The others agreed, for there was a possibility of finding almost anything in this out-of-the-way tributary.
“But we must not stray too far from the Tapauá,” warned Professor Bigelow, as the crew turned the boats in that direction.
For the first hour the country remained much the same. Then they reached a region where rocky crags protruded out from the shore, making it necessary for the crew to be doubly careful in guiding the boats. And with this danger came the possibility of another, for the current was growing stronger. A terrific rapids could be only a short distance downstream. At last, much to the surprise of all, they came to another river, running at right angles to the one they were on.
A thought struck Bob.
“Do you remember that tributary we passed yesterday that formed a V with the Tapauá?” he asked. “Well, I’ll bet this is it. It runs almost parallel with the Tapauá, and we’ve come upon it by taking this course that runs at right angles.”
“By George, you may be right,” agreed Mr. Lewis, suddenly grasping the meaning. “What say we turn down it and see if Bob isn’t right? If he is we’ll gradually fork over to the Tapauá and be where we were yesterday afternoon.”
The others did not object, for they were curious to know whether or not Bob was right.
The current gradually grew stronger, carrying the boats ahead at a much swifter pace. Although this afforded the crew a chance to rest, it worried the explorers, for it was plain that a rapids was somewhere ahead.
They paddled on, however, confident that they were not near enough to be in danger.