Some aspects of the determination of the strength of materials formed the subject of two meetings held jointly with the British Rheologists’ Club (President, Prof. E. N. da C. Andrade) and the Royal Aircraft Establishment in the Assembly Hall, Farnborough, on the 16th June, 1945, and with the Royal Aeronautical Society in the library at 4, Hamilton Place, on the 19th February, 1946, under the chairmanship of Sir Ben Lockspeiser.

At the Farnborough meeting three papers were read, namely, “The investigation of failures in wood by microscopical examination” by M. C. Pryor and A. Rayne; “The effect of duration of loading on the strength of brittle materials” by C. Gurney; and “Application of statistical methods to mechanical test results” by B. Chalmers and E. R. W. Jones. At the London meeting Prof. N. F. Mott of Bristol University spoke on the “Griffith theory of cracks in solids and recent developments of this theory, with application to brittle fracture in glass and in metals.”