Another hour passed, when a faint sound made Bob Somers listen with the keenest attention. Jumping to his feet, he placed his hand to his ear.
"Listen!"
Instantly the lads were all attention.
"What is it?" they cried, in unison.
"My eye! I think I hear a motor boat," exclaimed John Hackett, after several moments had passed.
"Bears, wildcats and wolves! I believe that's just what it is," chimed in Kirk Talbot, excitedly.
Nat Wingate seemed strangely agitated, as the sound gradually increased in volume. He walked nervously up and down, with his hands stuffed in his pockets.
"If it is only the 'Rambler,'" cried Bob Somers, hopefully. He brought out his field-glass, sweeping the surface of the river.
"Do you see anything?" inquired Nat, eagerly.
"No! not a thing, yet."