Steve was studying the face of the Italian keenly. This Mr. Carrhart observed and nodded significantly to Superintendent Penton. But Steve could not make up his mind that Dominick was in any way to blame for what had barely missed being a great disaster.

Both lads were puzzled. They could not understand it at all.

"Perhaps a spark dropped from the trolley wire, thus firing the bag,"

suggested the superintendent, after briefly turning the question over in his mind.

"That is a plausible explanation," said Mr. Carrhart, "and for want of a better one we shall have to let it go at that. Yes, I think that must be the explanation."

The party decided that they had seen enough of the Cousin Jack for one day. Some of the officials were more anxious to get out of the place than they cared to admit. They were not used to having their luncheons interrupted by fifty-pound sacks of dynamite catching fire.

Each, before leaving, stepped up and shook hands with the Iron Boys.

"I want to see you before I leave the range," said Mr. Carrhart as he bade Steve good-bye.

"Yes, sir," answered the boy, touching his hat, as he stepped to one side to permit the visitors to pa.s.s around the chute.

"We must do something for those boys," said Mr. Cary to the president.

"Yes," agreed Mr. Carrhart.

"They are doing something for themselves, gentlemen," returned the superintendent. "They are not lads to need much help. They are the kind who carve out their own futures."

"Well, they've gone," announced Bob, stamping the dirt from his shoes.

"What do you think of it?"

"Of the fire--the burning bag, you mean?"

"Yes."

"I think it was a mighty queer occurrence."

"So do I," agreed Jarvis, "and it's my opinion that it will bear looking into."

"Where's Dominick?"

"He sneaked away when the others left. But he is of no use to us. He knows nothing about this affair, beyond what we all saw. We must look beyond him for the cause of the fire. Well, I'm off."

The lads separated for the time being and went off about their duties.

But the thought of the fired bag kept recurring to Steve Rush. He turned the matter over and over in his mind, yet without being able to reach any definite conclusion regarding it.

"I wish I knew," he mused. "It is not my business, however, to inquire into the affair unless I have orders to do so."

He was to receive his orders sooner than he imagined, and his investigations were eventually to develop some startling facts concerning conditions in the Cousin Jack Mine.

CHAPTER XX

INTO A BLACK GULF

While the Iron Boys were trudging through the mine, completing their weary rounds of miles with their eyes fixed keenly on the tracks, a meeting had been called at the office of the superintendent. All of the gentlemen who comprised the party of visitors at the mine were at the meeting.

Maps of the mines on the range were spread out on the table before them, and they were going over and discussing these maps in detail. Business was transacted with a speed that would have made most of the business men in that remote region dizzy headed.

Having disposed of the matters before them, the conversation turned to their recent narrow escape in the Cousin Jack Mine. The visitors were fully convinced now that the fire had been caused by a spark from the trolley wire, and Superintendent Penton, if he thought otherwise, did not say so. He had made up his mind, however, to push his inquiry a little further. He wanted to make sure that the suggestion was the correct one.

From the subject of the fired bag the men turned to a discussion of Steve Rush and Bob Jarvis. This ended in Mr. Cary's making a proposition. After a little discussion it was put in the form of a motion and pa.s.sed with enthusiasm.

Of all of this, of course, the lads tramping along the levels far underground knew nothing. It was destined to come as a great surprise to them when they learned of the action taken by the officials of the company in the interest of the two plucky boys.

That night the officers boarded their private car and went on to visit other of the company's mines further up the range. Early on the following forenoon Superintendent Penton visited his own mine, and while there looked up Steve Rush.

The superintendent asked Steve what he thought about the theory of a spark from the wire having fired the dynamite bag.

"I don't take any stock in it," answered the boy promptly. "Do you, sir?"

"I have had my doubts, but how else could it have started?"

"I will answer that question by showing you that it could not have started from a wire spark. The fire started on the underside of the bag.

Did you notice that?"

"No; it had spread over the bag when I caught sight of it. But I was reasonably certain there was more to it than we imagined when you asked Dominick if he met anyone in the level just before reaching the chutes."

Steve nodded reflectively.

"What do you infer from the fire starting on the under side of the dynamite bag?"

"That someone had either accidentally or by design shoved a candle under the bag while Dominick was carrying it. That is the only way I can see that the fire might have started."

"I think you are right about that. But it surely was an accident. No one would be willing to take such terrible chances. Why, it might have blown everyone up within a wide radius."

"Yes, it would have done so."

"And yet you were down on your knees, with your nose right over the stuff, as if it were so much clay. I have steady nerves myself, but I don't believe I should have had the pluck to do that. At least, I know I should have turned my head away."

Steve laughed.

"I am afraid that would not have helped you much if the stuff had gone off."

"Rush, if you suspect anything keep your eyes open; that's all I have to say. What you don't see will not be worth the seeing."

"Very well, sir; I will do as you request, but I have not much hope of getting at the truth."

"I'll risk that. I am going to the lower level. There is some difficulty with the pumps there, the engineer tells me," said the superintendent, proceeding on his way.