An essay which is to be submitted in competition for the R.38 Memorial Prize may fairly presume a knowledge of airship history in recent years, and I shall here touch only on those circumstances which have influenced the writing of this paper. Between the cessation of airship construction in the autumn of 1921 and its revival in the summer of 1924, all branches of official research were discontinued by order of the Air Council, excepting an inquiry into the theoretical aspects of stress-calculation which had been urged by the Aeronautical Research Committee in its report on the disaster to R.38.

Aeronautics is a youthful study—a mere Cinderella of the Sciences, distinguished from her sisters by her tender years, by her guileless and impetuous disregard of the pinch of the financial shoe, and by her beauty.

That it is Applied Physics is to me the most inspiring definition of engineering; and if this be true for engineering in general, as I think it is, especially true is it of aeronautics. To illustrate the close association of these new studies with the work of physicists, I shall select a few of the more striking results of recent research.

Aviation is now entering upon a new and intensely interesting phase—one which will call for every scientific resource at our command. The materials of -construction are changing : wood is giving place to metal. The engine proves ito have most unexpected possibilities ahead of it through the increase of intake pressure; whilst the very lifting structure itself promises to change, for some purposes at least, from linear motion to rotary.

The term “Experimental Flying” is used to cover so many different subjects dealing with the development of practical aviation that I feel the title of this paper would be suitable for a volume of no small size, if I were to deal in detail with all it infers.