Will was sure he was right in his conclusion; the camp fire belonged to Indians, and the warrior who had just vanished was one of the party, as was shown by his carelessness of movement.
Such being the case, the boy felt that he had learned all that he needed to know, and it was not prudent for him to go farther. It was now certain that a war party of Indians were in the neighbourhood, and the right thing for the boys to do was to hasten back home, so as to warn their friends.
It cannot be denied that this was a sensible decision, and Will lost no time in acting upon it.
His belief was that he was ahead of the others in learning about the red men, and he was anxious to notify Jack and George, so as to keep them from running into danger. Remembering the signal that had been agreed upon, he placed the hollow of his hands together, applied his lips to the thumbs, and gave out the whistle like that made by a steam engine, when the sound comes a long way over land and through forest.
"They will hear that," he said to himself, as he stood a minute and listened, "and will keep away from the camp. The Indians will hear it too, but they won't have any idea what it means. Hallo!"
To the surprise of Will he detected an answer to his signal. It sounded faint and far off; but you remember what I said about the trouble of knowing the point from which such a signal comes. To save his life, the lad could not have told whether it issued from the north, south, east, or west.
"That's good," he said to himself, starting back over the course by which he had advanced. "I don't think either Jack or George has got nigh enough to the camp to run any risk, and it was fortunate that I found out the truth in time to warn them."
Some minutes later, when he had made fair progress, he stopped in his walk and repeated his signal, thinking possibly that the first had been heard by only one of his companions.
"That will reach both, and start them towards the top of the ridge."
While he was listening he again caught the reply. Since he was half expecting it, he laughed.