Almost immediately another Farman sailed across the battery and signaled. As it did so the order came from the captain, to the lieutenant in charge of the three guns on the right. "Line up with Farman D 63, range 4700 meters."
The men stood at attention, all eyes riveted on the disappearing machine. Every second a voice would call out: "27, 27 and a half, 28, 28 and a half," and so on, and at each call the gun pointer would turn a small wheel, and the gun muzzle of the gun would move up a trifle. Soon a puff was plainly visible below the airplane.
"Tirez!" shouted the officer, and instantly there was a sharp, crashing roar. The aeroplane had, in the meantime, made a turn, and a puff appeared above the machine.
"Too high!" shouted the officer. Two more puffs appeared. "Two degrees lower!" was the next order.
The guns were reloaded before the foregoing orders were completed. Bang! bang! bang! Again another signal; still too far overhead. Another adjustment, and another round. The flying machine sent up a succession of puffs, and the lieutenant's face glowed with pleasurable excitement, as he shouted: "You have it. Give them forty shots; then depress."
While this was going on the three other guns were just as busy. The guns were pointed diagonally across the river, where the hills in the distance seemed to be constantly covered with a smoke.
"I notice that they have lots of smoke over there, so it is hard to tell where to fire," said Alfred, as he stood alongside the captain.
"That is true," he answered. "Our guns use smokeless powder, and that will aid us in concealing our position. If we used the same powder they use in shelling Devil's Cut, we wouldn't last a day."
Alfred understood why so much care had been taken to cover up the guns, for the Germans had guns which would reach as far as the 75's, but the question was how to locate the batteries. In this particular the French were superior, as well as in the ability to handle the guns rapidly and accurately, for it must be admitted that the French had easily taken the lead in the use of heavy ordnance.
It did not take long to fire forty shots. There was only a short cessation after the prescribed number had been let loose. The Farman machine came up close. It signaled.