When two opposing armies both have large fleets of war aeroplanes, and these machines take the air in squadrons, prior to a battle, what will happen when they come in contact with each other? The question is one which the greatest military experts are discussing. Obviously, there will be an aerial battle, each aeroplane corps seeking to cripple the other. Each Commander-in-Chief will in fact desire, above all else, to obtain supremacy of the air. If he can do so, it will have the effect of seriously handicapping his opponent. Thus—probably waged with light guns firing explosive shells—the next great war will begin, not on earth, but several thousand feet in the air. Claude Grahame-White. Harry Harper. London, 1912. *CONTENTS* PREFACE ........................................................... FIRST SECTION REVIEW OF PROGRESS PRIOR TO THE FIRST MILITARY TESTS OF AEROPLANES ..................................................... I. Dawn of flight—Encouragement in Europe and America—England’s lost opportunities—The pioneers. ................................ II. First practical flights—The Wright brothers; the Voisins; Farman—The cross-Channel flight. ................................ III. Aeroplanes at Rheims, 1909—Wright, Voisin, Farman, Blériot, Antoinette—The Gnome engine—First military orders. .............. IV. The human factor—Growing skill of airmen—Feats of 1910, as compared with those of 1909—Cross-country flying. ............... SECOND SECTION FIRST EXPERIMENTS WITH AEROPLANES IN THE FRENCH AUTUMN MANOEUVRES, 1910. .......................................... I. The historic Picardy tests—First official report upon movements of troops, as gleaned by aeroplane. ............................. II. Second conclusive test—Detecting an army in retreat—France’s determination to possess an air-fleet. .......................... THIRD SECTION THE GROWING AIR-FLEETS OF FOREIGN NATIONS ........... I. Activity in France—Two hundred machines at the end of 1911; a thousand promised by the year 1914. ............................. II. The great French tests of military aeroplanes—Striking results obtained—Era of fast, "air-worthy," weight-carrying machines. ... III. Germany’s aerial policy—Secret energies in creating a fleet of war aeroplanes—Rivalry with France. .......................... IV. Progress in Russia, America, and other countries-England’s position in the autumn of 1911. ................................. FOURTH SECTION IMPORTANCE OF ORGANISATION IN THE USE OF WAR AEROPLANES ........................................................ I. French plans for the concerted use of squadrons of machines in time of war. .................................................... II. Value of air-stations—Selection of landing-grounds—Preparing air-maps.