"Very well," agreed Blake, ignoring his companion's ill humor. "Kindly take back the level and get out the chain." Ashton started off without replying. Blake looked at the young man's back with a regretful, half-puzzled expression. But he quickly returned to the business in hand. He laid the level rod on a rock and inclined it at the same steep pitch as the uptilt of the gorge bottom. Over the lower end of this he held a plumb bob, and took the angle between the perpendicular line of the bob-string and the inclined line of the rod with a small protractor that he carried in his notebook. The angle measured over fifty degrees from the horizontal. Having thus determined the angle of inclination, the engineer picked a likely line of ascent and started to climb the gulch chute. He went up in rapid rushes, with the ease and surefootedness of a coolheaded, steel-muscled climber. He stopped frequently, not because of weariness or of lack of breath, but to test the structure and hardness of the rocks with a small magnifying glass and the butt of his pocket knife. At last, nearly a thousand feet up, his ascent was stopped by a sheer hundred-foot cliff. He had seen it beetling above him and knew beforehand that he could not hope to scale such a precipice; yet he clambered up to it, still examining the rock with minute care. As he walked across the waterworn shelf at the foot of the sheer cliff, his eye was caught by a wide seam of quartz in the side wall of the gulch. Going on over to the vein, he looked at it in several places through his magnifying glass. Everywhere little yellow specks showed in the semi-translucent quartz. He drew back across the gorge to examine the trend of the vein. It ran far outward and upward, and in no place was it narrower than where it disappeared under the bed of the gorge. His lips pursed in a prolonged, soundless whistle. But he did not linger. Immediately after he had estimated the visible length and dip of the seam, he began his descent. Arriving at the foot without accident, he picked up the level rod and swung away down the gulch. He saw nothing of Ashton until he had come all the distance down across the valley to the dike above the pool. His assistant was in the grove below, assiduously helping Miss Knowles to erect a tent that the girl had improvised from a tarpaulin. Genevieve and Thomas Herbert were interesting themselves in the contents of the kit-box. The two ladies had ridden up to the camp on horseback, Isobel carrying the baby. When Blake came striding down to them, the girl left Ashton and ran to meet him, her eyes beaming with affectionate welcome. "What has kept you so long?" she called. "Lafe says the gulch is absolutely unclimbable. I could have told you so, beforehand." "You are right. I tried it, but had to quit," replied Blake, engulfing her outstretched hand in his big palm.