have known the way, but we don't; and if we don't look out we'll get in so deep we'll be helpless."
"Yah, let us go back," said Hans, who had not forgotten his experience in the bog hole. "A feller can't schwim in vater mit mud up to his neck alretty!"
Again they had to turn back. As they did this Dick fancied he heard a faraway cry for help.
"Did you hear that?" he asked of Tom.
"What?"
"I heard somebody call, I think."
"So did I," put in Harold Bird. "Listen!"
They listened, but the cry, or whatever it was, was not repeated. Soon they were back to the side of the houseboat once more.
"Do you think that call came from Fred or Songbird?" asked Sam.
"It might be, Sam," answered Dick. "Maybe we had better get back to the launch."
"Yes, yes, let us go back by all means!" exclaimed Harold Bird. "If your friends are in trouble we ought to aid them."
As rapidly as they could do so, they started back for the spot where the gasoline launch had been left. Once they lost their way, and got into a swamp from which it was next to impossible to get out.
"We'll have to go back!" cried Sam, after he