The completeness and detail of this statement certainly surprised the officers who received it. No one, save a well-trained military observer, could have presented such a report. Its value was self-evident. It revealed, indeed, in a manner that was undeniable, the extremely useful work which could be done, in time of war, by a well-handled scouting aeroplane. II. Second conclusive test—Detecting an army in retreat—France’s determination to possess an air-fleet. On another early-morning flight, during these same Picardy manœuvres, Lieutenant Sido and Adjutant Menard made a second important aerial reconnaissance, surveying a specified tract of country occupied by the "enemy." This was how they presented their report:— 5.56 A.M.— At Halloy, a cyclist company. 5.59 A.M.— Thieuloy—Sixteen squadrons of cavalry and six batteries at the southwest entrance to the village. 6.5 A.M.— South-west of Rothois—At the north point of Malmifet wood, a company and two batteries of artillery on the march towards Marseille-le-Petit. 6.7 A.M.— Haute-Epine—Northern entrance to the village, one company of infantry to the right and one to the left of the road. One company at point 188. One company in the village of Haute-Epine. 6.9 A.M.— At the cross-road to Lihus, a squadron of dragoons concealed behind the edge of the wood. 6.14 A.M.— On the road Cievecoeur-Marseille south of Lihus, a squadron on the march towards Marseille-le-Petit, and a troop in the village of Lihus. 6.16 A.M.— On the Lihus-Potangy road, a squadron and two machine-guns marching towards Marseille-le-Petit. 6.19 A.M.— South-west entrance to Cieve-coeur, three regiments of cavalry, including cuirassiers, and six batteries of artillery, in assembly formation. "The value of these two reports," declared one of the chief French military experts, "cannot be overestimated. Each one exposed the dispositions of the enemy, and the information was obtained in a remarkably short space of time." As regards the second report of the two air-scouts, it provided one remarkable instance of the practical value of the aeroplane in time of war. Upon the night before the airmen carried out their reconnaissance, the troops they were observing had been heavily attacked, and the Commander-in-Chief for whom they were acting was particularly anxious to know whether his enemy intended to hold its ground, or was about to fall back. The aerial report, when received, threw a clear light upon this point. Mainly cavalry and rear-guards had been detected during the flight. It was obvious, therefore, that the enemy was in retreat. Such results as these convinced the military experts who were studying the manœuvres that the future of the aeroplane, at any rate from the reconnoitring point of view, was practically assured.