During the lecture on structural testing given by Dr. Pugsley to the Royal Aeronautical Society, reference was made to the work done at Weybridge on the strength testing of aircraft wings, and during the discussion the lecturer suggested that details of this work should be submitted to the Society for publication. This paper attempts to give a brief outline of some of the more interesting developments which have taken place during the war period, together with a few notes on the arguments which led to the adoption of the final form of test gear.

Introducing the paper Air Commodore Merer pointed out that the Americans, the French and the British were concerned in a close partnership in the Air Lift, but the Americans carried by far the larger portion of the load delivered into Berlin. The spirit of comradeship and endeavour which that joint task engendered was one of the heartening experiences of the operation and beyond all praise.

In these days of long distance flights across large stretches of ocean aeroplanes will make considerable use of radio direction-finding apparatus, enabling them to keep their course on to a transmitting station at their goal. Over the Atlantic, for example, a series of beacons all the way across would be quite impracticable. The following is an analysis of the course flown by an aeroplane under these circumstances, showing also the increase in flying time over that on a compass course, and also the maximum deviation from the compass course.

The fact that attention must be given to stiffness as well as strength in aeroplane design is now generally recognised. The provision of adequate strength alone is not sufficient to ensure that an aeroplane is immune from such troubles as flutter, loss of lateral control due to twisting of the wing and wing divergence. This is illustrated by the case of the Puss Moth. As shown in R. and M. 1645 this machine was examined in detail by the Aeronautical Research Committee and found to be completely satisfactory as far as the existing official airworthiness requirements were concerned, and yet it experienced failures which were attributed to flutter, an instability involving the stiffness of the wings and tail.

In the earlier stages of the investigations into these stiffness problems it appeared to many practical people that the work. was of academic interest only. As a matter of fact it was of subsidiary importance while operational speeds of aeroplanes were relatively low, but the higher speeds of the modern aeroplane make such problems of direct practical interest.

It is just one hundred years ago, towards the end of March, 1843, that the invention or design of the first power-driven aeroplane, Henson's so-called “Aerial Steam Carriage,” was made public to the world at large. The centenary marks an important step in the history of heavier-than-air flight, and in view of the development arrived at in the aeroplane of to-day—its great size, immense power, long range, and astonishing speed—the event assumes, in retrospect, a greater interest and significance than has been hitherto accorded to it. It is fitting, therefore—the more so in that the ‘inventor’ was an Englishman—that this notable occasion should not be allowed to pass unnoticed in the pages of the Royal Aeronautical Society's Journal. There is, moreover, the additional reason that the Society can claim an indirect connection with Henson's project, in as much as John Stringfellow, who was closely associated with Henson in their joint struggles to produce a model flying-machine, was one of the Society's most active and enthusiastic members in its early years.

In endeavouring to present a paper on the relative problems of supercharging aircraft and motor-car power units, the author wishes to convey at the outset that no attempt is being made to give a scientific investigation of air compression, but rather to review the present stage of supercharger development, the difficulties which have to be met by the engine designer in applying such a device to a high-speed petrol engine, and with the hope of stimulating from this review a discussion on the possible advantages to be obtained thereby.

For the purpose of this paper, supercharging an internal combustion engine may be defined as :–The filling of the cylinder during each cycle by mechanical means in the form of a pump, with a greater amount of charge than would be possible with natural aspiration.