Dangling like a spider on its thread, with a twist of the rope around one of his legs, Blake had gone down into the ravine, hand under hand, with the agility of a sailor. The tough leather of his chapareras prevented the rope from chafing the leg around which it slipped, and he managed with his free foot to fend himself off from the sharp-cornered ledges of the cliff side. In this he was less concerned for himself than for his level, which he carried in a sling, high up between his shoulders. He was soon safe at the lower end of the rope, on the shelf beside the bundled outfit. He waved his hat to the down-peering watchers, and climbed a few yards up the ravine, to creep in under an overhanging rock. A few moments later the loosened rope came sliding down the steep descent, the last length whipping from ledge to ledge with a velocity that made it hiss through the air. Blake was not disturbed by this proof of the cumulative speed of falling bodies. He came down and coolly set about his preparations for the descent of the gorge bottom. He unlashed the bundle and divided its contents. This done, he took a vertical measurement by going out towards the canyon along a horizontal shelf on the side wall of the gorge, until he could drop his surveying chain down the sheer precipice to a shelf almost a hundred feet below him. Unaware of Ashton's mistake and furious flight, the engineer was proceeding with his work in the expectation that he would soon be joined by his assistant. He was not disappointed. As he returned along the shelf, after entering the measurement in his notebook, Ashton came bounding and scrambling down the ravine bottom at reckless speed. He fetched up on the verge of the break, purple-faced and panting. His mouth twitched nervously and there was a wild look in his dark eyes. But Blake attributed all to the excitement and exertion of the headlong rush down the ravine. "No need for you to have hurried so, Lafe," he said. "I suppose you had to go farther around than I thought would be necessary. But I'd rather you had kept me waiting an hour than for you to have chanced spraining an ankle." "Yes, you need me in your business!" scoffed Ashton. "Your employer's business," rejoined the engineer. He straightened up from the packs that he was lashing together and gazed gravely at his scowling assistant. "See here, Mr. Ashton, this is no time for you to raise a row. We shall have quite enough else to think about from now on, until we are up again out of the canyon." "I've enough to think about--and more!" muttered Ashton. "Understand? I'm not asking anything of you for myself," said Blake. "You are doing this survey for your employer." "I'm here because of _her_!" retorted the younger man. "I'm here to make it certain that no harm is to come to _her_!"