o have considerable difficulty in keeping Joe from
guessing the truth.

"Well, perhaps that's so," agreed the lad. "But maybe Mr. Stanton has
some clues."

The lighthouse keeper came downstairs at this moment with a bundle of
papers in his hand.

"Here is all I found," he said. "It isn't much, but among the things he
left behind is the letter you wrote," and he extended to Joe the missive
the lad had penned in such hope at Flagstaff.

"Poor Dad," murmured Joe. "I wonder if he will ever get this?"

Together he and Blake looked over the documents. As the keeper had said,
there was not much. Some memoranda, evidently made as different clues
came to him; paid bills, some business letters, a few notes, and that
was all.

"What's this?" exclaimed Blake, as he read one letter. "It seems to be
from some shipping agent in San Francisco, saying he can place--why,
Joe, it's to your father, and it says he can have a place as mate any
time he wants it. Was he a sailor?" he asked, eagerly, turning to the
keeper.

"So I understood."

"Then this is the very thing we're looking for!" cried Blake. "Look, it
is dated only a short time before he left. I see now," and he gave the
lighthouse keeper a peculiar look, when Joe was not glancing in his
direction. "Mr. Duncan got word that he could ship as a mate, and he
left in a hurry."

"Maybe so," assented Mr. Stanton.

"Perhaps he had some new clue about you, Joe, or possibly about your
sister," suggested Blake, hoping his chum would come to take this view.

"Maybe," assented Joe. "But it's queer he didn't leave some word, or
tell someone he was going."

"He may not have had time," went on Blake. "Vessels have to sail in a
hurry, lots of times, and he may have had to act quickly."

"It's possible," admitted the keeper.

"Then I'll tell you what we'll do," continued Blake. "We'll go to San
Francisco the first chance we get, and see this shipping agent. He may
be able to put us on the right track."

"I guess it's the only thing to do," agreed Joe, in despondent tones.
"Poor Dad! I nearly found him, and then I lost him again."

They looked over the other papers. None offered as promising a clue as
did the agent's letter, and this Joe took with him, also his own to his
father.

"Maybe I'll get a chance to deliver it to him myself," he said, with a
smile that had little of hope in it.

There was nothing more to be learned at the lighthouse. The boys left,
after thanking th