THIS small pamphlet describes clearly and simply certain applications of Carnot's principle to physical problems. The unique feature of the book is indicated in the title. The word “assise” groups together certain variables which refer to distinct physical quantities, but which enter into the equations of energy in the same manner. The only equivalent English word we can suggest is the word “fundamental.” The solution of many types of problem may then be said to depend on the two principles of the conservation of the fundamental and the conservation of energy. The differential of energy depends in general on a product of the form xdy, the precise meaning of x and dy depending on the kind of problem under contemplation, electrical, thermal, elastic, mechanical, or chemical, as the case may be. In these several cases the “assise,” symbolised above by dy, is respectively electric quantity,. entropy, volume, length, and mass. Such quantities all obey the conservation law, which the author concisely defines in these words:—Under the action of physical and chemical phenomena there can be no creation of electricity, of space (linear or cubical), of entropy, or of matter. Four applications are given in which the principle of the Carnot cycle is ingeniously utilised. The novel use of the word “assise” seems to be the main feature of the pamphlet; otherwise there is not much which calls for special remark.
Le Principe de la Conservation de l'Assise et ses Applications.
By George Matisse. Pp. 65. (Paris: Libraire scientifique, A. Hermann, 1907.) Price 2.50 francs.