Abstract
in the previous report the authors had introduced the method, which determines the algebraic sum of the principal stresses in metals by X-rays. But, as it was not sufficient with this method, here has been' demonstrated the more important method, which determines the component of the internal stress in any direction, and moreover the directions of the principal stresses and their quantities, by means of projecting the X-ray beams rectangular and oblique to the surface of materials respectively; and it is remarkable, that it needs not to know the normal lattice constant in the stressfree state, by using this method. According to the results of the experiments by the authors, various steels have had different lattice constants, therefore it has been recognised that the latter method is necessary, when the X-ray method is applied for the practical testing. The authors had also investigated the relation between the tensile stress and the lattice spacing about mild steel, and obtained some desirable results.
