Reinforced Concrete Beams Subjected to a Sustained Torque

An article by Gerda Cohen in a recent issue of New Statesman discusses the effects on the environment of today's insatiable demand for aggregates; in particular the gigantic encroachment on the limestone areas to meet the demands of the steel and glass industries and for road construction. Her solution for the last is to substitute the vast quantities of spoil in the tips 'which deface South Wales and the Midlands'. Miss Cohen thinks that 'because civil engineers have always shown reluctance in exploiting unorthodox material, the Verney Committee has encouraged research into the potential of colliery waste'. Verulam

Lt.-Col. N. D. Clifford, MBE, RE: As a mere military engineer I shudder at the thought of trying to make any technical points in front of such an august audience. I would, however, like to make one or two philosophical points.

Having recently carried out two years' research in a similar field, I read the above report with interest, and would like to make the following comments. R.E. Brand