Essais des Metaux, Theorie et Pratique

Abstract

THIS little work, the sixth of the “Aide-Memoire” series on metals, by the same author, is written with much of the charming clearness of diction generally found in French metallurgical writings. There are two parts, the first on the theory of the tests and the second on practice. Considering the size of the page (convenient for the pocket), the matter is wonderfully well treated. Thus, to take the tensile test as an example, there is a general heading, Preliminary Ideas, with paragraphs (1) Period called Elastic, (2) Period of Deformation, (3) Contraction, (4) Curve of Traction. In this last is worked out from the ordinary tensile curve, showing elongation and tons per square inch on the original section, a curve showing tons per square inch on the real section, thus making plain to the student the reason for the apparently paradoxical form of the ordinary curve. The next main heading is the Law of Similitude, treated under six subheadings, the first of which, for example, considers the two permanent elongations produced during tensile testing. These two very distinct elongations are not only made clear, but methods are given for their determination, and the steps in the reasoning are worked out by simple mathematical methods where necessary. In like manner are handled such subjects as elasticity, influence of temperature, repetition of stresses, distribution of deformations, augmentation of elastic limit. Essais des Metaux, Theorie et Pratique. By L. Gages, Chef d'escadron d'Artillerie. Pp. 168. (Paris: Gauthier-Villars, no date.) Price 3 francs.