The captain turned a lever, and a dynamo nearby began to revolve, while an arc lamp suspended from above glowed, glistened, and sparkled, as the current passed through the carbons. Soon it began a curious, musical buzzing, and the captain shut it off. "Merely an alternating current through an arc," he explained. "But the electric impulses sent out by that singing arc are of a wave length and frequency produced by no other means. They are just right to turn his two magnetic poles into one, and--away he goes." "I don't understand. Yes, I understand that you might reverse his polarity, or combine it, as you say, by some wireless method. But, which side are you on?" "The side of the Lord." "Look here, captain," said Felton, angrily. "That is the answer your double gave me when I asked him the same question last night. It means nothing. I am either a prisoner of war, or a guest entitled to consideration. Why do you treat me like a fool?" "Because you are a fool. You believe in the invulnerability of the battleship. Well, there is one of the best. Look at her." "I see. Destroyed, but not by you; by an enemy of yours. One who feared you." "Yes, as mediocrity fears intelligence, as the child fears the dark, the savage the gun of the civilized soldier--humanity as a whole the unseen, the unexpected, the invisible. The airship is potential, but not final--she can be seen." "And shot," said Felton, doggedly. "Did that battleship hit your airship? You know that she could not. The airship's limitations are contained in her visibility. She cannot be hit by shot or shell, but she can be seen, and projected into space." "Granted, but suppose she dropped a bomb on to your back before you saw her?" "She could not, except in the dark; then she would have to strike a knife edge, and it would be an accident--one chance in millions. We are constructed like a razor-back hog, to deflect falling bombs." "But you cannot deflect horizontal torpedoes," said Felton, looking up at the dome of the submarine. It looked curiously like the dome-shaped roof of the airship. "I know well," he went on, talking as was his wont among his fellow officers, "that if I could see your periscope tube with a telescope, I could hit you with one of my torpedoes." "Your torpedoes?" "I am torpedo officer of that battleship. I was on the turret top when you blew it up last night, and went up with it. I landed on the airship." "You are a member of that battleship's crew?" "I am." Felton dropped his eyes at the menace in the captain's voice. On the way his glance took in the curving walls of the submarine. They had become semi-transparent, and even as he looked they vanished, leaving a clear view of the sky and horizon with its string of fighting ships, pursued and pursuing. He was again in the airship, and the upright stanchions that he had first observed as anomalies in a submarine now served their legitimate purpose of supports to the roof.