ged pontoons, we'd have
drowned most likely," replied Tom. "That would have suited the
villains who want my formula, and no one would have been the wiser as
to what caused the accident."

[Illustration: "We'd Have Been Drowned!"]

"Admitting you're right, the thing's a pretty serious mess," said Ned.
"But of course crooked people will go to long lengths for money, and if
your formula is a good one, it certainly will bring a lot of money to
someone or something."

"And that something is going to be the Swift Company!" declared Tom.

[Illustration: "It's a Pretty Serious Mess."]

"Since we can't take off in the hydroplane today," said Ned, "let's go
back to the office. I suppose it'll require some time to patch up those
holes."

Tom immediately sent for one of his skilled mechanics, a man whom he
knew to be trustworthy. He set the fellow to work welding patches over
the holes. After cautioning his employee to maintain strict silence, he
and Ned drove away.

[Illustration: He Welded Patches Over the Holes]

"Don't say anything to Dad about this," warned Tom as the two left the
field. "It would only worry him and could do no good. You and I must
work out this mess by ourselves."

After dinner that evening Tom went to his private laboratory to check
the thermostat controlling the temperature of the annealing oven in
which his batch of new glass was being slowly cooled. Then he spent some
time at his desk over certain intricate formulas. The room was in
semi-darkness, lighted only by a shaded reading lamp.

[Illustration: Tom Checked the Thermostat]

"Well, that's that," yawned the young inventor at length, locking up his
desk. "Guess I'd better put the valuable disk back in the vault before I
go home," he decided, switching on the ceiling lights and glancing
toward the corner where Koku had placed the telescope.

With a start he saw that his invention was gone!

[Illustration: His Invention Was Gone]

Quickly examining the instrument, he found that the green disk had been
jerked roughly from its clamps by someone who evidently had been in
too great a hurry to bother unscrewing the bolts which had held it in
place.

"Ho!" suddenly boomed a deep voice. Tom became aware of a commotion
outside the laboratory. "You no get 'way fum me! How you like 'nother
knock on top head?"

"Don't hit me again!" whined someone. "I won't try to escape!"

Tom flung open the door and saw his giant servant dragging a man up
t