In a little hollow, about three hundred feet away from the spring which burst out of the side hill, and which served to furnish drinking water for Mr. Kimball's house, the two men came to a halt. Roger hid himself behind a big stone, somewhat above them, to watch. Mr. Ranquist drew from his valise a number of pieces of metal, which he screwed together until he had a rod about a yard long. Then, with a hammer, he proceeded to drive this downward into the earth. When it had been forced almost out of sight he screwed another section on from above and drove this down, and so on, until he had sent the slender steel rod to a depth of twenty feet into the earth. Roger noticed that the blows of the hammer, as they struck, produced no sound beyond a dull thud, which, close as he was, he could scarcely hear. "He must have rubber on the hammer," said the boy, "or something to deaden the blows. He's afraid some one will hear him. I wonder what in the world they can be up to? I must get a little nearer, so I can listen to what they are saying." He was a little fearful about advancing any farther as he could not tell but that the sound of his movements might come to the ears of the men, now they had stopped walking and could hear better. He looked to see if he could approach under cover, and then he spied a fallen log, extending down hill, toward the centre of the little glade, in which the men were at work on their mysterious errand. The farther end of the tree trunk was up against a large bowlder, behind which Roger might lie hidden, as secure as he was in the position he had first selected, if he could but reach it unobserved, and he thought he might by crawling along under the protecting shadow of the log. So with this end in view, he proceeded to act. He stretched out on his stomach, regardless of his clothes, like a big snake, and then he began to slowly wriggle toward the men. It was not easy work, as he dared not raise himself more than a few inches from the ground without the danger of being seen above the log. Along the dried leaves and grass he went, pausing every few minutes to peep cautiously over his screen to see if the men were aware of his presence. They seemed all unsuspicious that they were being watched by a sharp-eyed lad, and continued to drive the rod deeper into the earth. At length, after about five minutes of cautious crawling, Roger reached the rock, and he curled himself up behind it with a sigh of satisfaction. He was now within sixty feet of the men and could easily hear all they said, unless they spoke in whispers, which they were not likely to do. But the boy seemed to have had his trouble for his pains, for Mr. Dudley and Mr. Ranquist were not saying a word to each other. They were intent on the work, and Roger was keenly disappointed as, just before he started to crawl nearer, he had heard the murmur of their voices in earnest conversation.