Sound

by John Tyndall

INDEX

• A
• Acoustic clouds, echoes from, [325]
• —— reversibility, [461]-469
• —— transparency, great change of, [323]
• Air, process of the propagation of sound through the, [33]
• —— propagation of sound through air of varying density, [41]
• —— elasticity and density of air, [54]
• —— influence of temperature on the velocity of sound, [55]
• —— thermal changes produced by the sonorous wave, [60]
• —— ratio of specific heats at constant pressure and at constant volume deduced from velocities of sound, [62]
• —— mechanical equivalent of heat deduced from this ratio, [64]
• —— inference that atmospheric air possesses no sensible power to radiate heat, [66]
• —— velocity of sound in, [69]
• —— musical sounds produced by puffs of air, [89]
• —— other modes of throwing the air into a state of periodic motion, [91]
• —— reflection from heated air, [338]
• Albans, St., echo in the Abbey Church of, [50]
• Amplitude of the vibration of a sound-wave, [42]
• Arago, his report on the velocity of sound, [328]
• Atmosphere, reflection from atmospheric air, [335]
• Atmosphere, its effect on sound, [365]
• Auditory nerve, office of the, [32]
• —— manner in which sonorous motion is communicated to the, [33]
• B
• Bars, heated, musical sounds produced by, [87]
• —— examination of vibrating bars by polarized light, [209]
• Beats, theory of, [385]
• —— action of, on flame, [387]
• —— optical illustration of, [390]
• —— various illustrations of, [397]
• —— dissonance due to beats, [399], [428]
• Bell, experiments on a, placed in vacuo, [36]-37
• Bells, analysis of vibrations of, [190], [198]
• —— fluctuations of, [351]-354
• Bourse, at Paris, echoes of the gallery of the, [49]
• Burners, fish-tail and bat’s-wing, experiments with, [277]
• C
• Carbonic acid, velocity of sound in, [65]
• —— reflection from, [335]
• —— oxide, velocity of sound in, [69]
• Chladni, his tonometer, [168]
• —— his experiments on the modes of vibration possible to rods free at both ends, [174]
• —— his analysis of the vibrations of a tuning-fork, [176]
• Chladni, his device for rendering the vibrations visible, [178]
• —— illustrations of his experiments, [180]
• Chords, musical, [432]
• Clang, definition of, [153]
• Claque-bois, formation of the, [175], [197]
• Clarinet, tones of the, [237]
• Clouds, sounds reflected from the, [49]
• Corti’s fibres, in the mechanism of the ear, [426]
• Cottrell, Mr., his experiment of an echo from flame, [339]
• D
• Derham, Dr., on fog-signals, [306]
• Diatonic scale, [263]
• Difference-tones, [404]
• Diffraction of sound, 76 note, [78]
• Disks, analysis of vibrations of, [187], [198]
• Dissonance, cause of, [428]
• —— graphic representation of, [430]
• Doppler, his theory of the colored stars, [113]
• E
• Ear, limits of the range of hearing of the, [106], [118]
• —— causes of artificial deafness, [108], [119]
• —— mechanism of the ear, [424]
• —— consonant intervals in relation to, [426]
• Echoes, [48]
• —— instances of, [48]-50
• —— aërial, production of, [328]-329
• —— from flame, [339]-340
• —— reputed cloud echoes, [328]
• Eolian harp, formation of the, [159]-160
• Erith, effects of the explosion of 1864 on the village and church of, [53]
• Eustachian tube, the, [198]
• —— mode of equalizing the air on each side of the tympanic membrane, [109], [119]
• F
• Falsetto voice, causes of the, [239]
• Faraday, Mr., his experiment on sonorous ripples, [195]
• Fiddle, formation of the, [123]
• —— sound-board of the, [123]
• —— the iron fiddle, [169], [197]
• —— the straw-fiddle, [175], [197]
• Flames, sounding, [261], [302]
• —— rhythmic character of friction, [260], [301]
• —— influence of the tube surrounding the flame, [263], [302]
• —— singing-flames, [264], [302]
• —— effect of unisonant notes on singing-flames, [275]
• —— action of sound on naked flames, [275], [302]-304
• —— influence of pitch, [283]
• —— extraordinary delicacy of flames as acoustic reagents, [285]
• —— the vowel-flame, [286]
• —— discovery of a new sensitive flame by Philip Barry, [288]
• —— echo from, [339]
• —— action of beats on flame, [387]
• Flute, tones of the, [237]
• Fog, its want of power to obstruct sound, [348]
• —— observations in London, [348]
• —— fog-signals in, [355]
• —— artificial, experiments on, [357]
• Fog-signals, researches on the acoustic transparency of the atmosphere in relation to the question of, [305]
• —— station at South Foreland, [309]
• —— instruments and observations, [309]
• —— variations of range, [315]-316
• —— contradictory results, [317]
• —— solution of contradictions, [317]-323
• —— extraordinary case of acoustic opacity, [318]
• —— in fogs, [355]
• —— minimum range of, [371]
• —— its position, [370]
• —— disadvantages of the gun, [368]
• Foreland, South, fog-signal station at, [309]
• —— fog at, [354]
• G
• Gaines’s Farm, account of the battle of, [324]
• Gases, velocity of sound in, [69]
• Gun, range of, for fog-signals, [312]-313
• —— inferiority to the siren, [369]
• —— its disadvantages as a signal, [368]
• H
• Hail, doubt as to its power to obstruct sound, [342]
• Harmonic tones of strings, [152]-154
• Harmony, [410]
• —— notions of the Pythagoreans, [411]
• —— Euler’s theory, [419]
• —— conditions of harmony, [411]
• —— influence of overtones on harmony, [429]
• —— graphic representations of consonance and dissonance, [431]
• Harmonica, the glass, [176]
• Hawksbee, his experiment on sounding bodies placed in vacuo, [36]
• Hearing, mechanism of, [424]
• Heat, thermal changes in the air produced by the sonorous wave, [60]
• —— ratio of specific heats at constant pressure and at constant volume deduced from velocities of sound, [64]
• —— mechanical equivalent of heatdeduced from this ratio, [66]
• —— inference that atmospheric air possesses no sensible power to radiate heat, [68]
• —— musical sounds produced by heated bars, [87]
• Helmholtz, his theory of resultant tones, [405], [406]
• —— —— consonance, [414], [420]
• Herschel, Sir John, his article on “Sound” quoted, [50]
• —— his account of Arago’s observation on velocity of sound, [328]
• Hooke, Dr. Robert, his anticipation of the stethoscope, [75]
• —— his production of musical sounds by the teeth of a rotating wheel, [85]
• Horn, as an instrument for fog-signalling, [310]-311
• Hydrogen, action of, upon the voice, [40]
• —— deadening of sound by, [38]
• —— velocity of sound in, [55], [69]
• I
• Inflection of sound, [53]
• —— case of the Erith explosion, [53]
• Interference of sonorous waves, [381]-382, [407]
• —— extinction of sound by sound, [383], [408]
• —— theory of beats, [385], [408]
• Intervals, optical illustration of, [440]
• J
• Joule’s equivalent, [67]
• Jungfrau, echoes of the, [49]
• K
• Kaleidophone, Wheatstone’s, formation of, [170], [196]
• Kundt, M., his experiments, [344]
• L
• Laplace, his correction of Newton’s formula for the velocity of sound, [58]-59
• Le Conte, Professor, his observation upon sensitive naked flames, [274]-275
• —— on the influence of musical sounds on the flame of a jet of coal-gas, [454]-460
• Lenses, refraction of sound by, [51]
• Light, analogy between sound and, [45]-50
• —— analogy of, [320]
• Liquids, velocity of sound in, [69]
• —— transmission of musical sounds through, [113]
• —— constitution of liquid veins, [291]
• —— action of sound on liquid veins, [294], [303]-304
• —— Plateau’s theory of the resolution of a liquid vein into drops, [295]
• —— delicacy of liquid veins, [300]
• Lissajous, M., his method of giving optical expression to the vibrations of a tuning-fork, [93]
• —— illustration of beats of two tuning-forks, [390]
• M
• Mayer, his formula of the equivalent of heat, [66]
• Melde, M., his experiments with vibrating strings, [141], [427]
• —— and with sonorous ripples, [194]
• Metals, velocity of sound transmitted through, [72]
• —— determination of velocity in, [73]
• Molecular structure, influence of, on the velocity of sound, [73], [212]
• Monochord or sonometer, the, [121]
• Motion, conveyed to the brain by the nerves, [31]
• —— sonorous motion. See Sound.
• Mouth, resonance of the, [241]-242
• Music, physical difference between noise and, [82], [117]
• —— a musical tone produced by periodic, noise by unperiodic, impulses, [83], [117]
• —— production of musical sounds by taps, [84], [117]
• —— —— by puffs of air, [89], [117]
• —— pitch and intensity of musical sounds, [90], [92], [117]
• —— description of the siren, [97]
• —— definition of an octave, [105]
• —— description of the double siren, [110]
• —— transmission of musical sounds through liquids and solids, [113]
• —— musical chords, [432]-433
• —— the diatonic scale, [432]-433
• —— See also Harmony.
• Musical-box, formation of the, [169], [197]
• N
• Nerves of the human body, motion conveyed by the, to the brain, [31]
• —— rapidity of impressions conveyed by, 31 note
• Newton, Sir Isaac, his calculation of the velocity of sound, [58]
• Nodes, [131]-132
• —— the nodes not points of absolute rest, [135]
• —— nodes of a tuning-fork, [175], [177]
• —— rendered visible, [177], [180]
• —— a node the origin of vibration, [251]
• Noise, physical difference between music and, [82], [117]
• O
• Octave, definition of an, [105]
• Organ-pipes, [219], [256]
• Organ-pipes, vibrations of stopped pipes, [221], [256]
• —— —— Pandean pipes, [224]
• —— —— open pipes, [224], [256], [260]
• —— state of the air in sounding-pipes, [227], [257]
• —— reeds and reed-pipes, [234]
• Otolites of the ear, [425]
• Overtones, definition of, [153]
• —— relation of the point plucked to the, [155]
• —— corresponding to the vibrations of a rod fixed at both ends, [165]
• —— of a tuning-fork, [177]
• —— rendered visible, [177], [179]
• —— of rods vibrating longitudinally, [207]
• —— of the siren, [415]
• —— influence of overtones on harmony, [429]
• P
• Pandean pipes, the, [224]
• Piano-wires, clang of, [158]
• —— curves described by vibrating, [160]
• Pipes. See Organ-pipes
• Pitch of musical sounds, [90]
• —— illustration of the dependence of pitch on rapidity of vibration, [100]
• —— relation of velocity to pitch, [211]-212
• —— velocity deduced from pitch, [233]
• Plateau, his theory of the resolution of a liquid vein into drops, [295]
• 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]
• Sound, production and propagation of, [32], [77]
• —— experiments on sounding bodies placed in vacuo, [36], [77]
• —— deadened by hydrogen, [38]
• —— action of hydrogen upon the voice, [40]
• —— propagation of sound through air of varying density, [40]
• —— amplitude of the vibration of a sound-wave, [42], [77]
• —— the action of sound compared with that of light and radiant heat, [45]
• —— reflection of, [45], [77]
• —— echoes, [48]-50, [78]
• —— sounds reflected from the clouds, [49]-50
• —— refraction of sound, [51], [77]
• —— diffraction of sound, [53], [78]
• —— influence of density and elasticity on velocity, [54], [78]
• —— influence of temperature on velocity of sound, [55], [78]
• —— determination of velocity, [57], [78]
• —— Newton’s calculation, [58], [80]
• —— Laplace’s correction of Newton’s formula, [59], [80]
• —— thermal changes produced by the sonorous wave, [60], [80]
• —— velocity of sound in different gases, [69], [81]
• —— —— in liquids and solids, [70]-73, [81]
• —— influence of molecular structure on the velocity of sound, [73], [81]
• —— velocity of sound transmitted through wood, [74], [81]
• —— diffraction of, 76 note, [78]
• —— physical distinction between noise and music, [82]
• —— musical sounds periodic, noise unperiodic, impulses, [83]
• —— —— produced by taps, [84]
• —— —— by puffs of air, [89]
• —— pitch and intensity o£ musical sounds, [90]
• —— vibrations of a tuning-fork, [91]
• —— M. Lissajous’s method of giving optical expression to the vibrations of a tuning-fork, [93]
• —— definition of the wave-length, [96]
• —— description of the siren, [97]
• —— determination of the rapidity of vibration, [101]
• —— and of the length of the corresponding sonorous wave, [102]
• —— various definitions of vibration and of sound-wave, [103]
• —— limits of range of hearing of the ear: highest and deepest tones, [106]
• —— double siren, [110]
• —— transmission of musical sounds through liquids and solids, [113]-117
• —— vibrations of strings, [120]
• —— the sonometer, or monochord, [121]
• —— influence of sound-boards, [123]
• —— laws of vibrating strings, [125]
• —— direct and reflected pulses, [129]
• —— stationary and progressive waves, [130]
• —— nodes and ventral segments, [130], [133]
• —— application of the results to the vibration of musical strings, [138]
• —— M. Melde’s experiments, [141], [427]
• —— longitudinal and transverse impulses, [144]
• —— laws of vibration thus demonstrated, [148], [162]
• —— harmonic tones of strings, [152], [163]-164
• —— definitions of timbre, or quality, of overtones and clang, [153], [164]
• —— relation of the point of string plucked to overtones, [155]-156
• —— vibrations of a rod fixed at both ends; its subdivisions and corresponding overtones, [165]
• —— —— of a rod fixed at one end, [166]
• —— Chladni’s tonometer, [168]
• —— Wheatstone’s kaleidophone, [170], [196]
• —— vibrations of rods free at both ends, [173], [197]
• —— nodes and overtones of a tuning-fork, [175]-178, [197]
• —— —— rendered visible, [177]-179, [197]-198
• —— vibrations of square plates, [184], [198]
• —— —— of disks and bells, [187]-190, [198]-199
• —— sonorous ripples in water, [193]
• —— Faraday’s and Melde’s experiments on sonorous ripples, [194]-195
• —— longitudinal vibrations of a wire, [200]
• —— relative velocities of sound in brass and iron, [203], [206]
• —— examination of vibrating bars by polarized light, [209]
• —— determination of velocity in solids, [211]
• —— relation of velocity to pitch, [212]
• —— resonance, [213], [253], [256]
• —— —— of the air, [213], [256]
• —— —— of coal-gas, [216], [256]
• —— description of vowel-sounds, [240]
• —— Kundt’s experiments on sound-figures within tubes, [244]-251, [259]
• —— new methods of determining velocity of sound, [247]-251, [259]
• —— causes that obstruct the propagation of, [306]
• —— action of fog upon sound, [307]
• —— contradictory results of fog-signalling, [317]
• —— solution of contradictions of fog-signalling, [317]-318
• —— extraordinary case of acoustic opacity, [318]
• —— great change of acoustic transparency, [323]
• —— noise of battle unheard, [324]
• —— echoes from invisible acoustic clouds, [325], [375]
• —— report of Arago on the velocity of, [328]
• —— aërial echoes of, [330]
• —— demonstration of reflection from gases, [332]
• —— reflection from vapors, [336]
• —— —— heated air, [337]
• —— echo from flame, [340]
• —— investigations of the transmission of sound through the atmosphere, [341]
• —— action of hail and rain, [341]
• —— action of snow, [344]
• —— passage through tissues, [345]
• —— —— artificial showers, [346]
• —— action of fog, [347]
• —— fluctuations of bells, [351]-354
• —— action of wind, [361]
• —— atmospheric selection, [365]
• —— law of vibratory motions in water and air, [377], [407]
• —— superposition of vibrations, [381]
• —— interference and coincidence of sonorous waves, [382]-383, [407]
• —— extinction of sound by sound, [384], [407]
• —— theory of beats, [385], [408]
• —— action of beats on flame, [387]
• —— optical illustration of beats, [390], [408]
• —— various illustrations of beats, [397]
• —— resultant tones, [399], [409]
• —— —— conditions of their production, [400]
• —— —— experimental illustrations, [401]
• —— —— theories of Young and Helmholtz, [405]-406
• —— difference-tones and summation-tones, [405]
• —— combination of musical sounds, [410]
• —— sympathetic vibrations, [421]
• —— mode in which sonorous motion is communicated to the auditory nerve, [426]
• Sound-boards, influence of, [123]-124
• Sound-figures within tubes, M. Kundt’s experiments with, [244]-251
• Stars, Doppler’s theory of the colored, [113]
• Steam-siren, description of, [309]
• —— conclusive opinion as to its power for a fog-signal, [370]
• Stethoscope, Dr. Hook’s anticipations of the, [74]
• Stokes, Professor, his explanation of the action of sound-boards, [124]
• —— his explanation of the effect of wind on sound, [363]
• Straw-fiddle, formation of the, [175], [197]
• Strings, vibration of, [120]
• —— laws of vibrating strings, [125]
• —— combination of direct and reflected pulses, [129]
• —— stationary and progressive waves, [130]
• —— nodes and ventral segments, [130]-133
• —— experiments of M. Melde, [141], [427]
• —— longitudinal and transverse impulses, [144]
• —— laws of vibration thus demonstrated, [148], [162]
• —— harmonic tones of strings, [152], [163]-164
• —— timbre, or quality, and overtones and clang, [153], [164]
• —— Dr. Young’s experiments on the curves described by vibrating piano-wires, [160]
• —— longitudinal vibrations of a wire, [200]
• —— —— with one end fixed, [204]
• —— —— with both ends free, [206]
• Summation-tones, [405]
• Siren, description of the, [97]
• —— sounds, description of the, [97]
• —— its determination of the rate of vibration, [101]
• —— the double siren, [110], [411]-412
• —— the echoes of the, [330]
• T
• Tartini’s tones, 399. See Resultant Tones.
• Timbre, or quality of sound, definition of, [153]
• Tisley, Mr., his apparatus for the compounding of rectangular vibrations, [447]
• Toepler, M., his experiment on the rate of vibration of the flame, [268]
• Tonometer, Chladni’s, [168]
• Trumpets, range of, for fog-signals, [313]
• Tuning-fork, vibrations of a, [93]
• —— M. Lissajous’s method of giving optical expression to the vibrations, [93]
• —— strings set in motion by tuning-forks, [142]
• —— vibrations of the tuning-forks as analyzed by Chladni, [176]
• —— nodes and overtones of a, [171], [197]
• —— interference of waves of the, [395]
• V
• Vapors, reflection from, [336]
• Velocity of sound, influence of density and elasticity on, [54]
• —— influence of temperature on, [55]
• —— determination of, [57]
• —— Newton’s calculation, [58]
• —— velocity of sound in different gases, [69]
• —— and transmitted through various liquids and solids, [70]-73
• —— relative velocities of sound in brass and iron, [203], [206]
• —— relation of velocity to pitch, [212]
• —— velocity deduced from pitch, [233]
• Ventral segments, [132]
• Vertical jets, action of sound on, [297], [304]
• Vibrations of a tuning-fork, [93]
• —— method of giving optical expression to the vibrations of a tuning-fork, [93]
• —— illustration of the dependence of pitch on rapidity of vibration, [101]
• —— the rate of vibration determined by the siren, [101]
• —— determination of the length of the sound-wave, [102], [118]
• —— various definitions of vibrations, [103], [118]
• —— vibrations of strings, [120]
• —— laws of vibrating strings, [125]
• —— direct and reflected pulses illustrated, [129]
• —— application of the result to the vibration of musical strings, [138]
• —— M. Melde’s experiments on the vibration of strings, [141], [427]
• —— longitudinal and transverse impulses, [144]
• —— Vibrations of a red-hot wire, [147]
• —— laws of vibration thus demonstrated, [148], [162]
• —— new mode of determining the law of vibration, [148], [150]
• —— harmonic tones of strings, [152], [163]
• —— vibrations of a rod fixed at both ends; its subdivisions and corresponding overtones, [165]
• —— vibrations of a rod fixed at one end, [166]
• —— Chladni’s tonometer, [168]
• —— Wheatstone’s kaleidophone, [170]
• —— vibrations of rods free at both ends, [173]
• —— nodes and overtones rendered visible, [177]-179
• —— vibrations of square plates, [184]
• —— —— of disks and bells, [187]-190
• —— longitudinal vibrations of a wire, [200], [255]
• —— —— with one end fixed, [204]
• —— —— with both ends free, [206]
• —— divisions and overtones of rods, vibrating longitudinally, [207]
• —— examination of vibrating bars by polarized light, [209]
• —— vibrations of stopped pipes, [221]
• —— —— of open pipes, [224]
• —— a node the origin of vibration, [251]
• —— law of vibratory motions in water and air, [377]
• —— superposition of vibrations, [381]
• —— theory of beats, [385]
• —— sympathetic vibrations, [421]
• —— M. Lissajous’s method of studying musical vibrations, [433]
• —— apparatus for the compounding of rectangular vibrations, [447]
• Violin, formation of the, [123]
• —— sound-board of the, [123]
• —— the iron fiddle, [169], [197]
• Voice, human, action of hydrogen upon the, [40]
• —— sonorous waves of the, [104]
• —— description of the organ of voice, [238]
• —— causes of the roughness of the voice in colds, [239]
• —— causes of the squeaking falsetto voice, [239]
• —— Müller’s imitation of the action of the vocal chords, [240]
• —— formation of the vowel-sounds, [240]-241
• —— synthesis of vowel-sounds, [242]-243
• Vowel-flame, the, [286]
• Vowel-sounds, formation of the, [240]
• —— synthesis of, [242]-243
• W
• Water-Waves, stationary, phenomena of, [136]
• Water, velocity of sound in, [70]
• —— transmission of musical sounds through, [113]
• —— effects of musical sounds on jets of water, [291]-292
• —— delicacy of liquid veins, [294]
• —— theory of the resolution of a liquid vein into drops, [295], [304]
• —— law of vibratory motions in water, [377]
• Wave-length, definition of, [96]
• —— determination of the length of the sonorous wave, [102]
• Wave-length, definition of sonorous wave, [104]
• Wave-motion, illustration, [128]-133
• —— stationary waves, [133]
• —— law of, [377]
• Waves of the sea, causes of the roar of the breaking, 88 note
• Weber, Messrs., their researches on wave-motion, [133]
• Wetterhorn, echoes of the, [49]
• Wheatstone, Sir Charles, his kaleidophone, [170]
• —— his apparatus for the compounding of rectangular vibrations, [448]
• Whistles, range of, for fog-signals, [313]
• Wind, effect on sound, [361]
• Wires. See Strings
• Wood, velocity of sound transmitted through, [74]
• —— musical sounds transmitted through, [115]
• —— the claque-bois, [175]
• —— determination of velocity in wood, [211]
• Woodstock Park, echoes in, [56]
• Y
• Young, Dr. Thomas, his proof of the relation of the point of a string plucked to the overtones, [155]
• —— on the curves described by vibrating piano-wires, [160]-161
• —— his theory of resultant tones, 404