alert, and he has his orders, too."

"To upset the anchor over the bow, you mean?" asked Andy.

"Just that," came Frank's reply. "If anything happens to the machinery
you'll hear a series of quick whistles from Felipe. The boat won't even
have a chance to lose headway before over plumps the big mudhook, and
we'll just take a rest out in the river until repairs can be made again
by Engineer McClintock and his assistants."

Andy looked at his chum admiringly.

"Blessed if you don't just think of everything!" he said; "and get
ready long before it happens. However do you do it, Frank?"

"Oh, it's easy, once you make up your mind," laughed the other. "I took
to it long before this new Boy Scout movement started. You know they've
got as their leading motto the words: 'Be prepared.' And there never was
a better slogan ever given to boys. Think how many things might be
avoided if we were always prepared."

"Yes, I've given the subject much thought," grumbled Andy; "but somehow
I seem to slip up when it comes to the critical time. I stay awake
eleven hours, and just when I doze off in the twelfth watch the blamed
thing happens! It's always that way, seems to me. How can a fellow stay
awake all the time, tell me that?"

"Oh, rats! There's no need of that. Just fix things so you'll be aroused
when it comes along, and be ready to turn the tables."

So they talked away into the afternoon. The engine seemed to be on its
best behavior. McClintock, the Scotch engineer, who was the only
foreigner aboard besides the boys, reported that he was beginning to
have more faith in the machinery. The work of the last twenty odd hours
had certainly been a pretty heavy tax on it and everything seemed to be
going like clockwork.

"I only hope it'll keep up, then," said Andy. "One more night is all I
ask. Then Felipe promises to have us at our journey's end, when I can
see and talk to the very man who picked up that wonderful little
parachute, with its message from the unknown valley among the cliffs. I
wish the time was here right now."

"Felipe, by the way, is taking his rest now," said Frank, after a little
time; "for he expects another night on duty. We still meet many tree
trunks sweeping down on the current. The man at the wheel has to keep on
guard constantly. Look at that tremendous one, will you, Andy? And just
notice how dense the forest is ashore around here. How any one can get
around at all beats me. I should think they'd h