To determine how much credit for the brilliant achievement I have tried to outline belongs to the skill and adaptability of British airmen, and how much to successful organisation, would be difficult and rather unnecessary. But it is obvious that those who guided the R.F.C. from neglected beginnings to the status of a great air service had a tremendous task. Only the technical mind can realise all that it has involved in the production of trained personnel, aeroplanes, engines, aircraft depôts, aerodromes, wireless equipment, photographic workshops and accessories, bombs, and a thousand and one other necessaries. Many thousand pilots have been trained in all the branches of war flying. The number of squadrons now in France would surprise the layman if one were allowed to make it public; while other squadrons have done excellent work in Macedonia, Egypt, Mesopotamia, East Africa, and elsewhere. Mention must also be made of the Home Defence groups, but for which wholesale Zeppelin raids on the country would be of common occurrence. How to make best use of the vast personnel in France is the business of the staff, who link the fighting members of the corps with the Intelligence Department and the rest of the Army in the field. To them has fallen the introduction and development of the various functions of war aircraft, besides the planning of bomb raids and concerted aerial offensives. On the equipment side there is an enormous wastage to be dealt with, and consequently a constant cross-Channel interchange of machines. The amount of necessary replacement is made specially heavy by the short life of effective craft. A type of machine is good for a few months of active service, just holds its own for a few more, and then becomes obsolete except as a training bus. To surpass or even keep pace with the Boche Flying Corps on the mechanical side, it has been necessary for the supply department to do a brisk trade in new ideas and designs, experiment, improvement, and scrapping.