me day Alec Peterson came to Colon
inquiring for Tom. His face showed a new delight.

"Why," cried Tom, "you look as though you had found your opal mine."

"I have!" exclaimed the fortune-hunter. "Or, rather, Tom, I think I
have you to thank for finding it for me."

"Me find it?"

"Yes. Did you hear about the top of the island-mountain you blew to
pieces?"

"We did, but--"

"That was my island!" exclaimed Mr. Peterson. "The mine was in that
mountain, but an earthquake had covered it. I should never have found
it but for you. That shot you accidentally fired ripped the mountain
apart. My men and I were fortunately at the base of it then, but we
sure thought our time had come when that shell struck. It went right
over our heads. But it did the business, all right, and opened up the
old mine. Tom, your father won't lose his money, we'll all be rich. Oh,
that was a lucky shot! I knew it was your cannon that did it."

"I'm glad of it!" answered the young inventor, heartily. "Glad for your
sake, Mr. Peterson."

"You must come and see the mine--your mine, Tom, for it never would
have been rediscovered had it not been for your giant cannon, that made
the longest shot on record, so I'm told."

"We will come, Mr. Peterson, just as soon as I close up matters here."

It did not take Tom long to do this. His type of cannon was formally
accepted as a defense for the Panama Canal, and he received a fine
contract to allow that type to be used by the government. His powder
and projectiles, too, were adopted.

Then, one day, he and Ned, with Koku and Mr. Damon, visited the scene
of the great shot. As Mr. Peterson had said, the whole top of the
mountain had been blown off by the explosive shell, opening up the old
mine. While it was not quite as rich as Mr. Peterson had glowingly
painted, still there was a fortune in it, and Mr. Swift got back a
substantial sum for his investment.

"And now for the good old U. S. A.!" cried Tom, as they got ready to go
back home. "I'm going to take a long rest, and the only thing I'm going
to invent for the next six months is a new potato slicer." But whether
Tom kept his words can be learned by reading the next volume of this
series.

"Bless my hand towel!" cried Mr. Damon. "I think you are entitled to a
rest, Tom."

"That's what I say," agreed Ned.

"I'll take care ob him--I'll take care ob Massa Tom," put in Eradicate,
as he cast a quick look at Koku. "Giants am all right fo' cannon