combination of silicon and carbon now known as
carborundum, which has commercial value as an abrasive."

"I know about that," bowed Nick.

"Now, then," continued Pylotte, with an unconscious display of
enthusiasm; "while diamonds certainly have been made by artificial
means, the great difficulty has been that of producing them at a low
cost. Moissan, in my country, produced diamonds by heating charcoal and
iron to a high degree, and letting the mixture cool under enormous
pressure. He succeeded in obtaining very small crystals, or diamonds,
but the cost of production made his method impracticable from a
commercial standpoint."

"Ah! I see."

"In 1872 a chemist named Rose converted graphite into diamonds by a
similar process, but with the same result."

"The cost of production being too great?" observed Nick.

"Precisely."

"Do you think that difficulty has now been overcome?"

"I am compelled to think so, Mr. Carter," cried Pylotte, pointing to the
two diamonds on the table.

"You purchased them at a price compelling that belief?"

"Exactly."

"Then you think the man of whom you got them has discovered a way to
make such perfect artificial diamonds at a low price?"

"I certainly do, Mr. Carter."

"Have you any idea of the machinery and ingredients he might require?"
asked Nick, with a view to getting points by which to locate the diamond
plant.

Pylotte could easily inform him, and he promptly did so, following the
instructions given him by Dave Kilgore.

"He would require an electric furnace and a hydraulic press," said he.
"Also the tools for cutting the crude crystals. The ingredients used
would depend upon the process he has discovered, probably coal or
charcoal, and possibly some quantities of iron salts and sulphur."

"In brief, then, Mr. Pylotte," said Nick, pointing to the diamonds on
the table, "if those stones were made as cheaply as you think, the
diamond market offers the manufacturers of them a field for a most
gigantic swindle, does it not?"

"Indeed it does!" exclaimed Pylotte, throwing up both hands. "Enormous!
Enormous! Millions could be made by so unparalleled a fraud!"

"It opens the way, in fact, to the most colossal swindle on record?"

"Undoubtedly."

Nick glanced significantly at Chick, then abruptly rose to his feet.
That he had struck the big game which from the first he had suspected,
he now had not a doubt.

"I require no more of you at present, Mr. Pylotte," said