Part 14 (2/2)

The young inventor's spirits were high when he finally returned to his laboratory and buckled down to work.

”I'll lick this problem yet,” he muttered. ”Those enemies of ours are clever, but if they can produce an undetectable sub, there's no reason why I can't do the same.”

Deep in thought, Tom idly fingered a microphone on his workbench.

”In fact,” the young inventor mused, ”why not go them one better? I'll invent a submarine that's not only invisible to sonar, but equipped to _see them_!”

CHAPTER XI

SQUARE-DANCE HOAX

Random hunches and circuit diagrams flashed through Tom's brain. ”The job will boil down to blotting out sonar waves and piercing the enemy's own 'wave-trap defense,'” the young scientist concluded.

As Tom struggled with the problem, he lost all track of time. A door swung open and high-heeled boots clumped on the floor tiles. Tom looked up and saw the portly, ap.r.o.ned figure of Chow Winkler entering.

”Hi, boss! Can I borrow a radio?” Chow asked. ”Kinda like a lil music while I wra.s.sle them pots an' pans in the galley.”

”Sure, pardner.” Tom pointed toward a portable radio on a shelf nearby.

Chow's leathery face broke into a grin as he picked it up. ”One o' them slick lil transistor doodads, eh?”

The cook flicked on the dial k.n.o.b and the tw.a.n.gy strains of Hawaiian guitar music came throbbing out. A split second later the volume swelled as the same music echoed back to them from the two-room apartment adjoining the lab, where Tom ate and slept when engaged in some round-the-clock experiment.

Chow was startled by the blare. ”You got a stereo hookup here, boss?” he inquired.

”Not exactly.” Tom explained that the music had merely been picked up by the mike on his workbench, then fed into the adjoining apartment and amplified over a speaker there.

Chow grinned, snapping his fingers to the catchy melody. ”Comes out even louder'n it does from the radio!”

”Yes, but the sound quality's not so good,” Tom said. ”You'd notice the difference with real stereo.”

Chow walked out with the portable, crooning contentedly to the music.

Tom frowned, trying to get his train of thought to focus once more on the submarine problem. But for some reason the business with the microphone and the speaker in the next room kept lingering in his mind.

Suddenly Tom exclaimed aloud, ”Say! I wonder if that's how the enemy sub blinds our sonar?”

The idea certainly seemed feasible. Suppose the submarine used a great many ”microphones”--or receiving transducers--to pick up the sonar pulses beamed out by another craft trying to detect it? These impulses could then be pa.s.sed on and sent out by speakers on the opposite side of the sub, and relayed along on their underwater path of travel.

Thus the sonar waves would appear to be striking no obstacle--and no echo would return to the sonarscopes on the search craft!

”Jumping jets!” Tom thumped his fist on the workbench in his excitement.

”I'll bet that's the answer, all right!” He grinned. ”Brand my boot heels, it's partly due to good old Chow!”

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