Published by EH.NET (February 2010)

Ross Thomson, Structures of Change in the Mechanical Age: Technological Innovation in the United States, 1790-1865. Baltimore: Johns Hopkins University Press, 2009. xiv + 432 pp. $68 (hardcover), ISBN: 978-0-8018-9141-0.

Reviewed for EH.NET by Lisa D. Cook, Department of Economics, Michigan State University.

The author cleaned the Augean stables of historical data related to invention to bring the reader a rich and detailed study of the early development of the American system of technological innovation. The volume starts with a vivid juxtaposition of the antebellum and postbellum economic and inventive environments. Path-breaking inventors in the mid- to late nineteenth century, like Thomas Edison, Joseph R. Brown, and George Corliss, had the advantage of a pre-existing innovation system resting upon the pillars of ideas, markets, institutions, and skilled labor. In the earlier period output was rising because small-scale production was increasing in scale. Yet, technological progress occurred more slowly, because there was no change in techniques. Among the initial conditions were several factors constraining development and adoption of mechanization, including small markets, scarce human and financial capital, and limited technological knowledge. Thomson argues that the innovation system that developed as a result of actions from above ? government ? and below ? among self-interested innovators ? was integral to the success of the American Industrial Revolution.

In Thomson?s view, this new system of firms, individuals, and markets had two critical components. First, knowledge had to be gained and developed. Scientific investigation had to be undertaken (or taken from Britain) and applied. Second, it had to be disseminated and developed further to augment future technological development. He emphasizes important feedback effects throughout the process of innovation and building innovative capacity. Embodied technological progress appeared in machines, which were related or unrelated to a given invention. General purpose technologies were critical for cross-fertilization. Embodied technological progress also appeared in machinists and inventors.

The new innovation system was characterized by two seemingly opposing but intricately intertwined features: structure and change. Structures, like the patent system and scientific institutions, are the midwives that bring to fruition new ideas and technological change. To explain the evolution of structure and change, he organizes chapters chronologically and then thematically.

The significant contributions of this book derive from three sources: the amount and type of data collected and examined, the extension of previous work on major innovators, and the exposition of the relevance of social interactions in innovative systems.

Thomson carefully presents systematic evidence on the emerging innovation system in the mid-1800?s, using data on innovators, firms, industries, patents, and various technologies. One thousand individual innovators and 14 industries are covered in 50 data sets and other primary and secondary sources. The focus of the volume is patented invention. However, like Moser (2005) and a number of subsequent studies, he extends the examination to include exhibits at industrial fairs, including the New York Crystal Palace Exhibition and the New York World?s Fair in 1853 and other unpatented inventions. As a result the data,, and the book more generally, constitute a rich resource for research on innovation during this period.

The research presented on major innovators extends the work of Ciarlante (1978) and Khan and Sokoloff (1993). While he starts from the Dictionary of American Biography (1937) to identify major innovators as do Ciarlante and Khan and Sokoloff, he broadens the scope of investigation by adding those who may not have been as well known or socially connected as those in the DAB, e.g., from the Biographical Dictionary of Civil Engineers (1972 and 1991). To demonstrate how learning and dissemination evolved in this innovation system, he provides detailed summaries of data on location, occupation, specialization, educational attainment, and patent usage and commercialization.

Thomson argues persuasively that interactions beyond formal institutions were as important for development of the American system of innovation as those within them. Institutions ? firms, markets, occupations, patenting systems, publications, schools, and civil organizations ? often created asymmetries in knowledge and in its dissemination, and individuals through networks served as a corrective mechanism. He offers science as an illustration of the balance between institutions and individual networks, given its dual focus on institutions and policies and on individuals with respect to integrating science into economic life.

Further, he asserts that technological centers, large groups that played a significant role in processes of invention, diffusion, and development and fostering growth and innovation broadly across the economy, were the locus of networked innovative activity. In particular, he places machinists and the machinery industry and science and the institutions of transmission of scientific output at the epicenter of this innovation system. Using data from the Manufacturing Manuscripts of the Census and the Patent Office, he exposes mobility and linkages across industries and demonstrates that machinists were such industry-spanning technological centers.

One might have three minor quibbles about this volume. First, while the clear intent is to reinforce and provide further support for his thesis, the book is repetitive in places. For those who will use it as a reference and individual chapters by themselves, this feature may be inconsequential, and each chapter being self-contained may be an advantage.

Second, some counterfactual analysis appears in the volume. Nonetheless, more of such analysis would have been helpful to the reader. For example, in Chapter 8, Thomson argues that without distinct knowledge bases, the U.S. ?might well have succeeded in some innovations and failed in others. Without science the United States could have developed the sewing machine but not the telegraph …? (p. 257). Such statements require further probing. International comparisons, particularly to England, are deployed effectively in other places and are desirable here and elsewhere in the book. Are there places where varying innovations emerged in the absence of innovators? access to many kinds of knowledge? The reader clearly gets the sense that America?s system of innovation was exceptional but is not entirely sure why.

Finally, I believe Thomson misses an opportunity to provide a vivid example of his thesis by repeating the conventional wisdom related to Eli Whitney. A reference to his negative experience with his cotton gin and the patent system is briefly invoked early in the book (pp. 19-20). Lakwete?s (2003) careful research challenges the received wisdom about Whitney and shows that southern machinists and farmers quickly tested and improved his version of the cotton gin. Before Whitney?s patent expired, southern farmers developed incremental improvements and adopted a new gin with circular saw teeth rather than Whitney?s wire teeth, the source of novelty but less of usefulness. This more complete story would have provided clear support for Thomson?s innovative-feedback thesis while acknowledging imperfections in the patent system and its enforcement.

These quibbles notwithstanding, this book accomplishes a Herculean task of data collection and analysis. The antebellum period has been understudied, allowing scholarship on later periods to take the foundations of the innovation system for granted. It is an important work and likely to become required reading for generations of scholars of the innovative process.


Biographical Dictionary of Civil Engineers, 2 volumes. New York: American Society of Civil Engineers, 1972 and 1991.

Ciarlante, Marjorie Heins. A Statistical Profile of Eminent American Inventors, 1700–1860: Social Origins and Role. Ph.D. Dissertation, Northwestern University, 1978.

Drake, Francis S., editor. Dictionary of American Biography. Boston: Houghton, Osgood, 1879.

Johnson, Allen and Dumas Malone, editors. Dictionary of American Biography, 21 volumes. New York: Charles Scribner?s Sons, 1937.

Khan, B. Zorina and Kenneth Sokoloff. ??Schemes of Practical Utility?: Entrepreneurship and Innovation among ?Great Inventors? in the United States, 1790-1865,? Journal of Economic History, 53 (2) June 1993: 289-307.

Lakwete, Angela. Inventing the Cotton Gin: Machine and Myth in Antebellum America. Baltimore: Johns Hopkins University Press, 2003.

Moser, Petra. ?How Do Patent Laws Influence Innovation? Evidence from Nineteenth-Century World’s Fairs,? American Economic Review, 95(4) Sept. 2005: 1214-36.

Lisa D. Cook is an assistant professor in the Department of Economics and James Madison College at Michigan State University. Her research focuses on the economics of innovation and economic growth and development. The subject of a recent article (in the American Economic Review: Papers and Proceedings 2009) is Africa?s growth experience in recent economic history.