Waves and ripples in water, air, and æther

INDEX.

Reading edition

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

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

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

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

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

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

Gamut, 160

—— of æther waves, 260

Gravitation wave, 40

Ground swell, 31

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

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

Kelvin, Lord, investigations on ship waves, 77

Kinetic energy, 25

Krakatoa, eruption of, 116

——, sound produced by the eruption of, 116

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

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

Natural period of vibration of a body, 148, 150

Node, 159

Non-conductor, electric, 197

Non-resistance to body moving through perfect fluid, 72

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

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

Quality of sound, 115

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

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

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

Utilization of the æther, 284

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

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

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.

Transcriber’s Note (continued)

Errors in punctuation and simple typos have been corrected without note. Variations in spelling, hyphenation, accents, etc., have been left as they appear in the original publication unless as stated in the following:

Page 56 – “sea-side” changed to “seaside” (At the seaside)

Page 56 – “sea-side” changed to “seaside” (study of seaside pools)

Page 136 – “sound ray” changed to “sound-ray” in Fig. 51 caption

Page 145 – “limelight” changed to “lime-light” (lime-light lantern)

Page 156 – “over-tones” changed to “overtones” (accompanied by the harmonics or overtones)

Page 162 – “key-board” changed to “keyboard” (keyboard of a piano)

Page 176 – “aërial” changed to “aerial” (stationary aerial oscillation)

Page 177 – “horse-hair” changed to “horsehair” (bow made of horsehair)

Page 274 - “Full Stop — — — — — —” changed to “Full Stop — ——— — ——— — ———”

Footnotes have been re-indexed using numbers and placed before the Index.