"That's it! By the Great Horn Spoon, but that's it! No wonder they want to keep it secret."
"What?" asked Roger, Mr. Vanter's excitement infecting him. "What is it?"
"Well," began the surveyor, cautiously, "I wouldn't want to raise any false hopes, but, Roger, my boy, I think you have stumbled across a big discovery, or, rather, you have probably done so at the same time these two men did. And it's a mighty good thing for you and your uncle. You say he is greatly in need of money to pay off this mortgage. Does Mr. Ranquist or Mr. Dudley know about that?"
"I'm afraid they do," said Roger, thinking of how Adrian had incautiously told something of his father's affairs to the engineers that day.
"That's bad, that's bad," went on Mr. Vanter, half to himself. "Now, since they know you are on the track of their secret, they'll act promptly. Every minute is valuable. They may get your uncle to sign an agreement to-day promising to sell his land to them, and if he does so, it's as binding as if he deeded it away, if they choose to make him fulfil the contract, as, no doubt, they would do. If I had only known of this yesterday. But perhaps we can catch them yet." He looked quickly at his watch.
"But what's it all about?" asked Roger, who did not yet understand what made Mr. Vanter so excited, all over a little salt.
"It's this," replied the surveyor. "Unless I 'm very much mistaken, those men have discovered on your uncle's farm a valuable deposit of rock salt. Of its extent and worth I can only guess, but, from the actions of Mr. Ranquist, the mine must be a rich one. His object will be to secure Mr. Kimball's land, or that part of it in the spring-glade, before the fact becomes known that there is salt under the surface. Thus he can obtain, for the price of ordinary farming real estate, property that may be worth thousands and thousands of dollars."
Roger felt his breath come with a gasp.
"And it's our business to prevent this," said Mr. Vanter. "Now," he went on, "I'll tell you what we'll do."
He seemed to be thinking out a plan, and Roger waited, all impatience.