"Rifles began to crackle from the Prussian trenches, and to his amazement, after firing a few rounds in reply, the French infantrymen ran for the cover of the brush. He saw the reason for this a moment later when a big troop of German cavalry topped the rise of ground and swept on toward the French, followed by the charging infantry of the Germans." [Illustration: HIS FIRE SAVED THE DAY.] "Some time since, Mattia had slipped from his dugout. He was determined to miss nothing of what was going on. He saw his own infantrymen take to the communicating trenches and disappear, plainly as a part of the plan. "Then the machine guns began to play. The mounted German detachment was close upon them before the hidden French machine guns opened up. All down the line to the right he could hear French machine guns pouring their fire into the approaching horsemen. Those who were not killed or who had not fallen wounded from their horses were turned back. "Mattia, in his excitement, crawled along one side of the communicating trench toward the machine-gun emplacement. He was shocked to see that more than half of his machine-gun crew already were dead or wounded. Now the German artillery, which he could not see, began shelling the French positions. A shell exploded in the trench occupied by his comrades, and Mattia was hurled violently into the communicating trench. "When the smoke had cleared away Mattia ran forward. The machine gun was silent, though others down the line were very busy. It was a strange sight for a boy to gaze upon. All his comrades were now lying in the trench, either killed or badly wounded. "The German infantry, in close formation--meaning close together--was coming on steadily. Down the line the French were holding them back, but in Mattia's trench there was no opposition. "The boy collected his wits, uttered a gasp, then sprang to the silent machine gun. A half-used strip of shells was in the gun and other strips were close at hand. "Little Mattia began to work the machine gun. He swept the field with it as far as it would reach to the right and the left, sending a rain of bullets into the enemy. Even after the strip was exhausted he kept on working the gun, not realizing that it was out of cartridges. Discovering this finally, he reloaded and began firing again. "His fire saved the day for the French, because, had Mattia failed to serve the gun, the Germans soon would have broken through the line and that would have lost the battle for the French. "At last the German line began to waver; it stopped, then began a retreat on the run, followed by the bullets of the machine gunners. Mattia was yelling and whooping as he pumped away with his weapon, elevating its muzzle a little from time to time that he might be sure to reach the fleeing men. "Shells had been bursting about him all the time and were still bursting.