And the foreman and David went through the place that would be the front hall when it was done, with the front stairs going up out of it; and some carpenters were working there now and there was a great mess. "What are the carpenters doing?" David asked. "They're nailing on laths, Davie," the foreman answered. "Laths, you see, are the little thin sticks that go on the up-and-down sticks of the walls, and the plaster goes on them and squeezes between them. Then, when it hardens, the part that is between the laths holds the rest of the plaster up and against the wall." David nodded, but they were in the back hall now, with the back stairs going up out of it, and he forgot the carpenters and the laths. Under the back stairs were some stairs that went down to the cellar, and the foreman started down. "Be careful of the steps, Davie," said the foreman. "They have to have these rough boards on them now, while the workmen are here, so that the real steps won't get all dirty and worn. When the men are almost through, about the last thing they do is to lay floors and put nice boards on the stairs." David couldn't see very well, but he could feel that the boards of the stairs were uneven and rough, and some of them were small; but he was careful, and he went slowly, and at last he was on the cellar floor. Far off in the very end of the cellar he saw a lantern lighted, and a flickering light which moved about, high up. Then, as he got used to the darkness, he saw the legs of two men; and they had great wrenches and were doing something to long pipes, and they had a candle which they held close up to the pipes, so that they could see. And the pipes went along close to the beams overhead, so that the men were all the time bumping their heads and knocking their elbows on the beams, and they didn't have room enough to work. That was the reason why David had seen only their legs when he first came down. It wasn't a very convenient way to work, but the men didn't seem to mind. Perhaps they were used to it. "Are those the pipes that the water goes through?" David asked. "Yes, Davie," the foreman said. "It comes in through the wall there, close down to the floor, from that pipe that you saw the men laying in the street. "Then it goes up and through these pipes to the back of the cellar, and then up again to the kitchen and the pantry and the bathrooms. "It isn't much fun being down here, is it?" "No," David said, "it isn't." The foreman laughed. "Well, you wait a half a jiffy and we'll go up." So David waited while the foreman took a paper out of his pocket. And first he looked at the paper and then he looked at the pipes, and then he looked at the paper again. Then he folded the paper and put it into his pocket, and he took David's hand and they went up the cellar stairs, and through a door into the kitchen. There David saw the legs of two other men who were lying down under the sink.