technical thinker, the shrewd if not always successful entrepreneurial strategist, and the man, with all his enthusiasm, persistence, overconfidence, and “warts.”