The boat continued to make good headway against the current, though at this season of the year the Magdalena is bank full with the summer rains, which fall almost every afternoon in a deluge.
A searchlight sent a dazzling shaft of light far ahead on the troubled surface of the booming flood. This was an absolute necessity, for otherwise it would have been too dangerous bucking against that tide; laden as the river was with floating tree trunks of gigantic size, that had been swept from their resting-places in the lowlands above.
Once Frank had seen a wild animal crouched on one of these great logs. The boat passed so very close to the floating refuge of the beast that ere darkness claimed the strange craft with its stranger cargo, Frank had been able to see the tawny hide of the crouching beast, and note the quick, jerky motion of its long tail.
Upon hurrying to the pilot house and making inquiries of Felipe he learned that, just as he suspected, the animal was a jaguar, the most feared inhabitant of the tropical forests away off at the headwaters of the Magdalena and Orinoco rivers.
There was a spice of peril hovering over the progress of the little boat during every hour of that night. It might come in the sudden leap of a wild animal, that judged any port would be better than a floating log. Then there was a chance of their running afoul of a monster derelict, in the shape of a drifting snag, that might punch a hole in their bow, and bring about trouble.
On top of all was this unseen peril from the revolutionists, who were making the Magdalena country the center of their renewed activity, for some reason or other, and had their minds set on securing the first aeroplane ever known to be in Colombia.
The time passed away. When three hours had really gone, and all seemed well, Frank awoke his chum. Generous to a fault, he might have held out much longer, for he did not feel exhausted; but Andy, who knew him like a book, had made him promise faithfully, on his word of honor, that he would arouse him at exactly the time agreed upon.
"Everything lovely, and the goose hangs high!" Frank said, as the other joined him presently on deck.
"That's good," replied Andy. "And as it is now one o'clock, with no trouble doing, looks good to me that we'll pull through the night without a mess."
"You never can tell," observed the careful Frank. "And the only way to do is to act just as if you felt positive something was bound to crop up."