The last peril of the air we were warned against was that of the lee shore. In landing you should always do so against the wind. This is the first principle drummed into the beginners at the schools. If you make an "atterrissage" with the wind behind you, you roll along the ground so fast and so far that you are apt to meet an obstacle which will either wreck your machine or else cause it to turn a somersault. Yet, when making a landing against the wind, the force of the breeze blowing toward you will sometimes prevent you from coming down where you had planned. On many occasions I have seen aeroplanes remain practically stationary in the air, while descending, and sometimes even move backward in reference to the ground. This has to be considered by the pilot and grasped on the instant, or else he will surely come to grief by hooking some object in his descent. *THE RÉSERVE GÉNÉRALE DE L’AVIATION* The "Réserve Générale de l’Aviation," "R.G.A.," or, as it is more commonly known, the "Groupe d’Entrainement," is situated northeast of Paris, on the plains of Valois. It was there that General Maunoury, in September, 1914, launched his turning movement against the German right flank under General von Kluck, and helped save France in the great battle of the Marne. The country in this section is ideal for aviation, for the hills are low and rolling, and there are very few "obstacles." In a large forest—an "obstacle"—the village of Ermenonville lies. Here we were billeted, while the commanding officer of the reserve made his headquarters in the château of the Prince Radzivill, the "patron" of the neighborhood. The organization of the reserve is stupendous. There are four separate camps, one for each branch of aviation, and there are over one hundred machines in each camp. We were practically our own masters, and could make flights whenever and wherever we wished. The idea is that the pilots here have an opportunity of perfecting themselves and that, if they do not fly, why, then it is their own loss. Acrobatics and all sorts of feats are encouraged. Accidents occur every day, but we were here on "active service" and our time was far too taken up with our work for any one to pay much attention to the unlucky ones. That, at the front, is a duty reserved for the medical corps.