Supper finished, the Iron Boys went to their room, returning a few minutes later and strolling from the house as though they were going nowhere in particular. After they had put a block between themselves and the boarding house they quickened their pace. Bob was excited, but Steve was as calm and collected as if nothing unusual had occurred.

"Do you know where the superintendent lives, Steve?"

"Of course I do. I make it my business to know everything that I ought to know. 'Live and learn' is my motto. It's a good one for you to adopt, too."

"I am beginning to think you are right."

Reaching the house of the general superintendent, Rush halted. The blinds had not been drawn and, looking through the front room into the dining room beyond, the Iron Boys could see the superintendent seated at the table with his family.

"I think we had better walk up and down a few times until Mr. Penton finishes his supper," suggested Rush.

"He'll be better natured if we do, I guess," agreed Jarvis. "You have a long head on you, Steve, but the trouble with you is that you keep that fact so carefully concealed that a fellow doesn't get wise to it until it's too late."

Steve laughed softly. They had made their third trip around the block when, halting once more in front of the house, they saw that the superintendent had finished his supper. He was standing in the dining room, hat in hand, talking with a member of his family.

"Come on," called Steve, running up the walk, up the steps and ringing the bell.

"My, but you do bear out your name, the way you rush about," laughed Jarvis.

The door was opened by a servant. Steve gave his name and asked to see Mr. Penton. The latter came out into the hall a few seconds later.

"Good evening, boys. I was just on my way downtown to the post-office.

You may walk along with me and tell me what I can do for you."

"We would rather speak with you here, sir, in private," answered Steve earnestly.

"Is it so important as that, my lad?"

"It is, sir."

"Come into the parlor," said Mr. Penton, leading the way and switching on the electric lights. "State your business as briefly as possible."

The superintendent seated himself, motioning the boys to be seated also.

"By chance, I overheard a conversation between you and the mine captain at chute seventeen the other day," said Steve. "I did not want to listen, sir, but I will confess that what you said impressed me so strongly that I took a deep interest in it."

"Conversation about what?" demanded Mr. Penton rather more sharply than was his wont.

"About a shortage in the ore. You said the mine count did not agree with the figures as reported from the head office, sir."

Mr. Penton gazed shrewdly at his callers. Then he rose, and, closing the door leading into the dining room, returned to his chair.

"Well, lads," he said. "Have you come to see me on this subject?"

"Yes, sir."

"I suppose you think you might be able to solve the mystery?" This was said smilingly.

"We have solved it, sir."

"_What?_"

"I said we have solved it; at least, enough of it to make the rest comparatively easy."

"You astound me beyond words. Will you be good enough to tell me then the cause of this shortage?"

"Yes, sir; the fault lies with your tally-boards."

"That was my idea originally, but the mine captain a.s.sures me that he has careful tally-men on every board."

"I think he has very careful men there, sir. At least, they seem to me to be looking out for their own interests pretty carefully."

"You are making a most serious charge, Rush. Are you able to substantiate this?"

"I am, sir."

"Do so."

"Sub-level seventeen, to-day, as you will find by referring to your report sheet, has sixty tons to its credit."

"Wait a moment, Rush. My report sheet is in my desk in the library."

The superintendent left the room, returning with the report sheet. He ran down the page, placing his finger on a line, which he followed out to the margin.

"Your information is correct," he said, glancing up. "How do you happen to have these figures?"

"I have been watching the boards for two days."

"Indeed?"

"Yes, sir. As a matter of fact, though the tally sheet shows sixty tons as having come from number seventeen sub-level, only forty tons were actually mined there to-day."

Mr. Penton gazed at Steve Rush, who had risen and was standing before the superintendent, erect, steady-eyed and calm.

"Again, my lad, I ask you how you come to be in possession of these figures?"

"My chum, Bob, here, got the figures from the drift to-day."

"Ah, I see. You had arranged the plan?"

"Yes, sir. Bob kept a very careful tally."

"Jarvis, were you absent from sub-level number seventeen at any time during the day?"

"No, sir, excepting at meal time."

"Are you positive enough of your own tally to be willing to swear to it?"

"I am, sir."