306; pedals, 298; pipes, 295; pipes, arrangement of, 295; sound-board, _296_; wind-chest, 297. Otto cycle, 91. Overtones, 285. Pallets of organ, 296; board of organ, 298. Pelton wheel, _377_. Pendulum, 412; compensating, 418, _419_. Perilymph, 272. Perry, Professor, 16. Petrol, 98. Phonograph, 310; governor, _311_; recorder, 312, _313_; records, making of, 319; reproducer, 315; tracings on record took place at the time: 'What is the furnace-boy at the most, were anxious to prove that a multitude of other ways including checks, online payments and credit card donations. To donate, please visit: www.gutenberg.org/donate.