a cocoa plantation or something
of the kind?"

"Yes," replied the other moodily; "I was told that his mother owned
two-thirds of some such place along the Amazon or somewhere down
there. But let them go. It's a tremendous big country and there isn't
the least danger that we'll ever butt into them, if we _should_ decide
to take a run down."

"Still," observed the taller lad, thoughtfully, "you never can
know. I've heard travelers say that sometimes the world seems to be very
small; when you meet your next door neighbor on the top of some Swiss
mountain. Puss may know nothing about your plans and this is perhaps
only a coincidence, as they say. Since he has had such poor luck
getting to the top of our mountains around here he wants to try his hand
on those poor South American Andes."

Andy's father had been a professor in one of the colleges, who, having
taken up aeronautics, had made many balloon voyages in quest of
scientific information, so that his name had become quite famous. Then,
about a year before, he had been lost when attempting to solve the air
currents on the Panama Isthmus, where the government had thirty thousand
laborers digging the big ditch.

Nothing had ever been heard of the professor from the day he started
from the Atlantic side of the isthmus, intending to cross the mountains
and land on the Pacific beach. And it was becoming a positive mania in
the mind of Andy, who lived with his guardian, Colonel Josiah Whympers,
to some day go down there and follow in the track of his lost father, in
the hope of discovering his sad fate.

It was with this idea in mind that he had united his forces with Frank's
inventive genius and helped build the monoplane with which they had won
the race to the top of the neighboring mountain, during Old Home Week at
Bloomsbury.

And every day he was thinking more and more of what strange things the
future might have in store for him, if he ever started on that exploring
venture.

CHAPTER III.

SOMETHING ABOUT THE BIRD BOYS.

"How about coming over tonight?" asked Frank, as the boys halted at the
gate of Dr. Bird's place, where Andy had gone to get his wheel, since
he lived some little distance away.

"I'd like to first rate, Frank, because there are some things I want to
talk over with you. But I promised Colonel Josiah to get at his books
tonight and straighten them out. It'll take me all evening, I reckon."

"Oh, well," remarked Frank, "see you in th