He stopped suddenly. A thought had struck him. He seized his lamp and oil-can and pushed ahead across the air-way and up into Conway's chamber. The mule arose with much difficulty and staggered weakly after him. A new hope had arisen in the boy's heart, an inspiration toward life had put strength into his limbs. At the breast of the chamber he set down his lamp and can, climbed up on to the shelf of coal, and began tearing out the slate and rubbish from the little opening in the wall that Conway had that day shown to him. If he could once get through into the old mine he knew that he should find pure air and--life. The opening was too small to admit his body, but that was nothing; there were tools here, and he still had strength enough to work. He dragged the drill up to the face but it was too heavy for him to handle, and the stroke he was able to make with it was wholly without effect. His work with the clumsy sledge was still less useful, and before he had struck the third blow the instrument fell from his nerveless hands. He was exhausted by the effort and lay down on the bed of coal to rest, gasping for breath. He thought if only the air current would come from the other mine into this what a blessing it would be; but, alas! the draft was the other way. The poisoned air was being drawn swiftly into the old mine, making a whistling noise as it crossed the sharp edges of the aperture. Ralph knew that very soon the strong current would bring in smoke and fouler air, and he rose to make still another effort. He went down and brought up the pick. It was worn and light and he could handle it more easily. He began picking away at the edges of coal to enlarge the opening. But the labor soon exhausted him, and he sat down with his back against the aperture to intercept the passage of air while he recovered his breath. He was soon at work again. The hope of escape put energy into his weak muscles. Once, a block as large as his two hands broke away and fell down on the other side. That was a great help. But he had to stop and rest again. Indeed, after that he had very frequently to stop and rest. The space was widening steadily, but very, very slowly. After a time he threw down the pick and passed his head through the opening, but it was not yet large enough to receive his body. The air that was now coming up the chamber was very bad, and it was blue with smoke, besides. The boy bent to his task with renewed energy; but every blow exhausted him, and he had to wait before striking another. He was chipping the coal away, though, piece by piece, inch by inch. By and by, by a stroke of rare good-fortune, a blow that drew the pick from the lad's weak hands and sent it rattling down upon the other side, loosened a large block at the top of the opening, and it fell with a crash.