Besides the work it will have to do on the front (with which we will deal hereafter) the aviation of bombardment will, during the period of preparation, have to make numerous raids on the enemy’s rear, hurl destruction upon the aerodromes, and into the camps of the staff and reserves, blow up the important ammunition and food stores, attack the trains, destroy the railway lines, especially at the junctions, set the stations on fire, and attack all detachments and convoys on the roads. Briefly, the aviation should, during the preparation for an attack supplement at the rear the disorder created at the front by a prolonged bombardment. If these desiderata are complied with by sufficiently numerous and powerful aircraft, the enemy will find themselves in evident inferiority at the moment of attack. =3. Different kinds of aircraft.= There are several kinds of airplanes: BATTLE-PLANES. The importance of the fighting aviation far exceeds that of the other kinds, owing to the fact that whatever their mission, the latter cannot keep the air either on the front or during the raids back of the enemy lines unless they are protected against the attacks of the opponent’s aircraft by a sufficient number of lighter, swifter, and more easily manœuvred battle-planes. The organization of the fighting aviation ought, therefore, to claim the principal and most careful consideration of the commanding officer in charge of all the different services of the flying corps. Fighting machines must be very numerous, and piloted by cool, competent aviators, masters of their machines and possessing what, in France, our soldiers call “Cran”; _i. e._, Pluck. At the present moment there is an obvious tendency to abandon monoplanes in favour of small, very handy biplanes flying 220 kilometres an hour. Our renowned “aces,” such as the late Captain Guynemer and so many others, have, until now, fought single-handed, piloting and shooting at the same time. We are returning to the idea of placing two men on these fighting machines. Some of these are already fitted with two very light and extremely accurate machine-guns, the front one being fixed so as to shoot through the screw. This result has been obtained by the use of a device so marvellously accurate that the ball at its exit from the barrel of the gun never hits the blades of the screw speeding at more than one thousand five hundred revolutions a minute. For a long time, our French aviators operated separately, but the Germans having taken the habit of flying in groups, our aviators, in most cases, fly now in squadrillas so as to be able to help one another. The battle-plane aviators fly at great heights, hiding themselves behind the clouds, and, when they see an enemy machine below them, they drop on it with all speed and attempt, while keeping above it, to shoot it down.