"You mean that your weapon inflicts death with just a beam of light? That sounds impossible."
"But it isn't! I'll tell you about it." Pelton's eyes were glittering and his face was flushed: "Not more than a month and a half ago I was in Ecuador with Calhoun on leave of absence. We explored an extinct Andean volcano of particularly ghastly reputation. There I found a peculiar crystal, which, on analysis proved to be a complex compound of silicon, iron and the hitherto supposedly inert gas, krypton—I call it andite.
"It was just by chance that I discovered what terrible things andite could do. There was a big block of the material at the crater's western edge. The sun had been obscured by a cloud and, when it came out, its light struck the block, passed through it, and came out as a bluish beam. It hit my old friend and sent him on the long journey west. Thank God, it was not in vain!
"After a lot of effort I learned more about the wonderful properties of the crystal. You know that light is the vibration of an all-pervading medium sometimes called the ether, just as are radio waves. When a beam of light passes through andite, its rate of vibration is enormously increased; so that it exceeds by many thousands of times the vibratory rate of even Hadley's Q-ray which is used as an anaesthetic. This super-vibration is the crystal ray. It will penetrate four feet of solid lead and a much greater thickness of any other metal. When it strikes a man it produces within his blood a poison that is instantly fatal. The process is comparable with that which goes on in the leaves of a plant when starch is produced by the action of sunlight.
"The projectors of the crystal ray are merely specially constructed radio lamps, equipped with a receiver of wireless power, and fitted with a piece of andite which modifies the light.
"After I had learned what my discovery was capable of, I staged a demonstration before the best minds of America. They gave me the cooperation of the whole country and this is the result."
"But what was the necessity of building this enormous power plant?" inquired Jerry: "Couldn't the old stations supply the needed energy?"
"No," said Pelton; "The light produced in the ray projectors must be many times as intense as that produced by ordinary lamps, in order to be effective at any considerable range. Only this new power plant could furnish sufficient energy. The filaments in the projectors would only glow on the power supplied by the old outfits."
Momentarily the roar of terrorium shells and the flashing of magnesium flares waxed more intense in the air above. In the few minutes that the big generator had been running, the Americans had annihilated practically three-quarters of their foes. However, a few were trying to escape into the night with their lights turned off. One fifteen-hundred-foot monster was directly above at an altitude of not more than half a mile. Its guns belching with the fury of despair at a smaller but much more agile American ship that was rapidly approaching.
Suddenly the invaders scored a hit. The little vessel crumpled up and fell. The big ship was continuing its retreat away from the scene of battle when a bluish beam, originating from a projector in the neighborhood of Whitley Park, leaped up from the earth and struck it. The ray lingered over the whole expanse of its hull for a second and then died out. The dreadnaught continued to hurtle blindly on its way, its rocket-motors roaring full blast. It was headed straight for a sky-scraper, and a moment later it struck. A third of the building's height was sheared off; together with the twisted remnants of the ship the mass of steel and masonry fell with a terrific crash into the cleft of a dark street. There the airship still buzzed and hissed like a wounded insect.