The subject I have to deal with in this paper is enormous, and of vital importance to the Empire, but it is only possible to touch very lightly on the possibilities of commercial aeronautics in the time allowed this evening. My opinion is that it will revolutionise the world not only from a commercial point of view, but from a humanitarian-pont, much more indeed than it has revolutionised warfare, although the effect on that is very great.

Before proceeding, I wish to say that I much appreciate the invitation to present this paper to your Society. The science of aeronautics has evolved at a great pace, and typifies what can be done with applied science, and the tangible results are so apparent that it would be superfluous to discuss them. It would .appear to me that the rapidity with which the efficiency has increased is due to the whole-hearted collaboration of the different branches of applied science and engineering, the honours being shared, after giving first place to the sporting instinct of the early flyer, by the physicist, the engineer, and the metallurgist. You will notice that my modesty places the metallurgist last. It is quite a confession to make, but it is a fact, nevertheless, that I accepted with pleasure your invitation to give this paper, principally because I have always taken a keen interest in the metallurgical side of aeronautics.

Ladies and Gentlemen,—I think perhaps the title of my paper requires a short explanation before beginning.

A little over three years ago I was honoured by being asked to read a paper on Hying before this Society, which I then called, “Three Years’ Flying Experience.” I need hardly say that paper caused me no small amount of anxiety in preparing, even then, when a mere description of an ordinary flight would deeply interest most people, because when I came to get down to it I had to ask myself what there was I could find to talk about that would interest the learned and technical audience I knew I should have to face.

It may seem rather presumptuous for one who does not himself fly to discuss, the dangers that may be met with in the air as though a landsman who had crossed the Channel a few times were to write on the navigation of a ship across the ocean. At the same time, it may be of some use to point out certain conditions of the atmosphere which seem to me to constitute dangers, although I may be mistaken in my estimate of some of these, and would welcome any information from pilots bearing on the subject. In fact, my paper is meant to elicit information rather than to give it.

In winding up with the paper of this evening a highly-successful session of the Aëronautical Society of Great Britain, the authors desire to express their appreciation of the honour of being invited to conclude the series of lectures and papers delivered during the last six months. They hope they will not be misunderstood wThen they venture to affirm that, both in the planning of the course to cover practically every section and in the high level of excellence of the individual papers, the present necessities and the future of the science ard practice of aeronautics have been admirably served.

The past year has been one of considerable development and progress in the affairs of the Society, more especially in respect to the large increase in membership, the resumption of the full activities of the Society, the establishment of a Joint Standing Committee with the Society of British Aircraft Constructors, and the transfer of the offices from Adam Street to much more suitable and commodious premises in Albemarle Street.

In addressing myself to the members of the Aeronautical Society of Great: Britain, the oldest institution of its kind in the world, I have to bear in mind that a section only of that membership is composed of designers of internal combustion engines. Therefore I have striven to make my remarks this evening as intelligible as possible to those who have not had such training.

From the time when man first made a bow and arrow or a wooden drinking vessel until now he has accumulated such an experience of the properties of wood that he has ceased to regard it as an unsatisfactory material.

Metals, too, whether as swords or ploughshares, may be worked with that precision and possess that du rability which cannot fail to be a source of satisfaction.

If fog be regarded as any condition of the atmosphere near the ground when objects at a distance are hidden by small particles in the air, it is convenient to divide fog into two classes-those in which particles are so small that they would take a long time to fall to the ground, and those in which the particles are large enough to fall fairly quickly, but in which the supply of particles is continually replenished, so that the air does not clear itself. In this second class would be included sandstorms, in which the supply of particles is replenished from below, and fine rain, in which they come from above. Pilots, however, are not much concermd with fogs of this class. In the first place, sandstorms do not occur in England; and in the second Place, on the occasions when a fine rain is indistinguishable from fog or mist, the clouds are very low, and a pilot would be unlikely to be flying in any case. I have therefore limited myself to fogs of the first class.

The accurate testing of aeroplanes is one of the many branches of aeronauticswhich have been greatly developed during the war, and especially during the last year. For some months after the war began a climb to 3,000 to 5,000 feet by aneroid and a run over a speed course was considered quite a sufficient test of a new aeroplane ; now we all realise that for military reasons certainly, and probably for commercial reasons in the future, it is the performance of a machine at far greater heights with which we are mainly concerned.