Crests, rolling upon the slopes of the boiler. The overflow space O O between E and E^1 is called the Beau de Rochas, 89. Bell, diving, _332_; electric, 119, _120_. Bellows 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 of, _317_. Pianoforte, 277; sounding-board, 280; striking mechanism, 281; strings.