The men retreated well away from the steel box. Folwell threw over the lever—the same one Mr. Jenks remembered pulling. Then the man ran to the electric switch on the wall, and snapped that into place, establishing a connection.
There was a moment's pause, as Folwell ran to join the others in their place of safety. Then from without there came a most nerve-racking and terrifying crash. It seemed as if the very mountain would be rent into fragments.
Watching with eager eyes, the adventurers saw sparks flash from the steel box. Instantly it became red hot, and then glowed white and incandescent. It was almost at the melting point.
Then came comparative quiet, as the echoes of the thunder died away amid the mountain peaks.
“I guess that did the trick!” cried Folwell. “It was a terrific crash all right!”
He and the others ran forward. The steel box was now a cherry red, for it was cooling. Folwell threw back the lever, and another man disconnected the switch. There was a period of waiting until the box was cool enough to open. Then the heavy door was swung back.
With a long iron rod Folwell drew something from the retort. It was the tray which had held the white balls. But they were white no longer, for they had been turned into diamonds. From their hiding-place Tom and the others could see the flashing gems, for, in spite of the fact that the diamonds were uncut, some of them sparkled most brilliantly, due to the peculiar manner in which they were made.
“We have the secret of the diamonds!” whispered Mr. Jenks. “There must be a quart of the gems there!”
The men gathered about Folwell, uttering exclamations of delight. The diamonds were too hot to handle yet.
“That's going some!” exclaimed the chief of the diamond makers. “We have a small fortune here.”