"What's the use of bothering with it when there's an inexhaustible supply of coal in the ground?" asked Miss Nellie.

"But there isn't," answered Derrick. "This coal region only covers a limited area, and some time every bit of fuel will be taken out of it. I have heard that it is the only place in the world where anthracite has been found. Isn't it, Mrs. Halford?"

"I believe so," answered that lady; "or at least the only place in which anthracite of such fine quality as this has been discovered. Inferior grades of hard coal are mined in several other localities, and bituminous or soft coal exists almost everywhere."

From the culm pile they went to see the great pumping-engine, and the huge fans that act as lungs to the mine, constantly forcing out the foul air and compelling fresh to enter it. Then, as the day was growing warm, they did not care to go any farther, but went back towards the house to prepare for their descent into the mine.

On their way they stopped to call on Mrs. Sterling at Derrick's home, which, covered with its climbing vines, offered a pleasing contrast to the unpainted, bare-looking houses lining the village street beyond it. Here both Mrs. Halford and Miss Nellie were greatly interested in Bill Tooley, of whom they had already heard. He could not be induced to enter into conversation with them, merely answering, "yes, 'm" or "no, 'm" to their questions; but from what he said after they had gone he evidently thought their call was intended solely for him. For a long time he cherished it in his memory, and often spoke of it as a most wonderful event.

Derrick took this opportunity to secure his lunch-pail and water-can, which he slung by their chains over his shoulder. When the ladies had prepared themselves for their mine expedition, he was amused to see that Miss Nellie was similarly equipped, she having found and appropriated those belonging to her uncle. Both the ladies wore old dresses, and India-rubber boots, which they had brought with them for this very purpose, and both were provided with waterproof cloaks.

At the mouth of the slope Derrick said something through a speaking-tube that reached down into the mine. Directly the clang of a gong was heard in the breaker above them, and the great wire cable, extending its vast length between the rails of the tracks, began to move. Two minutes later a new coal-car, one of a lot that had been delivered in the mine the day before, and had not yet been used, was drawn up out of the blackness to the mouth of the slope, and stopped in front of them. Some hay had been thrown into the bottom, and as the ladies were helped in, Miss Nellie exclaimed that it looked as though they were going on a straw-ride.

Handing each of them a lighted lantern to carry, and lighting the lamp on his cap, Derrick tugged at the wire leading to the distant engine-room, and gave the signal to lower. The car at once began to move, and as they felt themselves going almost straight down into the blackness between the wet, glistening walls of the slope, and were chilled by the cold breath of the mine, the mother and daughter clung to each other apprehensively.

At first they looked back and watched the little patch of daylight at the mouth of the slope grow rapidly smaller and more indistinct, until it looked almost like a star. Then Derrick warned them that there was danger of hitting their heads against the low roof, and said they must hold them below the sides of the car. When next they lifted them they were amid the wonders of the underground world, in the great chamber at the foot of the slope. They were surrounded by a darkness that was only made the more intense at a short distance from them by the glimmering lights of a group of miners who had gathered to watch their arrival. Here Derrick left them while he ran to the stable to get his mule.

The ladies did not get out of the car, but stood in it after the cable had been cast off, and watched the loaded coal-wagons as, one at a time, they were pushed to the foot of the slope, and quickly drawn up out of sight. During this interval their eyes gradually became accustomed to the lamp-lit darkness, so that they could see much better than at first.