had been too quick for the conspirators, if such they were.
His plans and drawings were intact, and though Bower might have given a
copy to the stranger with the gold tooth, the latter did not take any
away with him. That he had some papers he wished to conceal and escape
with, seemed certain, but the splash into the mud hole had ended this.

No trace was found of Bower, and an effort Tom made to ascertain if the
man was a spy in the employ of Gale and Ware came to naught. The
machinist had come well recommended, and the firm where he was last
employed had nothing but good to say of him.

"Well, it's a mystery," decided Tom. "However, I got out of it pretty
well. Only if that gold-tooth individual shows up again he won't get
off so easily."

CHAPTER XI

A NIGHT TRIP

Taking a lesson from what had happened, Tom was very much more careful
in the following experiments on his new, silent motor. He made some
changes in his shop, and took Jackson in to help on the new machine,
thus insuring perfect secrecy as the apparatus developed.

Tom also changed the safe in which he kept his plans, for the one he
had used previous to the episode in which Bower and the stranger who
took the mud bath figured, was one the combination of which could
easily be ascertained by an expert. The new safe was more complicated,
and Tom felt that his plans, specifications, and formulae which he had
worked out were in less danger.

"I can just about figure out what happened," said Ned Newton to Tom,
when told of the circumstances. "These Universal people were provoked
because you wouldn't give them the benefit of your experience on their
flying machines, and so they sent a spy to get work with you. They,
perhaps, hoped to secure some of your ideas for their own, or they may
have had a deeper motive."

"What deeper motive could they have, Ned?"

"They might have hoped to disable you, or some of your machines, so that
you couldn't compete with them. They're unscrupulous, I hear, and will
do anything to succeed and make money. So be on your guard against
them."

"I will," Tom promised. "But I don't believe there's any more danger
now. Anyhow, I have to take some chances."

"Yes, but be as careful as you can. How is the silent motor coming on?"

"Pretty good. I've had a lot of failures, and the thing isn't so easy
as I at first imagined it would be. Noise is a funny thing, and I'm
just beginning to understand some of the laws of a