Appleton, Victor – Tom Swift Jr 20 – And His Megascope Space Prober

60 MEGASCOPE SPACE PROBER

in liquid helium,” Tom explained. “Otherwise, unless they’re supercooled, the molecular motion sets up too much noise.”

“Whew! I guess that’s about as delicate as you can get, eh?”

Tom grinned. “After I get the set loaded with coolant, there’s a small cryostatic compressor inside that will keep the helium liquefied whenever the radio is in operation. Sort of a midget-sized refrigerator.”

Suddenly both boys jumped back as a cloud of white steam burst from the top of the radio housing! A deadly chill seemed to sweep through the laboratory.

“G-good grief! What happened?” Bud gasped, his teeth chattering.

Table tops, file cabinets, and laboratory equipment quickly became rimed with frost. The two boys shivered as Tom hastily shut off the flow of helium.

“I just broke Newton’s law of gravity!” Tom said in awe.

“Please, professor! No jokes!” Bud pleaded.

“It’s no joke; it’s a fact.” Tom explained that the filler neck connection in the base of the radio had fractured. The liquid helium had instantly crawled upward inside the radio housing in order to escape. “You see, liquid helium in this supercooled condition is what’s known as a ‘super-62 MEGASCOPE SPACE PROBER

fluid.’ It’s the only substance in the world that can spill upward all by itself.”

The white “steam,” Tom added, was condensed water vapor from the air which had been produced when the liquid helium evaporated and cooled the outside air.

“Boy, now I’ve heard of everything,” Bud said. “Better watch it, Tom. You’ll be a marked man if the police find out you just broke the law of gravity!”