as you can."

"Dat's whut I will, Massa Tom. Golly! ef dat no 'count giant was heah
now he'd see he ain't de only one whut's got muscle. I'll pull good
an' hard, Massa Tom."

"Yes, that's what I want you to. Now I guess we're all ready. Can you
see, Dad--and Ned and Mr. Damon?"

"Yes," they answered. They stood near the side wall of the shop, while
Tom and Eradicate were at the testing block, on which the motor, with
the noise-eliminating devices attached, had been temporarily mounted.

"All ready," called the young inventor, as he turned on the gas and
threw over the electrical switch. "All ready! Pull the starting lever,
Rad, and when it's been running a little I'll throw on the silencer and
you can see the difference."

The motor began to hum, and there was a deafening roar, just as there
always is when the engine of an aeroplane starts. It was as though half
a dozen automobile engines were being run with the mufflers cut out.

"Now I'll show you the difference!" yelled Tom, though such was the
noise that not a word could be heard. "This shows you what my silencer
will do."

Tom pulled another lever. There was at once a cessation of the
deafening racket, though it was not altogether ended. Then, after a
moment or two, there suddenly came a roar as though a blast had been
let off in the shop.

Tom and Eradicate were tossed backward, head over heels, as though by
the giant hands of Koku himself, and Mr. Damon, Ned, and Tom's father
saw the motor fly from the testing block and shoot through the roof of
the building with a rending, crashing, and splintering sound that could
be heard for a mile.

CHAPTER IX

AFTER A SPY

Curious as it may seem, Eradicate, the oldest and certainly not the
most energetic of the party assembled in the experiment room, was the
first to recover himself and arise. Tottering to his feet he gave one
look at the testing block, whence the motor had torn itself. Then he
looked at the prostrate figures around him, none of them hurt, but all
stunned and very much startled. Then the gaze of Eradicate traveled to
the hole in the roof. It was a gaping, ragged hole, for the motor was
heavy and the roof of flimsy material. And then the colored man
exclaimed:

"Good land ob massy! Did I do dat?"

His tone was one of such startled contrition, and so tragic, that Tom
Swift, rueful as he felt over the failure of his experiment and the
danger they had all been in, could not help lau