The machine they employed was a military-type, weight-carrying biplane, and they took it in turns to steer. Their tour lasted several days; and, in one flight, extending over three and a half hours, they traversed a distance of 149 miles. Motor-cars, bearing spare parts, kept in touch with the airmen; the whole undertaking was admirably organised, from the military point of view. It is in work like this, of course, that definite progress is made. In connection with such long reconnoitring tours, a German officer of experience has placed upon record the view: "However good you may imagine your organisation to be, a practical test will generally reveal at least one or two false links in the chain; and, of flying, this is truer than of anything else. Once an air-corps is proficient, actual war conditions should be represented as frequently as possible. This will polish up the entire system, and make each unit sure of its work. Unless reconnoitring tests, carried out on a practical war basis, are frequently made, it is idle to assume that your corps is ready to do any valuable work during a campaign." There is no need, at any rate, to impress the wisdom of this observation upon the French military authorities. Whenever a long reconnoitring flight is accomplished, from one of the flying schools, the officer who is acting as observer is instructed to send a concise service telegram to Headquarters, describing the journey that has been made. It may be interesting to reproduce the text of such a message, in order to show the business-like way in which the French air-work is carried out. This was a telegram, for example, received in Paris in connection with a typical practice flight:— "Lieut, in command aeroplane 11 to War Office. Lieuts. Cammerman pilot. Vullieume observation officer. Left Mezieres 7.10 a.m. Passed over Vervins, Guise, St Quentin, landed north of Amiens at 9.55 a.m. to inquire direction aerodrome. Landed aerodrome 10.30 a.m. Voyage difficult owing mist, which frequently obscured ground. No incident." Messages, such as this, are now being dispatched and received daily, in connection with the flights organised at the French flying schools. The dispatching of such telegrams is, of course, only a detail of the general work; but it is one of those items, nevertheless, which needs practice to make perfect. In the arrangement of non-stop flying tests, the officers in charge of the French schools leave no stone unturned to promote the efficiency of their pupils. As a contrast to long tours, lasting several days, continuous flights, involving a return to the aerodrome before descending, teach an airman useful lessons. Three instances of such non-stop flights, selected more or less haphazard from the reports received, from day to day, in connection with French military aviation, are sufficient to indicate what excellent work is being done. They are appended:—