"Crew One, see to the lubrication of the cylinder valves and other parts," he cried; "use the L. F. liquid. Crew Two, examine all the connections of the Z wires. Crew Three, fill the main fuel tanks with the liquid terrorium preparation; Crews Four and Five will take care of the cylinder-head. Are all the cables securely fastened? We can't afford another mishap, you know. Good! Now start the crane."
Every man realized that it was vitally important that he should perform his task to the best of his ability in the shortest possible time; and every man responded to the will of his chief with the promptness of a well-oiled machine. In a moment the mass of aluminum alloy soared upward and settled into position.
To the south, and high in the air, a vast oval patch of white light, looking like the head of some enormous comet, had appeared. It had drifted ominously near, and from it there came a subdued roar. In it thousand of insect-like specks flitted, and from them tiny points of radiance leaped as though they were fireflies. It was the battle.
As they fought the two contesting fleets had done their best to get above each other, to gain the advantage of position. As a result their altitude was prodigious. They must have been fully twenty miles above the earth.
"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.