Anyone delving into the past history of concrete cannot fail to be impressed by the astonishing amount of knowledge possessed by ancient engineers. It would seem that the only difference between them and their modern counterparts is that they did not have slide rules and computers. They certainly had a great deal of courage, ingenuity and engineering ability, and produced some astounding structures. J.E.C. Farebrother
Sir, Whilst I have a high regard for Mr. Creasy and as usual thoroughly enjoyed his paper on the above subject, I would likc to correct him on his reference to the submission of structural designs for Local Authority approval.
As buildings in Hong Kong have increased in height without necessarily increasing in width, so the effect of " Typhoon " wind pressures on structural design has become increasingly important. Many buildings are now stiffened against the effects of wind by in-situ concrete shear walls, which, as vertical cantilevers, normally follow the requirements of CP 114-1957 in respect of height width ratios in an effort to limit horizontal deflexions. Buildings witheight width ratios of less than 2 which were designed without wind prior to 1958 (which year saw the introduction of the requirement that all buildings in Hong Kong should be designed against the effect of wind, irrespective of height width ratio), have in a recent typhoon exhibited the tendency to vibrate to an uncomfortable degree, with however no signs of structural failure. A shear wall stiffened building has on the other hand been reported to be almost free from vibration at the height of the typhoon. K. T. Philcox
Long span bridges are defined as those in which the influence of deadweight and construction methods becomes of the greatest importance, and for the purpose of this paper will include bridges having spans of 150 ft. or more. E.W.H. Gifford
The Institution welcomes as its President for the Session 1962-63 Mr. E.N. Underwood, BSc. (Eng.), M.I.Struct.E., M.I.C.E., who takes office on the 4th October.