and then, dismissing the matter from his mind, he busied himself about the airship.
The food and supplies had all been put aboard, and they expected to start the next morning. In order to make sure that any stones which they might succeed in getting from the diamond makers were real gems, a set of testing apparatus was taken along. Mr. Parker had had some experience in this line, and, in spite of the fact that he might make direful predictions, Tom was rather glad, after all, that the scientist was going to accompany them.
"But what is worrying me," said Mr. Damon, "is what we are going to do after we get to Phantom Mountain. What are your plans, Mr. Jenks? Will you go in, and demand your share of the diamond-making business?"
"I have a right to it, as I invested a large sum in it, and I am entitled to more than a half-share. But, of course, I can't say what I'll do until I get there. We may have to act very secretly."
"I'm inclined to think we will," said Tom. "My plan would be to gain access to the cave, if possible, and watch them at work. We might be able to discover the secret of making dia-
