Reflexions on the Motive Power of Fire: A Critical Edition with the Surviving Manuscripts by Sadi Carnot

Abstract

144 Book Reviews TECHNOLOGY AND CULTURE This edition is serviceable. The introductions are brief and clear, the first of the four short articles perhaps slightly limp, but the others—on the architecture, the technology, and the drawings—are admirable. The (newly photographed?) plates are in some cases blurred, sometimes (plate 20) even out of focus. But this is a paper­ back to be bought and studied with endless fascination. Jacques Heyman Dr. Heyman is head of the Department of Engineering at Cambridge University. Reflexions on the Motive Power of Fire: A Critical Edition with the Surviv­ ing Manuscripts. By Sadi Carnot. Edited and translated by Robert Fox. Manchester and New York: Manchester University Press and Lilian Barber Press, 1986. Pp. ix + 230; notes, appendixes, bibliog­ raphy, index. $39.50. In 1814, Sadi Carnot joined with other students at the Ecole polytechnique in a last-ditch attempt to defend Napoleon’s Paris from the advancing armies of Great Britain and her allies. A dec­ ade later, he joined in the French response to another British ad­ vance, improved power technology. In a small book entitled Reflexions on the Motive Power of Fire, Carnot discussed in general terms the operation of heat engines. He argued that the maximum possible efficiency of an engine operating between any two tempera­ tures depended only on the temperatures at which heat was sup­ plied and removed. This maximum efficiency was the same whether the working substance of the engine was steam, air, or even a solid. Here Carnot assumed that heat, or, as he put it, calo­ ric, was conserved in the operation of an engine and not trans­ formed into work. Carnot’s Reflexions had no greater immediate effect than had his soldiering. Carnot himself soon abandoned the fundamental assump­ tion that heat cannot be converted into work. Contemporary physi­ cists and engineers largely ignored his book, and Carnot died in obscurity in 1832. At mid-century, however, the British physicist Wil­ liam Thomson drew new attention to Carnot’s work, making its ap­ proach a central part of the emerging science of thermodynamics. Over the past quarter-century, distinguished historians have exam­ ined the context, content, and reception of Carnot’s work. Robert Fox prepared a critical edition of the Reflexions in 1978 and has now completed a new English translation. His graceful introduction de­ scribes problems of steam engineering that concerned Frenchmen of the 1820s, outlines Carnot’s life, suggests connections between his approach to steam engines and his father’s work in mechanics, and discusses the reception of the book. The text follows, with a valu­ able commentary that reveals Fox’s careful examination of Carnot’s manuscripts, his wide knowledge of contemporary French physics TECHNOLOGY AND CULTURE Book Reviews 145 and engineering, and his assiduous attention to the work of other his­ torians. Appendixes give translations of a manuscript paper of Car­ not and of notes in which he recorded his doubts about the conservation of caloric. Here Fox again provides commentary, as well as a general discussion of surviving Carnot manuscripts. He con­ cludes with a useful bibliography and index. Fox’s translation not only makes the Reflexions accessible to the mod­ ern reader but places Carnot’s theory of heat solidly in the context of contemporary steam engineering. It will intrigue those who seek to understand historically the interconnections of science and tech­ nology. Peggy Kidwell Dr. Kidwell has written about 19th-century theories of heat as they were applied in astrophysics. She currently watches over objects in the Division of Physical Sci­ ences and Mathematics, National Museum of American History. The History of Civil Engineering since 1600: An Annotated Bibliography. By Darwin H. Stapleton with Roger L. Shumaker. New York: Gar­ land, 1986. Pp. xxxiii+232; index. $40.00. Since the appearance of Eugene Ferguson’s Bibliography of the His­ tory of Technology twenty years ago, both the volume of literature and the number of researchers in the field have grown enormously. There is consequently a real need for updated and more special­ ized bibliographies such as the present work by Darwin Stapleton on the history of civil engineering since 1600. Stapleton’s bibliogra­ phy is divided chronologically...