The output of the factory was small, almost insignificant, compared with the efforts being made by foreign nations. Colonel Capper preferred not to attempt the construction of rigid airships till more was known of them. The Zeppelins were the only reputed success, and no Zeppelin, at that time, had succeeded in making a forced landing without damage to the ship. But the output of the factory is no true measure of the progress made. The officers in charge worked with an eye to the future. Early in 1906 a proposal was put forward by Brevet Colonel J. D. Fullerton, Royal Engineers, and was warmly supported by Colonel Templer, for the appointment of a committee consisting of military officers, aeronauts, mechanical engineers, and naval representatives, to investigate the whole question of aeronautics. A modified form of this proposal was put forward three years later, in 1909, by Mr. Haldane, then Secretary of State for War. He invited Lord Rayleigh and Dr. Richard Glazebrook, the chairman and the director of the National Physical Laboratory, to confer with him, and asked them to prepare for his consideration a scheme which should secure the co-operation of the laboratory with the services, thus providing scientific inquiry with opportunities for full-scale experiment. A scheme was drafted; it was discussed and approved at a conference held in the room of the First Lord of the Admiralty, and was submitted to the Prime Minister, Mr. Asquith, who took action on it, and appointed 'The Advisory Committee for 'Aeronautics', under the presidency of Lord Rayleigh. Seven of its ten members were Fellows of the Royal Society. The chairman was Dr. Glazebrook. The Army was represented by Major-General Sir Charles Hadden, the Navy by Captain R. H. S. Bacon, the Meteorological Office by Dr. W. N. Shaw. The other members were Mr. Horace Darwin, Sir George Greenhill, Mr. F. W. Lanchester, Mr. H. R. A. Mallock, and Professor J. E. Petavel. To these, soon after, were added Mr. Mervyn O'Gorman, when he took over the charge of the balloon factory, and Captain Murray F. Sueter, R.N., who deserves not a little credit for his early and persistent efforts to foster aeronautics in the navy. The great value of this committee was that it brought together the various bodies concerned with aeronautics, and combined their efforts. In particular, it gave to the new science the highly skilled services of the National Physical Laboratory, which organized at Teddington a new department, with elaborate plant, for the investigation of aeronautical questions. From this time onward the National Physical Laboratory worked in the closest co-operation with the balloon factory. Mathematical and physical investigations were continuously carried on at the laboratory, and improvements suggested by these researches were put to the practical test at the factory. Questions of air resistance, of the stresses and strains on materials, of the best shape for the wing of an aeroplane and