was here, but I was mistaken."

Tom took the now harmless bomb to his stateroom, and there, after
taking the infernal machine apart, he discovered that it was not as
dangerous as he had at first believed.

The bomb contained no missiles, and though it held a quantity of
explosive, it was of a slow burning kind. Had it gone off it would have
sent out a sheet of flame that would have severely burned him and Mr.
Titus, but unless complications had set in death would not have
resulted.

"They just wanted to disable us," said the contractor. "That was their
game. Tom, who did it?"

"I don't know. Did you ever see this Professor Bumper before?"

"I never did."

"And did it strike you as curious that he should happen to be so near
at hand when the bomb fell behind us?"

"I hadn't thought of that," admitted the contractor. "Do you mean that
he might have dropped it himself?"

"Well, I wouldn't go so far as to say that," replied Tom, slowly. "But
I think it would be a good idea to find out all we can of Professor
Swyington Bumper."

"I agree with you, Tom. We'll investigate him."

Chapter XI

In the Andes

Professor Swyington Bumper seemed to live in a region all by himself.
Though he was on board the Bellaconda, he might just as well have been
in an airship, or riding along on the back of a donkey, as far as his
knowledge, or recognition, of his surroundings went. He seemed to be
thinking thoughts far, far away, and he was never without a
book--either a bound volume or a note-book. In the former he buried his
hawk-like nose, and Tom, looking over his shoulder once, saw that the
book was printed in curious characters, which, later, he learned were
Sanskrit. If he had a note-book the bald-headed professor was
continually jotting down memoranda in it.

"I can hardly think of him as a conspirator against us," said Tom to
Mr. Titus.

"After you have been in the contracting business as long as I have
you'll distrust every one," was the answer. "Waddington isn't on
board, or I'd distrust him. That Spaniard, Senor Pinto, seems to be out
of consideration, and there only remains the professor. We must watch
him."

But Professor Bumper proved to be above suspicion. Carefully guarded
inquiries made of the captain, the purser and other ships' officers,
brought out the fact that he was well known to all of them, having
traveled on the line before.

"He is making a search for something, but he won't say what