But Captain Mignot evidently had his own ideas of military smartness, and these lads were all clean-shaven. They trooped in from their game, under that little cloud of shrapnel smoke that still hung in the sky, for all the world a crowd of overheated and self-conscious schoolboys receiving an unexpected visit from the master of the school. The path ended at the battery. In the centre of the guns was a raised platform of wood, and a small shelter house for the observer or officer on duty. There were five guns in pits round this focal point and forming a circle. And on the platform in the centre was a curious instrument on a tripod. "The telemeter," explained Captain Mignot; "for obtaining the altitude of the enemy's aëroplane." Once again we all scanned the sky anxiously, but uselessly. "I don't care to have any one hurt," I said; "but if a plane is coming I wish it would come now. Or a Zeppelin." The captain's serious face lighted in a smile. "A Zeppelin!" he said. "We would with pleasure wait all the night for a Zeppelin!" He glanced round at the guns. Every gunner was in his place. We were to have a drill. "We will suppose," he said, "that a German aëroplane is approaching. To fire correctly we must first know its altitude. So we discover that with this." He placed his hand on the telemeter. "There are, you observe, two apertures, one for each eye. In one the aëroplane is seen right side up. In the other the image is inverted, upside down. Now! By this screw the images are made to approach, until one is superimposed exactly over the other. Immediately on the lighted dial beneath is shown the altitude, in metres." I put my eyes to the openings, and tried to imagine an aëroplane overhead, manoeuvring to drop a bomb or a dart on me while I calculated its altitude. I could not do it. Next I was shown the guns. They were the famous seventy-five-millimetre guns of France, transformed into aircraft guns by the simple expedient of installing them in a pit with sloping sides, so that their noses pointed up and out. To swing them round, so that they pointed readily toward any portion of the sky, a circular framework of planks formed a round rim to the pit, and on this runway, heavily greased, the muzzles were swung about. The gun drill began. It was executed promptly, skilfully. There was no bungling, not a wrong motion or an unnecessary one, as they went through the movements of loading, sighting and firing the guns. It was easy to see why French artillery has won its renown. The training of the French artilleryman is twice as severe as that of the infantryman. Each man, in addition to knowing his own work on the gun, must be able to do the work of all the eleven others. Casualties must occur, and in spite of them the work of the gun must go on.