Joan, unknowing, drove home in the same reckless fashion. Ackerman prayed that they would meet no more careening cars; he was afraid that he might lose the sample if it caught in a swiftly moving body. This time, luck was with him.
Les Ackerman viewed his handiwork a week later. "'Tis a real monkey-motion," he told himself, "but it should work."
It was a real Rube Goldberg, of the type often concocted for an especial test. Many kinds may be seen in any laboratory, working madly to life-test various operating members, dropping parts against steel plates to see how many bumps they will take before becoming useless.
This was similar, but adapted to a singular purpose.
It was a straight reciprocating motion that passed an arm containing the sample of temperon back and forth through the trunk of a tree. The tree, of course, was in 'Real Time'; the machine in the 'time-space'. It would have simplified things if the treetrunk could be fastened to, but it was not; so the amount of drag was measured by the forces—back-forces—that tended to resist the motor that drove the gadget. At the end of each stroke, the arm entered a chamber that carried a radioactivity counter.
The tree was five or six miles from the laboratory, and only Ackerman knew where it was.
Ackerman, having been twice bitten, was thrice shy times ten. At this point, his own mother might have had trouble in convincing Ackerman that she meant only for his benefit.
At the end of another week, Ackerman was satisfied; he was certain. For the drag versus 'time' had passed through a wide peak. The radioactivity versus 'time' had been harder to unravel, for it possessed an irregular curve that Ackerman fought with for hours before it resolved sensibly into the superposition of several normal radioactivity curves.
The matching of the drag curve with one of the radio curves was simple, after that. And Les then spent another ten days figuring out which of the many resulting radio-isotopes of temperon was responsible for its extension through the barrier of time into the world of 'Real Existance'.