ABSTRACT
The most thorough attempts to trace the diffusion of the steam engine in the eighteenth century have traced 2191 engines (8.7). The casual evidence of contemporaries on the number of engines in specified areas suggests a possible total of 2400 to 2500 engines built in the eighteenth century (Kanefsky and Robey, 1980). This upward revision of previous counts follows a long tradition, but it should be noted that there are probably some upward as well as downward biases in these data. Twenty-seven of the engines were ‘experimental’, i.e. not applied to industrial purposes. The figures relate to the number actually standing in 1800, but it is difficult to eliminate the double counting of engines moved from one site to another. Kanefsky and Robey counted 478 Boulton & Watt engines erected in Great Britain, which Jennifer Tann’s recent and definitive count reduced to 451 (1981). Most of the engines for which Kanefsky and Robey have not been able to prepare computer cards were probably small, e.g. winding engines on the Staffordshire coalfield.
