"Well, what do you think of that?" muttered Bob. "Is that the plank that held up the post?"

"Judging from the mark in the middle, I should say it was. Bring the old post over here."

Bob did so, and at Steve's direction placed the end of the post on the broken piece of plank. The post fitted the faint outline perfectly.

"Well, what do you think of that?" breathed Jarvis.

"That somebody has tried to make a clean job of getting me out of the way. That plank was sawed partly through so that it might not break at once, but would do so when any extra weight was thrown upon it. We must find those other pieces, Bob. Look about. I guess we'll have something to report to Mr. Penton."

Ill.u.s.tration: Steve Triumphantly Held Up a Saw.

"Shall we say who did it?"

"We can't really say. We may have our suspicions, but unless we get more evidence we shall have to let it go as it is. I have some facts in my possession that may help us, though."

Steve got down on his hands and knees and began going over the floor with great thoroughness. He was keen and alert and his eyes glowed with resolute purpose.

"Here's one of the broken pieces," cried Bob.

"Good. See if you can find the other. We shall have our case complete in a few minutes if we keep on having such good luck."

But one piece was all that Bob was able to find, the other no doubt having been thrown into the shaft. The one found was lying at the edge of the platform near its end.

"I guess there is nothing more here for us to do," decided the lad finally. "We will take our evidence and go to Mr. Penton."

"We haven't enough to hang a dead cat on."

Steve smiled.

"We shall see," he answered. "You tuck the saw under your coat and I will carry the boards."

Entering the first cage that stopped at this level, the boys were quickly conveyed to the surface. Steve asked the cage-tender at the mouth of the shaft if he had seen the superintendent about the shaft, and was informed that Mr. Penton was at that moment in the dry house. He was no doubt dressing to go down in the mine.

The boys hurried to the dry house, finding Mr. Penton talking with one of the time-checkers.

"May we see you alone, sir?" asked Steve.

"Certainly. Come into my dressing room. You have some news, eh?" queried the superintendent, flashing a keen glance at them.

"We think we have, sir."

After entering the dressing room, Mr. Penton nodded for them to proceed.

Steve went right to the point.

"We have been down in the skip shaft."

"On seventeen platform?"

"Yes, sir."

"Did you discover anything of consequence?"

"Mr. Jarvis has a saw that we found there. It belongs to one of the timber-men, and was stolen from him the day before the accident."

The superintendent p.r.i.c.ked up his ears at this.

"I learned that fact this morning. He doesn't know that we have the saw.

We found it where it had evidently been thrown by the person who used it. And here is something else, sir."

Steve laid the broken pieces of plank on a table. Mr. Penton picked them up, turning them over in his hands, pausing when he discovered the marks of the saw, then he glanced at Steve.

"What is this?"

"It is the support that rested under the post holding up the old trap,"

answered the lad.

"Then--then----"

"Someone had sawed it partly through, so the support would give way and let someone else down. I happened to be the one who was let down."

The smile vanished from the eyes of the general superintendent and the lines of his face hardened perceptibly.

"How do you know this piece supported the post?"

"You will find the mark of the post on it. We fitted the post to the mark to make sure. Whoever did the job, entered the skip shaft from sub-level seventeen. I am sure of this, because I found fresh mud on the rungs of the ladder. No one is supposed to go down there, is he, sir?"

"No; no one does go down there. This is very serious. Why did not my men discover all these things?"

"I guess they did not look very sharply. The evidence was there to be found if one looked hard enough."

"Rush, you suspect someone?" said Mr. Penton sharply. "Whom do you suspect?"

"Perhaps this may answer the question," answered the lad, laying on the table a bra.s.s time check about the size of a half dollar.

"Where--where did you get this?"

"On the platform where the job was done, sir," answered Steve, directing a steady gaze at the stern face of the superintendent.

CHAPTER XVII

THEIR FIRST PROMOTION

"Wait a minute," said Mr. Penton, hurrying across the hall to the office of the time-keepers.

He was gone but a few moments and when he returned there was a look on his face that Steve had never seen there before. It was a look that meant trouble for someone. The superintendent sat down, gazing out of the window at the towering shaft of the Cousin Jack Mine.