THE development and application of pre-stressed concrete have been discussed in a series of comprehensive papers by Mr. T. J. Gueritte, (l,2) while the principles of pre-stressing are now being extensively practised in Europe and America. Elaborate experiments have been carried out on the Continent concerning the elimination of tension in concrete by Dr. K. W. Mautner. (5) Few experiments, however, have been made in this country to-investigate the question of shear or diagonal tension in pre-stressed concrete beams, although a horizontal precompressive stress has a component opposing the diagonal tensile stress due to shear. For example, consider the state of stress at the neutral axis of a beam. R.H. Evans and G. Wilson
THE design of the fixed arch involves labour generally out of all proportion to the size of the bridge, utilizing the elastic theory which while producing sufficient accuracy does not lend itself to easy and expeditious solution. L.E. Hunter