"That is just what I expected you to say," remarked the mine boss, quietly. "Now we will lay our first plans. I suppose you have had enough of the breaker, haven't you?"
"Indeed I have, sir."
"Very well. For a change I am going to offer you a job in the mine where I will give you a bumping-mule to drive. Your wages will be five dollars a week."
"A bumping-mule?" queried Derrick, in a tone of perplexity not unmixed with disappointment. From the preceding conversation he had expected to be intrusted with something very different from mule-driving; nor had he any idea what sort of an animal the one in question might be.
This time Mr. Jones not only smiled but laughed outright; for, from the boy's face and tone, he easily understood what was passing in his mind.
"A bumping-mule," he explained, "is the animal that draws the loaded coal-cars from the chambers, or breasts, to where they are made up into trains. These trains are then hauled by a team of mules to the foot of the slope. Then, when the empty cars are brought back, the bumping-mule distributes them to the several places where they are required. I suppose his title comes from his causing the cars to bump together as he makes them up into trains. In attending to your duties as driver of this most important mule, I can assure you that your time will be fully occupied from the minute you go into the mine until you leave it.
"I suppose," he added, with a humorous twinkle in his eyes, "that our conversation led you to think you were to be appointed 'air boss' of the mine, or placed in charge of a gang at the very least?"
"No, sir," answered Derrick, a little hesitatingly; "I ain't quite such a greeny as that. But I don't see how I can help you very much by just driving a bumping-mule."
"You can help me in two ways: first, by doing your duty so faithfully that I may be able to depend on you at all times; second, while I am in doubt as to whom I may trust, it will be of great assistance to me to know that there is at least one person constantly in the mine who will be true to the interests of his employers, and on the alert to detect any attempt to injure them."
"I hope you don't mean that I am to be a spy in the mine, sir?"