the office of one of his shops. "Now I'll just show you--"

"Hold on, Tom. You know I have a very poor head for figures,
even if I do help you out once in a while on some of your work.
Skip the technical details, and give me the main facts."

The two young men--Ned Newton being Tom's special chum--were
talking together over Tom's latest scheme.

It was several days after Tom's accident in the airship, when
he had been saved by the prompt action of Mr. Peterson. That
fortune-hunter, once he had the promise of Mr. Swift to invest in
his somewhat visionary plan of locating a lost opal mine near the
Panama Canal, had left the Swift homestead to arrange for fitting
out the expedition of discovery. He had tried to prevail on Tom
to accompany him, and, failing in that, tried to work on Mr.
Damon.

"Bless my watch chain!" exclaimed that odd gentleman. "I would
like to go with you first rate. But I'm so busy--so very busy--
that I can't think of it. I have simply neglected all my affairs,
chasing around the country with Tom Swift. But if Tom goes I--
ahem! I think perhaps I could manage it--ahem!"

"I thought you were busy," laughed Tom.

"Oh, well, perhaps I could get a few weeks off. But I'm not
going--no, bless my check book, I must get back to business!"

But as Mr. Damon was a retired gentleman of wealth, his