Patent Office Records as a Historical Source: The Case of Thomas Edison

Field: Arts and Humanities (Social Sciences)

Research Note PATENT OFFICE RECORDS AS A HISTORICAL SOURCE: THE CASE OF THOMAS EDISON PAUL ISRAEL AND ROBERT ROSENBERG Thirty-one years ago in this journal Nathan Reingold surveyed U.S. Patent Office records.1 Reingold described National Archives Record Group 241 (RG-241) in detail, pointing out the rich sources for studies of technology, invention, and business. Since that time historians have begun making greater use of the full range of patent records, particularly in several studies of individual inventors.2 Over the past ten years, in pursuing the career of America’s most prolific Patent Office client (1,093 U.S. patents), we and our colleagues at the Thomas A. Edison Papers have acquired an intimate familiarity with RG-241. More important, the depth of the Edison archive in West Orange, New Jersey, has given us a rare opportunity to assess comDr . Israel and Dr Rosenberg are editors of the Thomas A. Edison Papers at Rutgers University, New Brunswick. They would like to thank George Basalla for suggesting this research note. ‘Nathan Reingold, “U.S. Patent Office Records as Sources for the History of Invention and Technological Property,” Technology and Culture 1 (1960): 156-67. 2Studies of individual inventors include W. Bernard Carlson, “Invention, Science, and Business: The Professional Career of Elihu Thomson, 1870—1900” (Ph.D. diss., University of Pennsylvania, 1984); Carolyn C. Cooper, Shaping Invention: Thomas Blanchard’s Machinery and Patent Management in Nineteenth-Century America (New York, 1991); and Thomas P. Hughes, Elmer Sperry, Inventor and Engineer (Baltimore, 1971). For industrial studies using Patent Office records see Paul B. Israel, From the Machine Shop to the Industrial Laboratory: Telegraphy and the Changing Context ofAmerican Invention, 1830-1920 (Baltimore, forthcoming); and Steven Lubar, “Corporate and Urban Contexts of Textile Technology in Nineteenth-Century Lowell, Massachusetts: A Study of the Social Nature of Technological Knowledge” (Ph.D. diss., University of Chicago, 1983). Economist Ross Thomson’s recent study of invention in the shoemaking industry, The Path to Mechanized Shoe Production in the United States (Chapel Hill, N.C., 1989), traces inventive activity beyond that discipline’s traditional reliance on patent statistics, issued patents, and the Annual Reports of the Commissioner ofPatents, in that he investigates inventors’ occupations, business relations, and geographical location. However, his use of Patent Office records is limited to the printed patent specifications.© 1991 by the Society for the History of Technology. All rights reserved. 0040-165X/91/3204-0004$0 LOO 1094 Patent Office Records as a Historical Source 1095 paratively the historical utility of the various post—Civil War Patent Office records. Patents are often described as a record of invention, and in a certain sense they are. But because patents are primarily legal devices, the relationship between patents and the inventions they are supposed to describe is limited in important ways. Frequently, little of the activity leading to commercial practicability is revealed in the issued patent specification, and the information provided by ancillary Patent Office records—application, amendments, interferences—is often mislead­ ing without recourse to the kind of archival resources Edison left behind. Indeed, the issued patent may not even describe the inven­ tion as it actually existed and was used, because exigencies of production and accommodations to the end users of an invention often resulted in modifications not included in the patent. As Nathan Rosenberg has forcefully pointed out, the greatest eco­ nomic value of a major technological innovation usually accrues through incremental improvements, rather than immediately from its initial introduction.3 Analogously, we see Edison patenting an idea and then having to refine it in many small, nonpatented ways to make or keep it competitive in the marketplace. Most often, when we compare an invention in its practical form to the patent protecting it, we find differences ofvarying degrees ofsignificance. These are almost always small engineering changes that make the existing device work better, not new ways of achieving the same thing, and as such are unpatent­ able. Nevertheless, they are essential to the success ofthe invention. On one printing telegraph, for example, Edison moved a device used to start a small motor; on another, he moved an electromagnet; he worked on the mechanism of the large perforator...