The beetling walls narrowed in until the gash was scarcely fifteen feet wide. Further progress was barred by a smooth wall which rose sheer in front of him. * * * * * Kirby did not know how many seconds passed before he made out through the gloom that the wall was man-made and carved with the same symbols of Sun, Moon, and Feathered Serpent, which ornamented the cylinder of gold. But when he did realize at last, the shout with which he expressed his feeling was anything but a groan. It simply meant that the skeleton which once had been a man, had almost surely found the golden cylinder beyond the wall and not in the canyon. And if the dead man had passed that smooth, carved barrier, another man could do it! Kirby jumped forward, began to search in the darkness for some hidden entrance. Minute after minute passed. He gave another cry. He saw a long, upright crack in the stone surface, and a quick push of his hands made the stones in front of him give almost an inch. All at once his shoulder was planted, and behind that square shoulder was straining all the muscle of his two hundred pound body. The result was all that he desired. When he ceased pushing, a slab of rock gaped wide before him, giving entrance to a pitch dark tunnel. For a moment he held the portal back, then, releasing his pressure, he stepped into the dark passage. By the time a ponderous grating of rocks assured him that the door had swung shut of its own weight, he had produced matches and struck a light. * * * * * The puny flame showed him a curving passage hewn smoothly through the heart of bedrock. Before the flare died he walked twenty feet, and as another match burned to his fingers, he found the right hand curve of the passage giving way to a left hand twist. After that he dared use no more of his precious matches. But just when the darkness was beginning to wear badly on his nerves, he uttered a low cry. As he increased his rapid walk to a run, the faint light he had suddenly seen ahead of him grew until it became a circular flare of daylight which marked the tunnel's end. Out of the passage Kirby strode with shoulders square and head up, his cool, level, practical blue eyes wide with wonder. Out of the tunnel he strode into the valley of the perfumed geyser. "God above!" The words were vibrant with hoarse reverence. He saw the sunlight of a cliff-surrounded diminutive Garden of Eden. He saw a vale of flowering grass, of palms and live oaks, saw patches of lilies so huge as to transcend belief, and dizzying clumps of tree cactus almost as tall as the palms themselves. What was more, he saw in the center of this upland, cliff-guarded valley, a gaping black orifice which every faculty of judgment told him was the mouth of the geyser of perfume. And beside it, outstretched on a smooth sheet of rock which glistened as though coated with a layer of clear, sparkling glass, he saw--