The Diffusion of Newcomen Engines , 1706 - 73 :

The present paper attempts to quantify the diffusion of Newcomen engines in the British economy prior to the commercial application of the first Watt engine. It begins by pointing out omissions and discrepancies between the original Kanefsky database and the secondary literature leading to a number of revisions of the former. The diffusion path is subsequently drawn in terms of adopted horsepower and adjusted for the proportion of the latter being in use throughout the period. This methodology differs from previous studies which quantify diffusion based on the number of steam engines and do not take into account those falling out of use. The results are presented in terms of aggregate, sectoral, and regional patterns of diffusion. Finally, following a long held methodology of the literature on technological diffusion, the paper weighs the number of engines installed by the end of the period in relation to the potential range of adopters. In the end, this method generates a less celebratory assessment regarding the pace of diffusion of Newcomen engines. *The author wishes to thank Alessandro Nuvolari for providing access to the Kanefsky database. Two summer fellowships from the NEH/Folger Institute and Dibner Library (Smithsonian), whose staff was exceptionally helpful (especially Bill Baxter and Ron Brashear), allowed me to draw heavily material from the collection of rare books of the latter. Two graduate students, Lawrence Costa and Michel Dilmanian, proved to be superb research assistants by handling the revisions made by the author to the database, coming up with the graphs, and running the tests involved in the third appendix of the paper as well as writing it. I am also grateful to several colleagues (John Lazarev, Bruce McNevin, Konrad Menzel, and Quang Vuong) as well as three anonymous referees for providing advice that led to substantive revisions. The usual disclaimer applies.