Mrs. Blake was outstretched on her back, fast asleep, and Isobel was playing with the baby under the adjoining tree, when at last the surveyors came up on the other side of the creek and ended their day's run with the establishment of a bench-mark on the top of the dike above the pool. Blake seemed as fresh as in the morning. He took a moderate drink of water dipped up in the brim of his hat, and without wakening his wife, sat down beside her to "figure up" his fieldbook. Ashton had come down to the pool panting from heat and exertion. It was the first time that he had walked more than half a mile since coming to the ranch, for he had immediately fallen into the cowboy practice of saddling a horse to go even short distances. He had his reward for his work when, having soused his hot head in the pool and drunk his fill, he came up to rest in the shade of Isobel's tree. Very considerately the baby fell asleep. To avoid disturbing him and his mother, the young couple talked in low tones and half whispers very conducive to intimacy. Ashton did his utmost to improve his opportunity. Without openly speaking his love, he allowed it to appear in his every look and intonation. The girl met the attack with banter and raillery and adroit shiftings of the conversation whenever his ardent inferences became too obvious. Yet her evasion and her teasing could not always mask her maidenly pleasure over his adoration of her loveliness, and an occasional blush betrayed to him that his wooing was not altogether unwelcome. He was in the seventh heaven when Mrs. Blake awoke from her health-giving sleep and her husband closed his fieldbook. The girl promptly dashed her suitor back to earth by dropping him for the engineer. "Mr. Blake! You can't have figured it out already?" she exclaimed. "What do you find?" "Only an 'if,' Miss Chuckie," he answered. "If water can be stored or brought by ditch to this elevation, practically all Dry Mesa can be irrigated. Our bench-mark there on the dike is more than two hundred feet above that spike we drove into your porch post." "Is that all you've found out today?" "All for today," said Blake. "I could have left this line of levels until later, but I thought I might as well get through with them." "You would not have run them if you had thought they would be useless," she stated, perceiving the point with intuitive acuteness. "I like to clean up my work as I go along," he replied. "If you wish to know, I have thought of a possible way to get water enough for the whole mesa. It depends on two 'ifs.' I shall be certain as to one of them within the next two days. The other is the question of the depth of Deep Canyon. If I had a transit, I could determine that by a vertical angle,--triangulation. As it is, I probably shall have to go down to the bottom." "Go down to the bottom of Deep Canyon?" cried the girl.