The 996th Lecture to be given before the Society and the 26th Main Lecture to be held at a Branch of the Society, was also the First Sir Henry Royce Memorial Lecture inaugurated by the Derby Branch. The Lecture, “ Sir Henry Royce, Bart,” was given by Mr. Ivan Evernden, M.B.E., B.Sc.(Lond.), M.I.Mech.E., M.S.A.E., M.S.I.A., on 1st October 1956 at Derby. Mr. A. A. Rubbra, F.R.Ae.S., Chairman of the Derby Branch opened the Meeting and Dr. E. S. Moult, B.Sc.(Eng.), F.R.Ae.S., Vice-President of the Society, presided for the rest of the meeting.

The 991st Lecture to be given before the Society, “ High Speed Test Flying ” by Lt.-Colonel Charles E. Yeager, U.S.A.F., was given at the Institution of Civil Engineers, Great George Street, London, S.W.I, on 19th April 1956. Mr. N. E. Rowe, C.B.E., B.Sc, F.I.A.S., F.R.Ae.S., President of the Society, presided for the first part of the meeting and Sir Sydney Camm, C.B.E., F.R.Ae.S., Past President, for the second part.

Opening the meeting Mr. Rowe regretted that he was unable to stay for the Discussion but he had particularly wanted to hear Colonel Yeager who was a world figure in the subject on which he was going to address them. This was the concluding lecture of the normal session this year (apart from the Wilbur Wright Lecture) and he felt that they could not possibly have anything better than the occasion which they were going to enjoy that evening.

The lecturer had had a very full life although he was still young and he would touch on a few of the high spots.

Colonel Yeager joined the Army Air Corps as a private and became an aircraft mechanic— so he knew something about the works before he went into the office—and he received his commission as a Second Lieutenant in 1942. He had a distinguished War career and he finished as a group leader. He was an escapist—he was shot down on his twelfth mission, smuggled by the French Underground into Spain, was put into prison; they forgot to take away his escaping kit, he sawed his way out by a highly tempered saw and got back to England and continued with the job. For his work in the Second World War he was awarded many distinctions including the Silver Star with one oak leaf cluster, the Distinguished Flying Cross with oak leaf cluster, the Bronze Star, the Air Medal with seven oak leaf clusters and the Purple Heart. Colonel Yeager was transferred to Wright Paterson Field and in January 1950 he was re-assigned to Air Research Development Command, Flight Test Center, at Edwards Air Force Base, which some of them visited at Muroc last year when they visited America.

Colonel Yeager's first great world-shattering achievement was to pass through the sonic barrier, October 1947. This was done on the Bell X-l which was taken into flight on the B-29 and did its great flying after reaching high altitude. He actually took off in this aircraft under its own nower using rockets and did a very astonishing climb at supersonic speeds, achieving a rate climb of 13,000 ft./min. He thought that in itself was an astonishing feat.

For these records, Colonel Yeager was presented with the Mackay Trophy by the Chief of Staff of the United States Air Force, the Collier Trophy by the President of the United States and he was voted the "Airman of the Year" for 1951 by the Civil Air Patrol Cadets of fourteen nations.

President Eisenhower awarded Colonel Yeager the Harmon Trophy at the White House. The Junior Chamber of Commerce of the United States named him one of the ten outstanding young men of 1954. Since February 1955 he had been with the 50th Fighter Bomber Wing in Germany and it was said, and he was sure it was absolutely true, that he was glad to be back working with a tactical organisation because he enjoyed the team spirit.

This was a brief record of tremendous achievement over a comparatively short flying life.

The temperature distribution and thermal stresses are calculated in a configuration consisting of a cylindrical fuselage shell with bulkheads or frames. It is shown that at supersonic speeds thermal stresses are set up in a conventional fuselage structure as a result of the bulkhead restraint against circumferential expansion of the fuselage skin. The thermal stresses due to restraint by fuselage frames are usually less severe. The relative merits of various combinations of materials for the skin and the bulkhead diaphragm are discussed. Furthermore, the possibility of the use of light alloy bulkheads to alleviate thermal stresses is investigated. Diagrams are given for calculating maximum thermal stresses and stress-time variation for various rates of heat input in the fuselage skin due to aerodynamic heating.

The object of this paper is to present an analytical method of investigating the flexure of a non-uniform beam under transverse loading. A method due to Strandhagen for a uniform beam is extended to the case of a non-uniform beam, the deflection appearing in the form of a Fourier series, the coefficients of which are functions of the loading, the end-conditions, and parameters which define the non-uniform flexural rigidity of the beam.

A method is given whereby the shear stress-strain relationship of a material can be obtained from observations made during a torsion test on a hollow circular specimen. An examination is then made of the corrections necessary when using thin-walled specimens, and some advantageous definitions of the mean diameter of a tube are suggested.

The use of torsion tests to obtain shear stress-strain relationships is now well established and takes one of two forms. A thin circular tube can be used, it being assumed that the stress distribution is uniform across the wall thickness, or a solid circular bar can be used, the results being analysed by a method ascribed to Nadai. Swift has shown that these two methods give comparable results for moderate strains.

The compressible laminar boundary layer on a yawed infinite wing is considered in Ref. 1, where it is shown that the problem may be solved by a direct solution of the linearised equations of motion under certain assumptions. As an example of this procedure the boundary layer near a stagnation point was calculated. Tinkler has published solutions of the exact equations for the general Falkner-Skan case (Ref. 1) obtained on the M.I.T. differential analyser for several values of the parameter involved. It has been found that the numerical results of Ref. 1 were in error and the corrected results obtained by a new method are tabulated below. Tinkler's exact solution of the stagnation point flow for ω = 0·10 is also given for comparison, and it will be seen that there is close agreement