Before beginning the main subject of my lecture, the Society may perhaps wish me to refer to some of the outstanding events of the year.

The honour of the first flight round the world has fallen to the countrymen of Wilbur and Orville Wright, and well have they deserved it. We can realise to the full the courage, endurance and skill that they brought to their task; and we can share to the full the disappointment of those of their own party, and of their friendly French and British competitors, who had the misfortune to fall by the way.

The flights round Australia, though less spectacular, and covering less distance, are perhaps equally worthy of recognition. With practically no organisation, complete reliance had to be placed on the aircraft and engines, as well as on the pilots; there, was no possibility of effecting any but quite minor replacements.

In this paper it is proposed to deal with dopes and fabric as far as they relate to the problem of the production of a structural covering for aircraft which will maintain its tautness under varying conditions of humidity and also retain its strength after prolonged weathering.

Japanese mythology (i.e., prior to the sixth century B.C.) seems to contain no reference to flying. There is therefore no close parallel to the story of Daedalus and Icarus with which we are familiar. There are, it is true, many references to the descent from Heaven of gods and goddesses, but no details are given.

One of the very ancient “ No ” plays tells of an angel descending from the sky at Tago-no-ura wearing wings made from the feathers of the crane (Tsuru). Being somewhat tired after her flight, she removed her wings, which were stolen by a fisherman. On discovering her loss, her distress was such as to move the fisherman to return the wings, which he did on the condition that the angel would dance for him before flying away. This dance (Hagoromo-no-Mai) is one of the most graceful found in the “ No ” plays.

I thank you very much for the honour of your request to read this lecture before you.

In preparing this lecture I anticipated your permission to give you only some personal experience and my personal opinion regarding large all-metal seaplanes, for I know rather little about the machines of other constructors.

There is no branch of engineering where a big machine does not give a distinct advantage over an equally powerful combination of several small units. In our special case of the seaplane, these general advantages of the big unit are so obvious that they were recognised very early, and therefore I must not take your time by repeating them. I only mention the most outstanding quality of the large seaplane, i.e., its increased seaworthiness.

Illustrations to the Appendix of this paper were unfortunately omitted in the January number. The Appendix is therefore reprinted with the illustrations.

The rigid airship in its modern form is a German conception, but the nature of the strength calculations employed by the Germans has been a carefully guarded secret. When the U.S. Navy undertook the construction of rigid airships it was arranged to have one ship designed and built in the United States, the ZR. 1, and one ship designed and built in England, R.38 (ZR.2). Lacking practical information and experience, fundamental theory had to be resorted to in undertaking the design of ZR.i, and all available information had to be analysed,, compared and, so far as possible, tested. After the unfortunate loss of R.38 the calculations for ZR. 1 were reviewed and additional calculations and investigations undertaken.

The authors of this paper, under the direction of Rear-Admiral W. A. Moffett, Chief of the Bureau of Aeronautics, U.S. Navy Department, have been charged with the design of ZR.i and have had in the course of duty to make, or cause to be made, such studies and investigations as would assist in analysing and simplifying the problem as much as was possible in advance of full-scale experiments in flight.