em. By this time another ring was rising. It,
like the first one he had seen, was followed by two others.

"It's a signal!" announced Butler quietly. "Now what can it mean?"

"It means trouble for us," spoke up Stacy. "I can feel it in my bones."

"Who would desire to make trouble for us here?" demanded the Professor.

"I don't know," replied Tad. "I don't believe that smoke has anything to
do with us. It must be an Indian signal."

"No Indian," grunted Anvik. "Him white man smoke."

"How do you know?" questioned the Professor sharply.

"Me know."

"Then perhaps you may be able to tell us whose smoke it is?"

"Him white man. Mebby same man, mebby not. White man all same. Him call
other white man. Him say some along, by jink."

"Let's make a smoke and answer him," suggested Ned eagerly. "That would
be a joke on him, whoever he is."

Tad said "no," and said it emphatically.

"No make smoke," agreed the Indian. "Smoke want white man off
yonder"--pointing to the southwest.

"How do you know that?" asked Butler.

"Smoke him go that way. Want us, smoke him go this way."

"I never knew that before," reflected Tad. "You see, boys, they make
these signal smokes by building a smudge, then holding a blanket over
the smudge. By removing the blanket and replacing it they can make a
definite number of smokes, long smokes or short smokes; in fact, they
can almost make words, like the telegraph. It is a wonderful thing. I
wouldn't be surprised if those signals could be made out twenty or
thirty miles away, if one had eyes sharp enough to detect them."

"But what are they signaling for?" demanded Stacy.

"I don't know. Anvik says it is white men. I can't tell you anything
about that. Smoke is just smoke to me. They are communicating with
someone. We shan't see them, as they must be all of ten miles away."

"Fifteen," corrected the guide.

"That shows how poorly a novice judges distances in this country,"
nodded Butler. "They may see our fire to-night. If they are friendly we
shall no doubt meet them. If they are not, we may never see a sign of
them again. That is the way I reason it out."

Anvik grunted and nodded. The Indian understood a great deal more of
what was being said than one would have supposed. In fact, to look at
him one would not think he had even heard anything of what was being
said about him. He was the silent, impassive-faced stoic of his race.

After darkness had set in the boys scanned the mou