r plant could
have known about them."

[Illustration: "They Left After Dinner."]

Mr. Damon could tell little more about his self-styled relatives.
After giving a description of the two men he took his leave. The boys
were rather worried about the information he had brought along.

"It's not so much the glass," said Tom, "for we don't know if it will be
a success. What bothers me is the idea of there being a traitor in the
shops. I thought we had weeded out all unscrupulous employees."

[Illustration: He Described the Two Men]

"The Apex Glass Works are located in Portville," said Ned, struck with
an idea, "fifty miles north of here. Mr. Damon's visitors claimed to
have business up state. To my mind that's more than a coincidence,
especially since the Apex people would give their back teeth to get hold
of your formula, Tom!"

[Illustration: "That's More Than Coincidence."]

CHAPTER III

AN ACCIDENT

"Oh, I think you're letting your imagination run away with you, Ned,"
grinned Tom. "I know Mr. Stern, the president of Apex, very well, and
I'm positive that he wouldn't stand for any underhanded tactics."

[Illustration: "I Know Mr. Stern," Grinned Tom]

"I hope you're right," said his business manager. "But you know better
than anyone else how unscrupulous gangs have tried to steal your
inventions. At first it was Happy Harry the tramp, and the last was
Doctor Bane. No telling how many thugs were after you and your father in
between. You'd be wise to get some extra guards."

"I think Koku is well able to handle any intruder," declared Tom
confidently. "Besides, I think you're getting excited over nothing. You
know Mr. Damon is inclined to make mountains out of molehills."

[Illustration: "Koku Is Able to Handle Anyone."]

"That's all very well," persisted his friend stubbornly, "but just
suppose Mr. Damon is right in his suspicions? It'd be too late then to
do anything about it."

"Don't worry, old man. My Chest of Secrets will hold its contents secure
against any burglar's attack. Now it's late. You'd better stay to
dinner. Afterward, if you care to and have no other date, we can talk
over some unfinished business."

[Illustration: The Chest Would Guard the Secrets]

"Thanks, Tom. I'll be glad to spend the evening with you."

Locking up the laboratory, the two boys walked leisurely through the
warm June twilight toward the big white house. Low in the sky hung the
silvery crescent of the new