Ben Preddy: Integrating Mathematics with Literacy
Looking upward, I surveyed the ceiling of my prison. It was some thirty or forty feet overhead. . . . The vibration of the pendulum was at right angles to my length. I saw that the crescent was designed to cross the region of the heart. It would fray the serge of my robe-it would return and repeat its operations-again-and again. . . . Notwithstanding its terrifi cally wide sweep (some thirty feet or more), and the hissing vigor of its descent, suffi cient to sunder these very walls of iron, still the fraying of my robe would be all that, for several minutes, it would accomplish.