Page:Tom Swift Among the Diamond Makers.djvu/192

182 Parker. The hidden adventurers could talk in perfect safety now, for the men in the large cave were too excited to pay much attention to them. The muttering of the thunder grew louder, and at times a particularly loud crash told that a bolt had struck somewhere in th$ vicinity of the cave.

"But, bless my watch-charm!" exclaimed Mr, Damon, "I didn't know lightning made diamonds."

"It does not—always," went on the scientist. "But great heat and pressure are necessary to create the gems. In nature this was probably obtained by prehistoric volcanic fires, and by the terrific pressure of immense rocks. It is possible to make diamonds in the laboratory of the chemist, but they are so minute as to be practically valueless.

"However, these men seem to have hit upon a new plan. They utilize the terrific heat of lightning, and the pressure which is instantaneously obtained when the bolt strikes. I am anxious to see how it is done. Look, I think they are getting ready to make the gems."

Indeed there seemed to be an air of expectancy among the diamond makers. The mixing machine had now been stopped, and, as it was more quiet in the cave, our friends, in their