She was only two hundred feet in length—smaller than the mighty aerial battleships of the United States Navy. But despite her relative smallness, she could easily have wiped out, in a few minutes, the entire fleet of a hundred great aerial battleships which formed a cordon around Ted’s plant, to see her off, and to fire parting salvos. The air about this mighty fleet swarmed with every conceivable type of air craft from the small helicopter taxicabs to huge passenger ships. Escorted by this stupendous array of air craft, the Luna soared gracefully upward to a height of ten miles—the utmost distance to which any of the other craft could follow her—then shot toward the zenith with such speed that in less than a minute she was lost to the view of the beholders. Built for warfare of a type never previously contemplated by men of earth, she was a marvel of mechanical perfection and offensive and defensive efficiency. Her powerful atomotor could send her through space at a speed far greater than that attained by any of the planets in circling the sun—a speed so swift that no human eye could follow her movements. She had two sets of degravitors—one for offensive and the other for defensive purposes. Each of the four central turrets above deck mounted four cannon-like degravitors that would disintegrate the toughest steel up to a distance of twenty-five thousand miles, and other substances at lesser or greater distances according to their various cohesive powers. The two end turrets, fore and aft, each mounted six degravitors of the same size and power as the others, and midway between keel and rail each side of the craft bristled with twelve more of these potent projectors of destruction, which were in movable, ball-in-socket mounts, capable of being pointed in any direction. The defensive degravitors were much smaller and shorter than those to be used for offense, and instead of being pointed at the ends had short barrels and flaring blunderbuss-like muzzles. Instead of projecting their anode and cathode rays in nearly parallel lines, these weapons shot them out at widely diverging angles—scattered them so much that, placed as they were, their various rays united to form an invisible screen about the craft, impervious either to matter, light rays, or energy rays. When they were turned on the craft could have passed through a rapidly moving planetoid or even a planet without great shock, or danger either from heat, cold, or gravitational force. Sunlight, when striking them, was neither reflected nor absorbed, but converted into a white, innocuous luminescence, electrically and magnetically neutral, yet visible and transparent—a physical paradox that seemed like a ghost of real light.