"For a considerable portion of the present century, Davy's discoveries about heat were neglected, or only casually mentioned; but this was of comparatively little consequence, as their early reception might have kept back for a time the grand developments which must next be mentioned—immense strides in the theoretical and mathematical treatment of the subject, and to a considerable extent independent of the nature of heat. These are due to Fourier and Sadi Carnot, and it may well be said that it is in great part attributable to their remarkable works that the true theory of heat... received so rapidly its present enormous development. ...Very different in form and object from the systematic treatise of Fourier, is the profound and valuable essay of Sadi Carnot, Reflexions sur la Puissance Motrice du Feu, published in 1824. The author endeavours to determine how it is that heat produces mechanical effect..."