Structures-The Impact of Modern Metallurgy Discussion on the Paper by Professor A. G. Quarrell, D.Sc

THIS paper deals with a class of arch known as the “Stabbogen.” The arch is loaded through the hangers which may be referred to as “wire-hangers” since they are assumed to be simple tension members having comparatively small flexural rigidity. The hangers are connected to a rigid chord at their lower ends, and thus become inclined when the arch rib deflects laterally. The load is considered to be applied by means of a horizontal thrust H at the ends of the rib instead of through the hangers. Chin Fung Kee

The two extremes of pressure to which a retaining (i) the active pressure of the soil on the back of a wall resulting from slight movement of the wall away from the filling, and (ii) the passive resistance of the soil on the front of a wall to slight displacement of the wall towards filling. J. Rygol

This month's letters include additional references for the June issue's Regent Street disease article and discussions about seismic design and minimum qualifications for carrying out structural engineering services.