who expressed his thanks for the
quick work of the firemen.

"Have you any idea what started the fire, Mr. Bobbsey?" asked the
chief. "Was the boathouse in use?"

"No," was the answer. "It had been closed for the winter some time
ago--in fact as soon as the carpenters finished making the changes. No
one was in it as far as I know."

"Then how do you account for this?" asked the chief, as he held out a
box partly filled with cigarettes. "I picked these up in the living
room," he went on, for the boathouse had one room carpeted, and fitted
with chairs and tables, and electric lights where the family often
spent evenings during Summer.

"You found those cigarettes in the living room of the boathouse?" asked
Mr. Bobbsey.

"I did; and the question is who was smoking?" went on the chief. "In
my opinion the end of a cigarette thrown aside, or perhaps a lighted
match dropped in some corner, started this fire. Who was smoking?"

CHAPTER XX

A CONFESSION

THE chief handed Mr. Bobbsey the half-emptied cigarette box. Mr.
Bobbsey turned it over and over in his hand, as though trying to learn
to whom it belonged.

"They are something I never use," he said. "I don't suppose we could
tell, from this, who had it?"

"No," and the chief shook his head. "It's a common kind, and a good
many of the stores sell 'em. A good many of the boys smoke 'em,
too--that's the worst of it," and he looked at Bert a bit sharply.

"Oh, you needn't be afraid for my boy!" exclaimed Mr. Bobbsey hastily.
"I have Bert's promise that he won't smoke until he's man, and perhaps
he won't want to then."

"Good!" exclaimed the chief heartily; "That's what I like to hear. But
it's as certain as guns is, and nothing more certain than them, that
some one was smoking in your boathouse, and set fire to it. And I wish
we could find out who it was."

"So do I!" exclaimed Mr. Bobbsey. "If only to teach them a lesson on
how dangerous it is to be careless. Well, I suppose we can't do
anything more," and he sighed, for half the beautiful boathouse was in
ruins.

Mr. Bobbsey and Bert were soon at home, telling the news to the folks.

Freddie's eyes opened wide in surprise as he listened to the account of
how the firemen had put out the fire.

"Oh, I wish I could have been there!" he cried. "I could have helped."

"What caused the fire?" asked Mrs. Bobbsey of her husband, when the
children had gone to bed again.

"Some boys--or some one