"I thought so," went on Mr. Bobbsey. "Danny, and some of his chums, must have gone on the boat early this evening. They played about, as boys will, and some of them, either on purpose or accidentally, must have loosed the knots in the ropes before coming ashore. Then the boat just drifted away after that."
"Those boys had no right to go on our boat!" said Nan.
"No, they had not," agreed her father, "But I'm glad there was no real damage done. The watchman saw the Bluebird soon after she had drifted away from the dock, and he telephoned me. I went out in one of our tugs and soon brought her back. So you think this is Danny Rugg's cap, Bert?"
"I'm sure of it, yes, sir. Danny wanted me to take him, and some of the other boys, on the boat, but I wouldn't."
"I'm glad you remembered what I told you," spoke Mr. Bobbsey, and Bert blushed with pleasure.
"I'll give Danny his cap in the morning," Bert went on. "It may surprise him to know where he lost it."
"I don't believe you can surprise that Danny Rugg very much," said
Mrs. Bobbsey.
The next morning, when Bert took Danny's cap to school with him, and handed it to the boy who had caused so much trouble, a queer look came over Danny's face.
"Thanks," he said. "I was wondering where I left that. I guess I must have dropped it, when I was—playing football over in the fields."
"No, you dropped it on our houseboat, the Bluebird, just before you and the other fellows untied the ropes that let her go adrift," said Bert. "And you'd better keep off her after this!"