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.