Presidential Address

A study is made of the design, by the method of plastic collapse, of pitched roof portal frames incorporating members of variable section. On the basis of the simple plastic theory conclusions are reached as to the material economy available with the use of pinned and fixed base frames of variable section, In the latter section of the paper the collapse behaviour of frames with tapered members is discussed in detail and attention is drawn to the differences in behaviour between the frame of uniform and the frame of variable section, differences which are not apparent on the basis of the simple plastic theory. B. J. Vickery

THE PRESIDENT said the subject of the paper was extremely interesting and it was valuable that the members of the Institution should have the opportunity to learn about it.

THE PRESIDENT, in thanking Professor Sattler for a most stimulating lecture, said the meeting would wish to offer their very great appreciation of it and their congratulations on his reading of the English language.