Waves and ripples in water, air, and æther

• A
• Actinic rays, 254
• Æther, the, 191
• ——, properties of, 192
• —— wave radiation, range of, 262
• —— waves, various kinds of, 234
• Air, movement of, in a concert-room, 183
• —— necessary for production of sound, 103
• —— particles, mode of motion of, in case of sound wave, 112
• —— waves, 103
• —— ——, interference of, 139
• —— ——, length of, 114
• —— ——, nature of, 114
• —— ——, speed of, 115
• Alphabet used in telegraphy, 274
• America Cup race, pictures of yachts entered for the, 94, 95
• America yacht, the, 93
• Amplitude, 8
• Anti-node, 159
• Apparatus for detecting electric waves, 237
• —— for exhibiting motion of air in case of sound wave, 109
• —— for investigating the laws of falling bodies, 35
• Atlantic waves, height of, 8
• —— ——, length of, 9
• Atomic theory, 226
• B
• Beam of sound focused by collodion lens, 131
• Beats, Helmholtz’s theory of, 165
• ——, musical, 163
• Billows, 1
• Bore, 38
• Branly, Professor, electric wave detector, 211
• Breaking wave, 29
• C
• Canal-boat waves, 100
• Canal wave, 32
• —— —— velocity, 34
• Capillary ripples, 44
• Chromatic scale, 162
• Clef, musical, 160
• Closed organ-pipe, 171
• Cloud waves, 30
• Coherer, Lodge, 212
• ——, Marconi, 276
• Column of air set in vibration by tuning-fork, 158
• Conclusion, 285
• Concords and discords in music, nature of difference between, 162
• ——, musical, 162
• Conditions necessary for production of true wave in a medium, 15
• Conductor, electric, 197
• Conservation of energy, law of, 23
• Conservation of matter, law of, 22
• Convergence of an electric ray by a paraffin lens, 243
• Cornish, Dr. Vaughan, 31
• Corresponding speeds, Froude’s law of, 81
• Cup Races, 93
• Current, electric, 193
• D
• Dark heat, 250
• Deep-sea waves, rule for determining speed of, 11
• —— ——, velocity of, 11
• Definition of a ripple, 42
• —— of wave-frequency, 8
• —— of wave-length, 7
• Depth of water, effect of, on speed of canal wave, 34
• Difference between electric conductors and non-conductors, 198
• —— between velocity of a wave and of a wave-train, 20
• Discords in music, 162
• Dispersion of æther waves, 256
• Distances at which sound can be heard, 120
• E
• Ear, power of, to analyze sound, 182, 183
• Echelon waves made by a duck, 74
• Eddies in liquids, 60
• Eddy, 60
• —— motion, 60
• —— resistance, 68
• Edison phonograph, 142
• Elasticity of the air, 111
• Electric circuit, open, 217
• —— conductor and non-conductor, 197
• —— corpuscles, 227
• —— current, 193
• —— ——, alternating, 194
• —— ——, continuous, 194
• —— —— energy, 215
• —— ——, nature of, 193
• —— displacement, 221
• —— energy, mechanical analogue of, 216
• —— force, 228
• Electric index of refraction, 245
• —— inductance, 214
• —— inertia, 214
• —— oscillations, 185
• —— ——, apparatus for producing, 203
• —— —— in open circuit, 217, 218
• —— —— produced by discharge of Leyden jar, 200
• —— radiation, 238
• —— —— and light, identity in nature of, 251
• —— radiation-detector (Fleming), 224
• —— —— (Miller), 235
• —— radiation, velocity of, 249
• —— ray, reflection of, 241
• —— ——, refraction of, 243
• —— strain, 197
• —— transparency and opacity, 239, 240
• —— wave and air wave compared, 223
• —— —— detector, 210
• —— ——, nature of, 230
• —— ——, production of, 209
• —— waves, 185
• Electrical or Hertz rays, 254
• Electrodeless discharge, 205
• —— ——, apparatus for producing, 206
• Electro-magnet, 195
• Electro-magnetic medium, 220
• —— theory of light, 262
• Electromotive force, 196
• Electronic theory of electricity, 229
• Electrons, 227
• Energy, 21
• ——, kinetic, 25
• —— of electro-static strain, 215
• —— of motion, 25
• —— of moving water, 32
• ——, potential, 25
• ——, two forms of electric, 215
• Ether, the, 191
• Experimental tank, uses of, in ship-design, 86
• —— tanks, 85, 86
• Experiments illustrating surface tension, 40, 41
• Explosion of guns heard at great distances, 120
• F
• Falling bodies, laws of, 35
• Fish, motion of a, 67
• Flame, sensitive, 127
• Flow of liquid in non-uniform tubes, 66
• —— —— in tubes, 65
• —— —— in uniform tubes, 65
• Fog-signals, 123
• ——, influence of wind upon distance at which they are heard, 124
• ——, power absorbed in making, 125
• Free period of vibration, influence upon force required to move a body, 151, 152
• Froude, Mr. William, 81
• Froude’s experimental tank, 81
• —— experiments at Torquay, 81
• G
• Gamut, 160
• —— of æther waves, 260
• Gravitation wave, 40
• Ground swell, 31
• H
• Harmonic curve, 108
• —— motion, 107
• Harmonics, 156
• Hele-Shaw, Professor, 62
• —— ——, discovery of means of producing irrotational motion in liquids, 63
• —— ——, investigations on liquid motion, 63
• Helmholtz’s investigation into nature of musical tones, 167
• —— theory of discords and concords, 165
• Hertz oscillation, 207
• Hertz’s researches. Experiments with electric waves, apparatus for, 234
• Hughes, Professor, investigations on electric waves, made by, 210
• Human ear, the, 181
• Hydraulic gradient, 65
• I
• Illustration of difference between wave-velocity and wave-group velocity, 28
• Inaudible sound, 140
• Index of refraction, 54
• Inductance, 214
• Induction coil for wireless telegraphy, 267
• Inefficiency of present methods of manufacturing light, 265
• Inertia of the air, 111
• Interference of air waves, 139
• —— of electric rays, 248
• —— of ripples and waves, 48
• Irrotational motion, 59
• K
• Kelvin, Lord, investigations on ship waves, 77
• Kinetic energy, 25
• Krakatoa, eruption of, 116
• ——, sound produced by the eruption of, 116
• L
• Laplace, calculation of, concerning sound-velocity, 69
• Law connecting velocity and pressure in liquid motion, 67
• Length of wave, definition of the term, 7
• Light, velocity of, 187, 189
• Liquid flow in constricted tube, 66
• Lodge, Sir Oliver, coherer invented by, 211
• Long wave, 7
• Longitudinal waves, 7
• Luminous efficiency, 264
• —— rays, 254
• M
• Magnetic force, 228
• Major third in music, 161
• Marconi coherer, 276
• —— aerial wire, 266
• ——, experiments with wireless telegraphy across the Atlantic by, 280
• —— system of wireless telegraphy, 276, 279
• Matter, 22
• Maxwell’s electro-magnetic theory of light, 262
• Mechanical explanations of electrical phenomena, 222
• Methods of manufacturing light, 265
• Minor third in music, 161
• Model illustrating longitudinal wave, 114
• —— —— nature of an air wave, 113
• Models, illustrating wave-motion, 5, 6
• Morse alphabet, 274
• Motion, harmonic, 107
• ——, irrotational, 59
• —— of water in sea waves, 3
• ——, periodic, 107
• ——, rotational, 59
• ——, vortex, 59
• Movement of the air in the case of a sound wave, 112
• Music, theory of, 159
• Musical beats, 163
• —— scale, notes of the, 160
• —— tones and noises contrasted, 110
• —— ——, sharp and flat, 161
• N
• Natural period of vibration of a body, 148, 150
• Node, 159
• Non-conductor, electric, 197
• Non-resistance to body moving through perfect fluid, 72
• O
• Octave, 160
• Open electric circuit, 217
• —— organ-pipe, 171
• Optical proof that a sounding body is in vibration, 105, 106
• Organ-pipes, construction of, 169, 171
• ——, distribution of air-pressure in, 172
• ——, overtones of, 173
• ——, relation between length of pipe and length of wave, 173, 174
• Oscillations, electric, 185
• —— of a stretched string, 154
• Oscillator, Hertz, 207
• Oscillatory electric sparks, photographs of, 202
• Overtones, 156
• P
• Pendulum, isochronism of the, 149
• Perfect fluid, 59
• Periodic motion, 107
• —— time, 9
• Phonograph, action of the, 142
• Photographic study of the production of waves, 16
• Photographs of ripples on a mercury surface, 51
• Plane wave, 55
• Potential energy, 25
• Power required to propel ships, 90, 91
• Prism for refracting a beam of sound, 136
• Production of a sound wave, 111
• Q
• Quality of sound, 115
• R
• Radiation, electric, 238
• ——, nature of, 263
• —— of energy from the sun, 284
• Rayleigh, Lord, an acoustic experiment with an open pipe by, 174
• Receiver for wireless telegraphy (Marconi), 275
• Reflection of a beam of sound, 132, 133
• —— of an electric ray, 241
• —— of a wave, 55
• —— of ripples, 46, 47
• Refraction, explanation of, 53, 54
• —— of a beam of sound, 133, 134
• —— of an electric ray, 243
• —— —— by an ice prism, 242
• —— of ripples, 52
• Refractive index, 54
• Relation of wave-velocity and wave-length, 9
• Relay, telegraphic, 236
• Resistance curves of ships, 92
• —— to a body moving through a fluid, causes of the, 68
• Resonance, 148
• ——, an experiment on, 158
• Ripple and wave, distinction between, 40
• —— mark, 30
• ——, reflection of a, 45, 46
• ——, scientific definition of a, 42
• Ripples, 1
• ——, apparatus for producing, 43
• ——, interference of, 48
• ——, intersecting, 49
• —— in the air, 103
• —— on a lake, photographs of, 19
• ——, photography of, 51
• ——, by J. H. Vincent, 54
• —— produced by stone thrown into water, 19
• ——, velocity of, 41, 42, 43
• Rotational motion, 59
• Russell, Scott, Mr., 81
• —— experiments of, on canal-boat waves, 101
• S
• Scale, musical, notes of the, 160
• —— of equal temperament, 162
• Sea waves, 2
• —— ——, motion of, 3
• —— ——, relation of velocity and length in case of, 10
• Semitone, 161
• Sensitive flame, influence of sound upon a, 129
• Severn bore, 38
• Shamrock II., trials of, 97
• Ship bow wave, mode of production, 75, 76
• —— design, 87, 88
• —— ——, the problem of, 73
• —— models, the testing of, 85, 86
• —— resistance, Froude’s law of, 82, 83
• —— waves, 57
• —— ——, complete system of, 78
• —— ——, various systems of, 73
• Short wave, 7
• Sine curve, mode of drawing a, 108
• Singing flame, 175
• Siren, 123
• Skin friction, 59, 68
• —— —— for various classes of ships, 91
• Soap film thrown into vibration by air waves, 145
• —— solution for making bubbles, 144
• Solitary wave, 26
• —— —— and wave-train, difference between, 26
• Sound, and music, 147
• ——, causes in variation in quality of, 142
• —— due to air waves, 103, 104
• —— lens, method of making a, 130
• —— prism, 136
• ——, quality of, 115
• —— signals, 123
• ——, velocity of, in various cases, 126
• Sounding body is in vibration, 104, 105
• Speed of a falling body, 35
• —— of sound, 115
• Stationary waves, 155, 156
• Stone falling into water, photographs of a, 17
• Stream-lines, 64
• —— —— round an ovoid, 71
• Stroh violin, 179
• Structure of the human ear, 181
• Surface tension of liquid, 40
• T
• Temperature, effect of, on sound-velocity, 118
• Tesla coil, 205
• Tidal wave, 38
• —— ——, speed of, 39
• Tides, 39
• Time of vibration of a stretched string, 154
• Tone, 161
• Torpedo, motion of, in water, 67
• Transference of wave-motion, 27
• Transverse ship wave, 79
• —— wave, 7
• True wave, conditions for producing a, 15
• —— ——, definition of a, 12
• Tubes of flow, 64
• —— —— in a liquid, 71
• U
• Utilization of the æther, 284
• V
• Various kinds of resistance to a body moving through a fluid, 68
• Velocity of electric radiation, 249
• —— of light, 189
• —— of sea waves, rule for calculating the, 10
• —— of sound, how affected by temperature, 117
• —— —— in different gases, 126
• —— ——, influence of specific heats upon the, 119
• —— ——, measurements of the, 116
• —— ——, theoretical determination of the, 118
• —— of sound wave, 115
• —— of waves in water, air, and æther compared, 283
• Vernon Boys, Professor, instructions by, for making soap solution, 144
• Vibration rates of musical tones, 160
• —— —— of various æther waves, 252
• Vibrations, forced, 149
• ——, free, 149
• —— giving rise to musical tones, 160
• Vincent, Mr. J. H., 51
• Violin, improved by Mr. Augustus Stroh, 179
• Violin, structure of, 177, 178
• Viscosity of liquids, 58
• Vortex motion, 59
• —— ring in air, 61
• —— ——, production of, in air, 61
• W
• Wave amplitude, definition of, 8
• ——, causes of breaking, 29
• ——, electric, nature of an, 185
• —— frequency, 8
• ——, gravitation, 40
• —— group, velocity of a, 20
• —— length, 7
• —— lengths of various kinds of æther waves, 257
• ——, longitudinal, 7
• —— motion, 2
• —— ——, definition of, 4
• —— —— model, 5
• —— ——, model for illustrating, 13, 14
• —— ——, various kinds of, 4
• —— produced in a canal, 33
• ——, reflection of a, 55, 56
• —— resistance, 68
• Waves, 1
• —— and ripples in the æther, 232
• ——, conditions of, for interference of, 49, 50
• ——, electric, 185
• ——, interference of, 48
• —— in the air, 103
• —— made by canal-boats, experiments on, 101, 102
• —— made by ships, 57, 58
• —— on a snow surface, 31
• —— on clouds, 30
• —— produced by high-speed ships, 79
• ——, refraction of, 52, 53
• ——, sea, 2
• ——, stationary, 155
• —— train, 20
• —— ——, velocity of, 20
• ——, transverse, 7
• —— velocity, a rule for determining, 9
• Wind, influence of, upon distances at which sounds are heard, 120, 121, 122
• Wireless telegraphy across the Atlantic, 280
• —— ——, apparatus for, 267
• —— ——, explanation of, 273
• —— ——, Marconi’s system of, 269
• —— ——, method of conducting, 274
• —— ——, transmitter for, 271
• —— ——, utility of, 281
• Worthington, Professor, photographs of splash of drop, 16, 17
• Y
• Yacht-design, object of, 96
• Yachts entered for the America Cup race, pictures of, 94, 95
• Young, Dr. Thomas, investigations of, on interference of light, 190

THE END.

PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, LONDON AND BECCLES.