"Gravitation is only one phase of magnetism. In magnetism, repulsion equals attraction. By reversing our polarity we are repelled from the earth at the speed of a falling body, but, of course, at a tangent." "It's beyond me," said Felton. "Of course, that tangent would take you westward at the speed of the sun." "In a succession of jumps--yes." "But how do you change your polarity?" asked Felton, becoming interested. "There is your ship down there, nearly beneath us." And the interest was crushed. Felton looked down. The light was stronger now, and he could dimly see on the surface beneath the indefinite outlines of a battleship toward which the airship was heading. Not a light could be seen on her. Her fires were quiet; not a flare shone from her funnels. Though there was fighting at a distance, this craft was not engaged in it. Slowly, from the lofty point of view, she moved along on a course that crossed the course of the airship, and slowly the latter turned and followed, soon dropping squarely in her wake--if such term may be used--a full half-mile above. The engine now accelerated its speed, increasing its volume of noise; and this noise must have been heard on the battleship. A sudden illumination was seen--like a flash of heat lightning--then came the singing of a projectile, and with it the report of the gun. "Oh, fudge!" said the captain, gently and pityingly. "Go ahead, boys." It was now light enough for Felton to examine the faces of these men. To his surprise they were young, almost boyish. They were not in uniform. Their dress and faces were as commonplace as could be found in a factory; only the tall, thin young captain showing in voice and expression the signs of study and thought. He twirled the wheel, manipulated levers and valves within reach, and watched, downward through the slits, the big craft beneath. The sun was rising in the east, and Felton could make out the details of the ship below--his own ship, with its familiar bridge, turrets, and superstructure, and an enormous, gaping hole forward where once had been the twelve-inch turret. Far to the south and east were other ships, pursued and pursuing, but which was friend and which enemy he could not make out. Warships, like bicycles, had become standardized. A small, round shot was dropped over, and Felton watched it descend until it disappeared from sight. But soon a scarcely perceptible splash was seen--a little astern and to starboard, and the captain moved the wheel and turned a lever. Another shot, or finder, went down, and this splashed nearer. Then they lifted a pointed shell, vaned like a dynamite projectile, held it poised until the captain gave the word, and dropped it. It went down true as a plummet, and went out of sight. But its effects were soon seen in an uplifting of the quarter-deck close to the stern, and the rising of a cloud of yellow smoke.