Pythagoreans, notions of the, regarding musical consonance, 410 R Rain, reputed power of obstructing sound, 341-342 —— artificial, passage of sound through, 345 Reeds and reed-pipes, 234 Reeds, the clarinet and flute, 237 Reflection of sound, 45 —— from gases, 332 —— aërial, proved experimentally, 258 Refraction of sound, 51 Resonance, 213 —— of the air, 213-214, 256 —— of coal-gas, 216 —— of the mouth, 242 Resonators, 213 Resultant tones, discovery of, 399 —— conditions of their production, 400 —— experimental illustrations, 401 —— theories of Young and Helmholtz, 404, 406 Reversibility, acoustic, 461-469 Robinson, Dr., his summary of existing knowledge of fog-signals, 307 —— Professor, his production of musical sounds by puffs of air, 89 Rod, vibrations of a, fixed at both ends; its subdivisions and corresponding overtones, 165, 197 —— vibrations of a rod fixed at one end, 166, 197 —— —— of rods free at both ends, 173, 197 S Savart’s experiments on the influence of sounds on jets of water, 457 Schultze’s bristles in the mechanism of hearing, 425 Sea-water, velocity of sound in, 70 Sensitive flames, 274 Smoke-jets, action of musical sounds on, 290 Snow, its reputed power to obstruct sound, 344 Solids, velocity of sound transmitted through, 69, 72 —— musical sounds transmitted through, 115-116, 122 —— determination of velocity in, 211 Sonometer, or monochord, the, 121 Sorge, his discovery of resultant tones, 399