"See! They are almost upon us," shouted Pelton. "Hurry! Ten minutes more of delay and we will be too late! Doubtless they are already bombing the outskirts of the city." With all the speed they could muster the workmen bolted the cylinder-head into place. "Is everything ready?" cried Pelton. "Everything is ready," echoed Jerry Armstrong, his chief subordinate. "Then, stand back, out of danger!" Pelton twirled a few dials on the control board; and then, grasping the big black switch at its center, he pulled it far down. There was a series of ponderous throbs that rapidly grew into an easy humming. The engine and the generator to which it was connected, were in operation. Leaping in the network of wires far above were many bright flashes like the lightning of a violent thunderstorm. And now all eyes in Chicago had turned fearfully and expectantly toward the monstrous sea of light that was dropping plummet-like from the sky upon the city. The ships were only four or five miles above the ground now, and they could be seen quite plainly in the glow of their searchlights and magnesium flares. The American formation had been broken up and scattered. Apparently there was nothing that could prevent the Asiatics from completely crushing them within the next few minutes. Then they would destroy the city. Already an occasional bomb was falling, like the big raindrops that herald a summer thundershower. They contained the green chemical that gave off the gas which ate into human flesh like sulphuric acid. With mingled doubt, fear, and hope gnawing at his very soul, Pelton stared at the sky. Had he calculated correctly? For a few seconds nothing happened; then his heart leaped with a mighty exultation! From the bow of one of America's ships a faint beam of bluish light stabbed out and struck an enemy craft, sweeping it from stem to stern! It passed through the vessel as though she had been made of glass, instead of thousands of tons of metal. Immediately the dreadnaught began to blunder oddly as though completely out of control. What had happened to her occupants? A grim smile passed over Pelton's lips, for he knew! [Illustration: From the bow of one of America's ships a beam of bluish light stabbed out and struck an enemy craft. It passed thru the vessel as tho it had been made of glass instead of thousands of tons of steel.] Presently, other beams of blue light awoke--hundreds of them!--thousands of them! And other Oriental craft rushed about crazily, crashing into each other or hurtling earthward. At the very threshold of complete success, the alchemy of fate was changing Asia's victory into crushing defeat. Pelton Explains