we sha'n't have any prying eyes."

"I see! Well, Tom, I'll go with you. Fortunately I didn't tell my wife
where I was going when I started out this afternoon, so she won't worry
until after it's over, and then it won't hurt her. I'm ready any time
you are."

"Good! Stay to dinner and I'll show you what I've made. Then we'll take
a flight after dark."

This suited the eccentric man, and a little later, after he had eaten
one of Mrs. Baggert's best meals, including rice pudding, of which he
was very fond, Mr. Damon accompanied Tom to one of the big hangars
where the new aeroplane had been set up.

"So that's the Air Scout, is it, Tom?" asked Mr. Damon, as he viewed
the machine.

"Yes, that's the girl. 'Air Scout' is as good a name as any, until I
see what she'll do."

"It doesn't look different from one of your regular craft of the skies,
Tom."

"No, she isn't. The main difference is here," and Tom showed his friend
where a peculiar apparatus had been attached to the motor. This was the
silencer--the whole secret of the invention, so to speak.

To Mr. Damon it seemed to consist of an amazing collection of pipes,
valves, baffle-plates, chambers, cylinders and reducers, which took the
hot exhaust gases as they came from the motor and "ate them up," as he
expressed it.

"The cylinders, too, and the spark plugs are differently arranged in
the motor itself, if you could see them," said Tom to his friend. "But
the main work of cutting down the noise is done right here," and he put
his hand on the steel case attached to the motor, the case containing
the apparatus already briefly described.

"Well, I'm ready when you are, Tom," said Mr. Damon.

"We'll go as soon as it's dark," was the reply. "But first I'll give
you a demonstration. Start the motor, Jackson!" Tom called to his chief
helper.

Mr. Damon had ridden in aeroplanes before, and had stood near when Tom
started them; so he was prepared for a great rush of air as the
propellers whirled about, and for deafening explosions from the engine.

The big blades, of new construction, were turned until the gas in the
cylinders was sufficiently compressed. Then Jackson stepped back out of
danger while Tom threw over the switch.

"Contact!" cried the young inventor.

Jackson gave the blades a quarter pull, and, a moment later, as he
leaped back out of the way, they began to revolve with the swiftness of
light. There was the familiar rush of air as the wooden wing