ave to keep their
machetes busy all the time cutting the matted vines away."

"I understand they do," the other went on. "And I rather guess that
there's hardly a country under the sun where an aeroplane would be of
more real benefit than right here in the tropics. Think of avoiding all
that tangle--of floating along, a mile a minute if you wanted, far above
the tree tops and away from all such a muss."

"You're right," agreed Frank, fervently. "And it's the only way any one
could ever hope to discover this strange prison of your father. From a
distance of a thousand feet we can have a big range of vision. With our
good glass it will not be hard to discover the cliffs, if only we figure
out in which direction we can have the best chance. And I think I've got
a scheme ready to manage that."

"I depend on you to do it," said Andy. "Alone by myself I would simply
despair of ever learning anything worth while. But while you are along I
just feel that we're going to succeed."

"I ought to thank you for saying that, but I won't," Frank
declared. "Because it makes me tremble for my reputation as a prophet."

"But you have seen nothing to make you less confident, I hope?" cried
the other.

"To be sure I haven't," replied Frank, readily enough. "On the other
hand, I ought to feel better satisfied than ever, because we've managed
to outwit every cause for trouble that has cropped up this far. We'll
get through this coming night without accident, because we're ready for
anything. Then, when another day dawns, we'll haul in at Magangua, to
hunt Jose Mendoza up and hear what he can tell us about the parachute
that fell among his cocoa trees."

"Hark! what ails the men forward?" exclaimed Andy just then.

They sprang to their feet and rushed to where they could see what was
going on.

"Perhaps a mutiny!" exclaimed Frank, who could not tell what queer thing
was ever going to happen down in this land, the people of which were so
different from all whom he had ever known before.

Andy uttered a low cry of alarm and began to fumble for the revolver
Colonel Josiah had made him promise to always carry on his person, once
they reached the country of revolutions.

The first sight they obtained told them that something unusual had
indeed happened. A number of the native crew were in range of their
vision, but every man had fallen flat on his face and seemed to be
cowering there as if afraid.

"What in the dickens is it?" gasped