Henry Petroski discusses how the chimney sweep he hired successfully installed a new chimney in place of the existing chimney that had begun to deteriorate. The chimney sweep and his helper brought a piece of polished granite in the bed and three ladders. The sweep pulled himself into a kneeling position atop the flat chimney cap and proceeded to hack through and remove the few bolts that had been installed to fix the cap onto the open brickwork. He, then, pulled out the chimney. He placed it across the rails of the ladder and slid it down the slope of the roof as he himself backed down rung by rung ahead of it. When he reached the juncture of the roof ladder with the one against the gable, the sweep came over and held the old chimney cap on the ladder rails while the helper mounted the second ladder.