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.