young inventor understood. Mr. Swift was getting rather along in age,
and his long years of brain work had made him nervous. He had a great
fear of Morse and his gang, for they had made much trouble for him in
the past. Tom appreciated his chum's hesitancy, and guessed that Ned
had something to say that he did not want Mr. Swift to hear.

"Come on up to my room, Ned. I've got something I want to show you,"
exclaimed Tom, after a pause.

The two lads left the room, Tom glancing apprehensively at his father.
But Mr. Swift was so engrossed, together with the aeronaut, in making
some calculations regarding wind pressure, that it is doubtful if
either of the men were aware that the boys had gone.

"Now what is it, Ned?" demanded our hero, when they were safe in his
apartment. "Something's up. I can tell by your manner. What is it?"

"Maybe it's nothing at all," went on his chum. "If I had known, though
that those men had gotten out of jail, I would have paid more
attention to what I saw to-night, as I was leaving the bank to come
here."

"What did you see?" demanded Tom, and his manner, which had been calm,
became somewhat excited.

"Well, you know I've been helping the payingteller straighten up his
books," went on the young bank employee, "and when I came out tonight,
after working for several hours, I was glad enough to hurry away from
the `slave-den,' as I call it. I almost ran up the street, not looking
where I was going, when, just as I turned the corner, I bumped into a