The Effects of Creep on Instability and Indeterminacy Investigated by Plastic Models. Discussion on

Common opinion on the strength of materials'appears to be satisfied that the conventional basis of the mathematical theory of elasticity is fundamentally sound, but needs a little adjustment to allow for plastic yield. The opinion is expressed that this basis is erroneous and should be discarded for the purposes of research on steel in tension. A.C. Vivian

This month's letters include discussion over design checks and suitably experienced engineers as well as seismic design of masonry and more.

The tragedy of the Francis Scott Key Bridge highlights the need for structural engineers to ensure that the risks inherent in our built infrastructure remain acceptable, argues Colin Caprani.