Free Tom Swift and His Space Solartron by Victor Appleton II

sufficient number to convert to a usable volume of air for breathing. "The solar wind barely makes a dent in the vacuum of space."
    "I see. So what’s your approach?"
    Tom picked up a series of sketches to show the modelmaker. They showed a pair of rectangular gratings, or grilles, comprised of a multitude of narrow criss-crossing tubes. "They look like garden trellises," Hanson commented. "How big do you want the first models to run?"
    Tom grinned. "Oh, not too big—about four acres ought to be plenty for test purposes."
    "Four acres!" Arv gasped. "For the prototypes? How in cosmic space do you expect to load them aboard the ship?"
    The young inventor laughed pleasantly at his friend’s reaction. "I have a trick up my sleeve. The tubes that each of the atom-collector lattices is made of will be molded from a new kind of super-malleable metal foil I’ve developed—I’ll give you the formula. It’s really pretty amazing. It’s tough and durable even when milled down to a thickness less than a tenth that of a human hair! You can fold it into a tight bundle and then, by running a weak electrical current through it, the material will completely unfold itself and return to its original shape. Reverse the current and it folds up again. By my calculations each four-acre bundle of transifoil will fold down into a cube just a yard or so across, and so light in weight—"
    Crash!
    The two looked up with a start to see a cascade of bottles and equipment tumbling from a big metal shelving unit next to the lab door. At almost the same instant the door, which had been standing half-open, slammed shut.
    "Someone was hiding behind those shelves!" Tom cried out in alarm and anger. "And listening to every word we said!"

CHAPTER 9
THE STOLEN VOICES
    JUMPING up from their chairs, Tom and Hanson rushed out into the corridor of the laboratory building, leaping across the slow-moving conveyor pathway, the ridewalk, that ran down its middle. But there was no sign of the mysterious eavesdropper in either direction. Checking the other laboratory rooms that fronted the long corridor, they found that no one had seen anything unusual.
    "But he could have slipped into a lab not in use and forced open one of the windows," noted Tom. "We have openable windows in some of the labs that have to be isolated from the air conditioning system."
    "He must have sneaked into your lab to get the lowdown on the plans for your new invention!" Arv said uneasily.
    Tom nodded, his face grim. "Maybe. And he also must be an employee of Swift Enterprises." It was an unpleasant thought that some trusted worker might be a spy. Yet no outsider could have slipped in past the ingenious radar system that monitored all visitors entering the grounds of the experimental station. And in truth, the company had dealt with disloyal employees on more than one occasion.
    "I’ll call Security and ask Ames to make a check," said Tom, returning to the lab.
    But the resulting security check turned up nothing worthwhile. "As far as I can tell, nobody was out of place anywhere on the grounds," Ames told Tom an hour later. "But tell me this, boss. Is there something about your solartron, or this new atom-collector component, that would make spying or stealing worth the risk of getting caught?"
    The young inventor shrugged. "The machine itself has a great potential for use in space colonization," he replied. "But I don’t see much use for it in daily applications here on Earth. It’s not like you can manufacture gold or diamonds with it. Just oxygen and nitrogen is hard enough!"
    Yet by the noon hour the purpose of the lab break-in had become all too apparent. "The digital chip has been stolen!" Tom exclaimed over the phone to Ames. "I had left it here in the lab last night, for downloading and analysis today. It’s gone! It looks like somebody riffled through the cabinets until he found it."
    "You almost caught him in the act," noted Harlan Ames. "When he heard you approaching in the