"Loud, isn't it?" he grinned. "Can you identify that any better?"
Wes Farrell threw up his hands. "I can state with positiveness that there isn't any varying field of anything that I know of that is at that frequency."
Channing just grinned. "Maybe it's just normal for that thing to vibrate."
"Like an aspen leaf?" asked Walt.
Channing nodded. "Or like my wife's jello."
Walt turned the dial of an audio generator until the note was beating at zero with the vibrating crystal. "What frequency does Arden's jello work at?" he asked. "I've got about four-fifty per second."
"Arden's jello isn't quite that nervous," said Don, puzzling.
"Taking my name in vain?" asked a cool and cheerful contralto. Don whirled and demanded, "How long have you been keyhole listening?"
Arden smiled. "When Walt Franks nearly runs me down without seeing me—and in his great clutching hands is a portable phonograph but no records—and in his eye there is that wild Tom Swift glint—I find my curiosity aroused to the point of visible eruption. Interesting, fellers?"
"Baffling," admitted Channing. "But what were you doing standing on odd-corners waiting for Walt to run you down for?"