The 899th Lecture to be given before the Royal Aeronautical Society was held on 11th February 1954 at the Institution of Mechanical Engineers, Storey's Gate, London, S.W.I. Mr. G. R. Edwards, C.B.E., F.R.Ae.S., Vice-President of the Society, presided. Introducing the Lecturer, Dr. D. Williams, M.I.Mech.E., F.R.Ae.S., Mr. Edwards said that Dr. Williams was really too well known to need any introduction; his activities had been devoted in recent years to structural problems as applied to aeroplanes. Without reciting his attainments in detail, the job he had tackled in recent years at the Royal Aircraft Establishment and about which he had written papers, covered such subjects as vibration, wing flutter, sandwich construction, the effect of blast on aeroplanes, energy theorems, fatigue, dynamic loading by gusts and landing impacts, water-borne runways and nose-wheel shimmy, a variety of subjects one or all of which had caused most of them a great deal of anguish at one time or another.