" assented Tom. "Though who would have an
object in that I can't understand. He had no enemies, as far as is
known, and his business affairs were in excellent shape. Unless, as I
said, the persons who ran him down are, through fear, keeping him
hidden until he recovers, I can't imagine what has become of him."

"Well, it certainly is a puzzle," said Ned. And Tom agreed with his
chum.

It was about a week after the disappearance of Mr. Nestor that Mr.
Damon came over to see Tom.

"Bless my shoe laces, Tom!" exclaimed the eccentric man, "but you are
as busy as ever." For he found the young inventor in the experiment
shop, surrounded by a mass of papers and all sorts of mechanical
devices.

"Yes, I'm working a little," said Tom. "But you are just in time. Come
on out, I want to introduce you to Silent Sam."

"'Silent Sam!'" exclaimed Mr. Damon. "Have you been taking a new trip
to the Land of Wonders? Have you brought back some new kind of servant?"

"Not exactly a servant," said Tom with a laugh, "though I hope Silent
Sam will serve me well."

"'Silent Sam?' What does it mean? Is that a joke?" asked the puzzled
Mr. Damon.

"I hope it doesn't turn out a joke," replied Tom. "But come on, I'll
introduce you to him, Mr. Damon."

He led the way to one of the big hangars where his various machines of
the air were housed. On the way Mr. Damon asked about news of Mr.
Nestor, but was told there was none.

Tom Swift opened the big, swinging doors and pulled aside an enveloping
canvas curtain. There stood revealed a big aeroplane, of somewhat new
pattern, the wings gleaming like silver from the varnish that had been
applied. In shape it was not unlike the machines already in use, except
that the propellers were of somewhat different design.

The engine was mounted in front, and even with his slight knowledge of
mechanics Mr. Damon could tell that it was exceedingly powerful. But it
was certain devices attached to the engine that attracted his
attention, for they were totally different from any on any other
aeroplane, though they bore some resemblance to apparatus on the plane
in which Tom and the eccentric man had made the night flight.

"Is this your new machine, Tom?" asked Mr. Damon.

"Yes."

"Well, I don't see anything of that fellow you spoke of--Silent Sam."

"This is Silent Sam," returned Tom, with a laugh. "I've named my new
noiseless aeroplane--my Air Scout--I've named that Silent Sam. Wait
until you hear