"Hardly that, either. There isn't the kind of land black diamonds grow in around here, that is, as far as I know." "Or iron?" "Scarcely iron," answered Professor Bailey, with a puzzled look at the boy. "But why do you ask me these questions? Are you thinking of turning miner instead of farmer?" with a smile. "Perhaps," said Roger, and his serious air convinced the professor that the boy had some motive in his inquiries. "You see I can't tell you all about it just now, nor why I want to know this, Professor, but I will some day. I want, most of all, to find out what, if anything, of value could be in the Cardiff hills, that would make men, or a company of capitalists, want to get possession of certain land. It might be, I suppose, coal, or iron, or gold, or something else. The question is, what is it?" "You are asking me to go ahead pretty much in the dark," objected Professor Bailey. "I'm sorry, but I'm afraid those are all the clues I can give you now," said Roger. "Well, I'll do my best to answer your puzzle," went on the teacher. "From what I've read and know of the geological formation about here, I cannot think of any mineral or other deposit that would naturally be expected in this section. But of course it might be that, unknown to any one, except a certain person, there would be a valuable mine of something beneath the surface. Some mineral or quartz, but hardly coal, nor iron, nor gold." "Perhaps it might be oil," suggested Roger. "I'm afraid not," was the reply, "though, as I said, almost anything is possible, but in this instance, not very probable. If you were to show me a certain spot, I might be able to say, with more certainty than I can now, whether or not a particular mineral would be apt to be present." "I can't take you to the place," said Roger, who was determined to guard his secret well, "because I want to keep this quiet as long as I can. But, Professor, if I brought you a sample of rocks, or minerals, or--or--something--could you tell me then?" "Possibly I could." "Then I'll see if I can't get some samples for you. But, please don't tell any one I was in to see you about this. Not that there's anything wrong," quickly added Roger, "but," and he advanced closer, "this may mean a good deal to some people, and I don't want to raise hopes and have them disappointed." "Very well," answered the Professor, a little puzzled about it all, but knowing, from Roger's frank and honest face that there could be nothing but what was right. "Very well. I'll keep quiet, you may depend on it. And, when you bring me something more definite to work on, I'll help you all I can," and, with a hearty handshake, Professor Bailey showed Roger to the door. "Now," said the boy to himself, as he walked slowly toward his uncle's house, "now to find out what they were digging for. I must get some of that stuff they brought up on the end of the drill. And I'll have to work quickly, for I think Mr. Ranquist suspects that I know."