At three o'clock one morning in June, 1915, he discovered a Zeppelin returning from bombing towns along the east coast of England. The Huns shot Captain Fryatt because, as they said, he was a non-combatant and tried to defend himself. The rule that non-combatants should not attack military forces was made with the understanding that military forces would not war on non-combatants. But law, or justice, or agreements never are allowed by the Huns to stand in their way. This Zeppelin was returning from a raid in which twenty-four were killed and sixty seriously injured, nearly all women and children, and all non-combatants. Lieutenant Warneford well knew of the dastardly deeds of the Zeppelins, and he immediately gave chase, firing as he approached. The Zeppelin returned his shots. He mounted as rapidly as possible so as to get the great gas-bag below him, until he reached over 6000 feet and the Zeppelin was about 150 feet directly below him. Both were moving very rapidly, and to hit was exceedingly difficult, but he dropped six bombs, one after the other. One of them hit the Zeppelin squarely, exploded the gas-bag, and set it afire its entire length. The explosion turned Lieutenant Warneford's airplane upside down, and although he soon righted it, he was obliged to land. He was over territory occupied by the Germans and he landed behind the German lines, but he succeeded in rising again before being captured, and returned to his hangar in safety, to tell his marvelous story. The Zeppelin and its crew were completely destroyed. A few days later Lieutenant Warneford was killed. One of the greatest air duels, between airplanes, was during the Battle of Vimy Ridge. At that time Immelman was as great a German ace as were Boelke and Richthofen later, and Ball was the greatest of the English. One morning Ball learned that Immelman was stationed with the Germans on the opposite line, and carried him a challenge which read: CAPTAIN IMMELMAN: I challenge you to a man-to-man fight to take place this afternoon at two o'clock. I will meet you over the German lines. Have your anti-aircraft guns withhold their fire while we decide which is the better man. The British guns will be silent. BALL. Ball dropped this from his airplane behind the German lines, and soon afterward Immelman dropped his answer behind the British lines: CAPTAIN BALL: Your challenge is accepted. The German guns will not interfere. I will meet you promptly at two. IMMELMAN. A few minutes before two, the guns ceased firing, and all on both sides fixed their eyes in the air to witness a contest between two knights that would make the contests of the days of chivalry seem tame.