Since I consider the story to be presented here as being well suited as an introduction to the prehistory of thermodynamics, I have chosen to explain the basic ideas of Carnot's theory in slightly more detail than is customary.

I want to thank Ole Knudsen for many useful discussions, Robert Fox and Keith Hutchison for very valuable criticism and Jacques Chevallier for aid with the transcriptions. I am grateful to M. Bouniol from Conservatoire National des Arts et Métiers, Paris and Mme. Jacques, Ecole Nationale Supérieure des Beaux-Arts, Paris, for allowing me to publish the manuscripts.

¹ Throughout this paper, I shall refer to the annotated edition: Sadi, Carnot: Réflexions sur la puissance motrice du feu, édition critique par Fox, Robert (Paris 1978)Google Scholar, where the original pagination appears in [ ]. This edition also contains transcriptions of all the significant Carnot manuscripts that have survived.

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³⁷ This will be explained in my forthcoming book on Sadi Carnot and the birth of thermodynamics.

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