As he did so, he heard a faint moan, and hastening in the direction from whence it came, found Bull-dog, who, unable to spring high enough to escape the passing rocks, had been swept along and partially buried under the debris that followed. "My boy, are you hurt?" asked Houston, bending over him in the darkness, and removing as fast as possible the mass of crushed and broken rock under which he lay. "Not much, I guess," replied the little, familiar voice, in tones that tried to be brave and cheery, but which quivered with pain, "I tried to hold on, Mister Houston, but that big rock was a little too much fer me." As Houston at last freed him, the little fellow tried to rise, but sank quickly back, with an involuntary cry: "I guess I'm done fer--Mister Houston," he gasped faintly, "but I don't care--if you only--get out safe." The smoke and gases were now pouring down the shaft, and Houston realized that there was no time to be lost. Very tenderly he lifted the little form in his arms, and began, as rapidly as possible, the descent of the shaft, groping his way amid the rocks, toward the cut leading to the tunnels, through which he hoped to escape. The motion roused Bull-dog who had fainted. "Mister Houston," he cried, "don't mind me--I wanted to save you, and I guess you can make it yet, if you hurry and don't bother with me; I won't mind bein' left here, 'cause I'll know then that you're safe." "Don't you worry, my boy," replied Houston, and his own voice trembled, "we'll reach daylight all right, but we'll reach it together; I'll never leave you." There was no reply except a contented, confiding nestling of the little head against Houston's shoulder; then, as a second explosion thundered above them, jarring the foundations of the rocks once more, he murmured drowsily, "There she goes again," and sank into unconsciousness. The smoke was now so stifling that Houston was obliged to go upon his hands and knees, carrying Bull-dog in one arm; his progress was necessarily slow, but to his great joy he succeeded in finding the cut leading to tunnel No. 3; then, to his horror, he discovered that the entrance was blocked by a mass of earth and loose rock which had caved in. Laying Bull-dog carefully down, he examined the obstruction, and found there was a small opening at the top, and that the mass was of such a character that it could easily be removed with pick and shovel, but he had nothing. With desperate energy, he began tearing away the earth and rocks with his hands, then to his intense relief, after a few moments' work, he heard voices on the other side. Houston listened; it was Jack and Mike, who, having waited for him in the tunnel, expecting him to join them immediately, had become alarmed at his non-appearance, and were returning with their picks and shovels, which they had taken out with them, calling him and searching for him.