A considerable amount of attention has been devoted to the study of the position of the centre of shear for straight beams but there appears to have been Uttle or no consideration of this position for beams of which the centre line is either shghtly or heavily curved. The reasons are probably twofold. Firstly, no demand for such an investigation has been made by designers, and secondly, and probably not least, any very general inquiry into this problem will lead to complex expressions which would not only be difhult and tedious to evaluate but will also be of uncertain accuracy.

This problem of taking beam curvature into account starts from the point where it normally ends for most mechanical engineers, who usually require to estimate the bending stresses in members of large curvature such as hooks and chain-links. Now the classical theory of elasticity applied to these latter members has yet to be seen to conform with experimental results to such a high degree as makes the added labour attending such methods worth while.