Early the next morning the boys went over the mine with an assistant engineer. He gave them a long talk on tracks, Steve asking many questions as they went along. That afternoon the Iron Boys began their work, having laid out a certain number of levels that were to be visited each day. As Mr. Penton had told them, their new position took them to nearly every part of the mine, from the lowest working level to the tram tracks on the surface and far up on the trestle. By the time that they had been at their new work for several months, each lad had proved that he was worthy of the confidence placed in him by the general superintendent. Steve had been figuring on a problem in his department for a long time, and one day he went to the superintendent with it, or rather to learn whether the problem were a problem at all. "I want to ask, Mr. Penton, if the expense of keeping up your motors that draw the dump cars in the mines is very great." "I should say it is," was the prompt answer. "You see, they draw very heavy loads. Those cars of ore are not light." "I am well aware of that. You will remember that I had a load dropped on me once," smiled Steve. "We wear out, I should say, on an average of six motors a year. That runs into money. And the repairs on them, in the meantime, are very expensive." "Would any arrangement that would tend to lessen the strain on the motors be of advantage to the company?" "That is self-evident. Of course it would. What is more, relieving the cars of the strain to which they are subjected would save a few thousand dollars a year. Have you something in mind?" Mr. Penton smiled good-naturedly on the young man who was standing before him. "Yes, sir, I have a plan by which I think you ought to be able to save your electric motors considerably and at the same time make greater speed in getting ore to the chutes." "If you have a practical plan for doing that you will have accomplished a great deal, young man. What is your plan?" "Well, sir, it is an engineering problem. Not being an engineer, I perhaps shall not be able to overcome all the difficulties in the way. I can tell you, though, what I think would help." "Do so." "I find that in most of the levels there is a considerable up grade to the chutes where the tram cars are dumped." "That is a fact." "Would it not be much better to have the loaded cars run down grade to the chutes? Then they would go back up the grade empty," suggested Steve half hesitatingly. Mr. Penton gazed at him quizzically. "Do you know, my boy, you have made a suggestion that even the keenest of our engineers evidently never have thought of?" "I am glad if I have suggested something worth while," said Steve, with a pleased smile. "But how do you propose to go about it? The levels are made and the tracks are laid to fit the conformation. How are you going to get over that condition?" asked the superintendent, with a twinkle in his eyes. "As I told you, I am not an engineer."