These are instances only; the story of progress is everywhere the same. The wonderful national air force was built by the skill and intelligence of a few men out of the mass of material offered to them by the private pioneers. The work of these pioneers can best be concisely described in connexion with the various centres, or aerodromes, where they gathered together to put their ideas to the test of practice. Not all the early experimenters were attracted to these communities; some preferred to work in secret; but the most fruitful work was done in open fellowship. Among those who, in the days before aerodromes, devoted time and effort to the problem of flight, Mr. Jose Weiss deserves more than a passing mention. After experimenting with models, he devised a man-carrying bird-like glider, twenty-four feet in span, and in the year 1905, while flight was still no more than a rumour, flew it successfully on the slopes of Amberley Mount, between Arundel and Pulborough. His pilots were Mr. Gordon England and Mr. Gerald Leake. The former of these, in a wind of about twenty-five miles an hour, rose some hundred feet above his starting-point and then glided safely to earth again. The machine, says Mr. Weiss, who, shortly before his death in 1919, kindly furnished this account, had no vertical rudder, and relied on ailerons only, so that it was difficult to steer. 'The combination of ailerons', he adds, 'with the vertical rudder introduced by the brothers Wright was the factor which determined the advent of the aeroplane.' The advent of the aeroplane and its development for war purposes has given an air of antiquity to the researches of Mr. Weiss. Yet many subtle and delicate problems connected with soaring and gliding flight are still unsolved; there was no time for them during the war. Mr. Weiss was firmly convinced that in moving currents of air flight without an engine is possible, though he did not under-estimate the difficulties to be surmounted. His glider was inherently stable, and had funds been available, might have been made into an efficient power-driven machine. The Etrich glider, which was invented at about the same time in Austria and closely resembles the Weiss machine, became the model and basis for the famous German Taube type of monoplane.