This book discusses problems which arise in elasticity theory and which are not always dealt with satisfactorily in standard texts. Examples are the problem of shear centre for thin-walled sections, and the allied problem of torsion. Similarly, Saint-Venant's principle is often quoted, but is often not precisely understood. The functions of diaphragms in box-beams repays attention by the civil as well as by the aeronautical engineer. This book discusses a few of these less straightforward pieces of structural analysis in a simple and straightforward way. At the same time, it gives an account of the basic variables in stress analysis, of stress and strain, of elastic constants and of the elastic limit, and of equilibrium and compatibility, and will serve as a source book for the fundamental equations of elasticity.