Suddenly, Sammy raised himself on his elbow.
"What are you doing?" asked George, sleepily.
"What are you getting up for?" growled Frank.
"Listen!" said Sammy. "Don't you hear anything?"
"I don't hear anything except you," fretted Bob.
"You're dippy, I guess," complained George.
"I tell you I hear something," persisted Sammy.
His earnestness impressed his mates and they sat up.
"It's coming nearer," went on Sammy. "It sounds like a rush of horses or cattle. Put your ear close to the ground."
They did so and now all could distinctly hear what sounded like the pounding of hoofs.