each trip, though this was no great quantity individually, it had mounted up in the ten trips she had made. The "Cephid," her sister ship, had gone along on seven of the trips, and added to the total.
But at length the apparatus was set up. It was peculiar looking, and it employed a great deal of power, nearly as much as a UV beam in fact. McLaurin looked at it sceptically toward the last, and asked Buck: "What do you expect it to do?"
"I am," said Kendall sourly, "uncertain. The result will be uncertainty itself."
Which, considering things, was a surprisingly accurate statement. Kendall gave the exact answer. He meant to give an ironic comment. For the mathematics had been perfectly correct, only Buck Kendall misinterpreted the answer.
"I've followed the math, with mechanism all the way through," he explained, "and I'm putting power into it. That's all I know. Somewhere, by the laws of cause and effect, this power must show itself again—despite what the damn math says."
And in that of course, Kendall was wrong. Because the laws of cause and effect didn't hold in what he was doing now.
"Do you want to watch?" he asked at length. "I'm all set to try it."
"I suppose I may as well," smiled McLaurin. "In our close-knit little community the fate of one is of interest to all. If it's going to blow up, I might as well be here, and if it isn't I want to be."
Kendall smiled appreciatively and replied: "Let it be on thy own head. Here she goes."
He walked over to the power board, and took command. Devin, and a squad of other scientists were seated about the room with every conceivable type and combination of apparatus. Kendall wanted to see what this was doing. "Tubes," he called. "Circuits A and D. Tie-ins," he stopped, the preliminary switches in. "Main circuit coming." With a jerk he threw over the last contact. A heavy relay thudded solidly. The hum of a straining atostor. Then—
An electric motor, humming smoothly stopped with a jerk. "This," it remarked in a deep throaty voice, "is probably the last stand of humanity."
The galvanometer before which Devin was seated apparently agreed. In a rather high pitched voice it pointed out that: "If the Lunar Fort falls, the earth—" it stopped abruptly, and an electroscope beside Douglass took up the thread in a high, shrill voice, rather slurred. "—will be directly attacked."
"This," resumed the motor in a hoarse voice, "will certainly mean the end of humanity." The motor gave up the discourse and hummed violently into action—in reverse!
"My God!" Kendall pulled the switch open with a sagging jaw and staring eyes.
THE men in the room burst into sudden startled exclamations.
Kendall didn't give them time. His jaw snapped shut, and a blazing light of wonderous joy shone in his eyes. He instantly threw the switch in again. Again the humming atostor, the strain—
Slowly Devin lifted from his seat. With thrashing arms and startled, staring eyes, he drifted gently across the room. Abruptly he fell to the floor, unhurt by the light Lunar gravity.
"I advise," said the motor in its
