It was certainly a large stream, being in many places a mile broad.
Suddenly Roger detected a strange looking object beyond the horizon.
He borrowed Frank’s glass.
“I believe it is smoke,” he said.
“Smoke?”
“Yes.”
“That is queer!” said Frank. “It cannot be a camp-fire for it is too far off.”
Frank took the glass and proceeded to study the distant smoke.
A conviction dawned upon him.
“It is not a camp-fire!” he declared; “that is full fifty miles off and I believe it to be a volcano.”