Even before 1939 the problems of high-speed flow were receiving a great deal of attention in the German aeronautical world. Their leading aerodynamicists, Prandtl, Busemann and Schlichting among others, had contributed largely to the theory of compressible fluid flow, and basic experimental research in the high-speed field had begun both at Aachen and at Göttingen. The activity in Germany in this particular field before the war was, in fact, much greater than in Britain, where Mr. Lock and his co-workers at the National Physical Laboratory carried practically the entire responsibility for such work.

The great increase in aircraft speeds during the war, and in particular the arrival of jet propulsion, completely changed our attitude to the subject in Britain. What had been an absorbing fundamental study became, quite suddenly, an important operational problem, looming large in every new fighter design.

The material herein presented was gathered as part of a research project for the Bureau of Aeronautics (Structures Branch) of the U.S. Navy on “Evaluation of High Strength Aluminium Alloys.” The Bureau has released this material for independent publication.

In this paper the physical constants determined are limited to elastic limit, yield stress, ultimate stress, modulus of elasticity, weight and ductility. The materials tested are primarily the new aluminium alloys 75 ST, R 301 T, and R 303 T.

To offer an immediate basis of comparison for aluminium alloys, the aluminium alloy at present in common use, namely 24 ST, was also tested. To extend the scope of the project still further, a few tests on magnesium alloy and stainless steel were included.

When at the beginning of the year I was invited by the Council of the Society to give a Paper on oil cooling I had had little more than average contact with the subject, but nevertheless I was startled when I discovered the extent of my ignorance. Inquiry showed that this lack of knowledge was fairly general, and that apart from highly technical articles by specialists, there was remarkably little up-to-date published data.

Serious rocket development was started in Germany in the years 1929–1930 by a few groups of private inventors. This work attracted the attention of the Army Weapons Group in 1933, and in 1937–1938 a special research and development station was set up at Peenemunde at the cost of 300 million marks, and the work was transferred from Berlin to this new station at about that time.

The evolution of bigger, better and faster aircraft of all classes received a great impetus during the War period. Now, when Peace has come and the Air Age is upon us, the development of more modern aircraft both for military defensive purposes and for civil transport uses, remains a matter of urgency if Great Britain is to retain her position as a great transport power. The tempo of development reached during the War must not be slowed down if we are to keep pace with, let alone excel, the United States.

It is indeed a privilege to be asked to deliver this, the Second Lecture inaugurated by the Royal Aeronautical Society as “ The British Commonwealth and Empire Lecture.” I feel particularly gratified at being asked to follow in the wake of so distinguished a pioneer in Commonwealth Civil Aviation as Mr. Hudson Fysh, who delivered the Lecture last year. I am, however, at the same time distressed by the sequence, because after reading the outline of experience and achievement which was presented in such graphic form by Mr. Hudson Fysh, I realise acutely that I cannot offer you anything comparable. There can be from myself no first-hand account of pioneering or achievement, neither am I a competent spokesman for any of the organisations which have played so great a part in building up the British contribution to world aviation.

A Meeting of the Royal Aeronautical Society was held in the Great. Hall of the Institution of Civil Engineers, Great George Street, Westminster, London, S.W.1, on Wednesday, 19th December, 1945, at which a paper by Professor N. Feather, Ph.D., F.R.S., entitled “ Atomic Disintegration ” was presented and discussed. In the Chair, the President, Sir Frederick Handley Page, C.B.E.

The idea of the disintegration of the atom appeared first—as a notion seriously entertained by a scientist of repute—in the hypothesis put forward by Rutherford and Soddy in 1903, in an attempt to explain the phenomena of radioactivity as known at that time.

During the war period, effort has been concentrated on the design of military aircraft, in the performance of which operational efficiency has been an overriding consideration. Speeds and powers have increased, resulting in a greater production of noise; but since noise reduction usually involves some loss of performance, perhaps from the additional weight of a soundproofing treatment, or the slight loss of engine efficiency which may accompany the use of an exhaust collector system, noise has had to be largely ignored. In the military machine, moreover, the incidence of noise on the ears of the crew is mitigated to an appreciable extent by the use of flying helmets incorporating well fitting earphones–a measure which it is hardly practicable to apply to civil machines.

In being honoured by the request to deliver a lecture on “ The Problems of Blind Landing,” I am set to some extent a task different from that normally presented to the Society's lecturers. In general the results of successful research are presented to you, whereas I am merely asked to outline the problems — with the implication that constructive suggestions for their solution may result. Personally, I feel that this is a most appropriate type of lecture, particularly in regard to a problem which embraces specialist fields in radio and radar, in aerodynamics and aircraft instruments, to an extent that few can claim to be expert in all.

The problem of blind landing can best be discussed after reviewing existing methods of blind approach and proposals now current for solving the landing problem.

In January, 1946, the writer was fortunate in being chosen as a member of a Scientific Mission sent to Japan by the Australian Commonwealth Government. As a member of this Mission he was required to investigate and report on the standard of design of military aircraft being produced by the Japanese at the end of the war.

The electrical measurement of strain is an art which has been developed gradually over a considerable number of years. It will be realised that the electrical measurement of strain includes the electrical magnification and measurement of a strain indicated by a non-electrical pick-up, such as a mechanical strain gauge, as well as the case of pure electrical measurement in which the pick-up unit itself operates electrically.

The principal reasons for the popularity of electrical gauges are their ability to record data at a station remote from the point of application of the gauge, thus allowing gauges to be attached in positions which would be inaccessible for direct measurement by mechanical or optical means, and the high dynamic response of the electric gauge which renders the gauge invaluable for dynamic work.

The regular operating heights of aircraft, both civil and military, are continually increasing until now regular flights within the stratosphere are planned. There is, therefore, much practical interest in the meteorological conditions to be found in the stratosphere and upper troposphere. For about half a century meteorologists have been sending up small balloons carrying recording instruments which measure the temperature and pressure at heights up to 60,000 ft. or more, while recently radio transmitters have been incorporated in the instruments which transmit the temperature and the pressure to the ground station. By following the path of the balloon either by sight or by radio direction-finding, the velocity and direction of the wind at the various heights can also be found. From measurements made in these ways meteorologists have for many years known the general distribution of temperature and winds up to great heights.

Beryllium, though of increasing application in the metallurgical and electrical industries, must still be classed as a relatively uncommon element. This would appear to be chiefly because no large scale application of the metal has yet been made; most commercial applications involve the addition of small amounts of beryllium to other metals, notably copper.

If a large scale use for beryllium were to be discovered, there would be little difficulty in the production of sufficient metal to fulfil a reasonable .demand. Its ores are widespread, but unfortunately are seldom found in heavy local concentrations. The processing of these ores is somewhat difficult on a commercial scale, but not prohibitively so. Extensive researches have been made on these problems, because of the incentive given by the exceptional “lightness” of beryllium, its high melting point and particularly, by its high modulus of elasticity.