On days (like to-day) when the weather makes flying impossible, the fellows sleep late, make a long, luxurious toilet, breakfast, and stroll down to the hangars, where they potter around their "zincs," feeling over the wires, adjusting the controls, tinkering their machine-guns, or perhaps fitting on some sort of new trick sight. Sights are a hobby with every pilot and nearly every one has different ideas on the subject, advocating telescopic or open, one or two-eye outfits. Then, if one is extra careful, he takes out the long belt of cartridges, feels each bullet to make sure it is tightly crimped in the shell, and pushes and pulls the shells until all are exactly even. "Jams" are the curse of this game, and no amount of trouble is too much, if it insures a smooth working gun. Some jams can be fixed in the air, but others render you defenseless until you can land. Each pilot has his own mechanic, who does nothing but look after his bus, and is usually a finished comedian in addition to being a crack mechanic. In truth, I never ran across a more comical, likable, hard-working crew than the French aviation mechanics. They are mostly pure Parisian "gamins"--speaking the most extraordinary jargon, in which everything but the verbs (and half of them) is slang, of the most picturesque sort. Quick-witted, enormously interested in their work, intelligent and good-natured, they are the aristocrats of their trade, and know it. You should see them when they go on leave. Jean or Chariot, ordinarily the most oily and undignified of men, steps out of the squadron office arrayed in a superb blue uniform, orange tabs on his collar, a mirror-like tan belt about his waist--shaven, shorn, shining with cleanliness, puffing an expensive-looking, gilt-banded cigar. Is it fancy--or is there a slight condescension in his greeting? Well, it is natural--you can never hope to look so superbly like a field-marshal. A little crowd of pals gathers around, for it is just after lunch; and presently the motorbus draws up with a scream of brakes and a cloud of dust. The motor has "AV" in big letters on the side, and its driver (not to be confounded with any mere ambulance or lorry chauffeur) would feel it a disgrace to travel under forty miles an hour, or to make anything but the most spectacular of turns and stops. The driver produces a silver cigarette case, passes it round, takes a weed, taps it on his wrist, and chaffs the permissionnaire about a new godmother on whom he is planning to call in Paris.