"Here comes a big river boat!" cried Songbird, presently. "Let us go out and catch the rollers!" And out they swam and waited until the swells, several feet high, came rolling in. It was immense fun bobbing up and down like so many corks.
"Wish the steamers would continue to come past," said Fred. "This suits me to death."
"Here comes another pretty big boat," answered Tom. "And she is closer to shore than that other craft, so we'll get the rollers at their best."
"Don't get too close," cried Songbird. "I knew a fellow who did that once and got sucked under."
On came the river boat and was soon opposite to where the houseboat lay. She carried only a few passengers, but a very large quantity of freight.
"Here she comes!" cried Fred. "Now for some more fun."
"Don't get too close!" repeated Songbird, but Tom did not heed him and went within fifty feet of the steamboat's side. The rollers here were certainly large, but all of a sudden Tom appeared to lose interest in the sport.
"Hullo, Tom! What are you so quiet about?" sang out Dick in alarm.
"Perhaps he has a cramp," put in Sam. "Tom, are you all right?" he cried.
"Yes, I'm all right," was the answer, and then Tom swam to his brothers with all speed. The steamboat was now well on its way down the Ohio.