Correspondence Structural Steelwork

The CHAIRMAN (Mr. Ewart S. Andrews, Vice-President) proposed a very hearty vote of thanks to Dr. Faber for his delightful and valuable paper.

(g) Influence diagram for the force in member V The kinematic chain resulting from the removal of V4, is shown in Fig. 32. Assume rib V to be fixed and let 8-8’ represent the perpendicular velocity of 8, 8’ being the intersection of 9-8 with the line of the bottom chord. H.A. Whitaker

DURING the last decade or so experience has shown that, apart from the action of frost and temperature variations, concrete and other masonry structures subject to unilateral water pressure are also liable to deterioration due to the action of percolating water. This has been experienced specially with dams in countries with primary rock, such as Scandinavia, Finland and certain parts of France and Switzerland, as well as in U.S.A., and the reason seems to be that the river waters in countries of such a geological nature generally do not contain lime, and that they are acid in reaction. Leaky and defective old dams, however, also exist in other parts of the world. B. Hellstrom