INDEX.

Acceleration of moment of momentum, 377

Aldebaran, 27, 28

Anderson, Dr., 356

Andromeda, Great Nebula in, 43, 204

Antinous, Cluster of stars in, 353

Apteryx, Rudimentary wing-bones of, 364, 366

——, Skeleton of, 364, 366

——, The, 363, 365

Arcturus, Spectrum of, 85

Argon, 265

Argus and surrounding stars, 103

Ariel, 338

Boring, The great, 123

Brooks’ comet, 89

Bunsen burner, The, 283

Butterfly and the oak-tree, The, 15

Calcium, 274

Capella, Spectrum of, 61–64

Carbon, 280

Ceres, 311

Change of moment of momentum, 375

Cluster, Nebulous region round a, 33

Clusters of stars, 53–60, 203

—— —— of 17th magnitude, 353

Coal-unit, 110

Collisions, 219, 380

——, Cause of formation of nebulæ, 356

Comets, 37

Comet, Brooks’, 89

—— of 1882, 119

——, Spectrum of, 290

Common, Dr. A. A., 44

Concord, The first, 294–307

——, The second, 308–323

——, The third, 324–336

Conglomerates, 159

Conservation of moment of momentum, 374

Corona of the sun, 117

Crab nebula, The, 19, 44

Crossley Reflector, The, 45, 46, 48, 49, 50, 67, 199

Cygnus, Nebula in, 329

Dark bodies in universe, 355

Darwin, Professor G. H., 153, 254, 332

Darwinian theory, 10, 268, 362

Dewar, Professor, 144, 272

Diurnal motion, The, 21

Dumb-bell nebula, 43, 44, 45, 46, 50, 74, 195

Dust from Krakatoa, 185

Earth, Heat in interior of, 134, 367

——, ——, Cause of, 153

——, History of, 122–157, 251

——, Rigidity of, 162

Earth-moon system, 253, 332

Earthquakes, 158–190

—— in England, 175

——, Routes of, 171

Emission of sun heat, 373

Energy between two attracting masses, 370

—— given out in contraction of nebula, 370

—— of a system, 216, 235

Equivalent of heat, 88

Eros, 312

Evaluation of sun heat given out in contraction, 371

Everett, Professor, 149

Fire-mist, The, 268

“Flash” spectrum, 70

383Foot-pound, 91

Foraminifera, 367

Friction and tides, 381

Gas in rarefaction, 118

H and K lines, 70, 276

Heat, Cause of, 153

——, Equivalent of, 88

—— given out in contraction of nebula, 369

—— in interior of the earth, 134, 367

——, Unit of, 80, 89

Helium, 277

Helmholtz, 86, 96, 100

Hercules, Star-cluster in, 52, 53, 56, 57, 59

Herschel, Sir William, 4, 11, 72, 73, 74

Huggins, Sir W., 60, 61, 63, 65

Huxley, Professor, and Darwinian theory, 362

Huyssen, Captain, 127

Hydrogen in spectrum of Nova Persei, 358

“Inflammation” and nebular theory, 361

Joule’s equivalent of heat, 88

Jupiter, 23, 25, 26, 29, 208, 237, 310, 327

K and H lines, 70, 276

Kant, Immanuel, 4, 5, 72, 73, 74, 327

Keeler, Professor, 45–48, 67, 73, 199, 200, 202, 245

Kelvin, Lord, 153, 162

Krakatoa, 176–189

Langley, Professor, 78

Laplace, 4, 72, 73, 74, 206

Lassell, Mr., 338, 340

Lick Observatory, 41, 43, 44, 45

Lockyer, Sir Norman, 277

Lyra, Ring nebula in, 249

Mars, 25, 26, 27, 28, 29, 311, 341, 349

——, Satellites of, 341

Mécanique Céleste, 5, 8

Mercury, 23, 25, 26, 29, 208

Meteors, 37

Milky Way, 205, 206, 214, 220

Milne, Professor, 165

Moment of momentum, 222, 226, 240, 352

—— ——, Acceleration of, 377

—— ——, Change of, 375

—— ——, Conservation of, 374

Momentum, Moment of, 222, 220, 240, 352

Monoceros, Nebulous region round a cluster in, 33

Moon, Origin of, 254

——, Surface of, 255

Nautilus, The, 367

Nebula, Contraction of, Heat given out in, 369

——, ——, Energy given out in, 370

—— in Orion, The great, 40, 41, 42, 44, 46, 50, 74, 195, 242

—— ——, ——, Spectrum of, 63, 64, 65

——, The great spiral, 192, 193

Nebulæ, 40, 41, 43, 45, 47, 50, 57, 58, 66, 67, 71, 73, 105, 120, 157, 191–206, 242, 247, 249, 256, 257, 258, 259, 296, 329, 345, 348–360

——, Development of, 242

——, Discovery of, 11

——, Number of, 67, 200

Nebular anecdote, 362

—— Theory, The, 2, 3, 72, 74, 157, 205, 266, 292, 307, 323, 328, 331, 337–347, 362, 368

Nebulosity, Faint diffused, in Perseus, 17

Neptune, 37

——, Satellites of, 330, 340

Newcomb, Professor, 238

Norway, Conglomerates in, 159

Nova Persei, 358

—— ——, Spectrum of, 358, 359, 360

Oak-tree and the butterfly, The, 15

Oberon, 338

Orbits of the planets, 208

Orion, 22

384Orion, Great nebula in, 40, 41, 42, 44, 46, 50, 74, 195, 242

——, Spectrum of, 63, 64, 65

Pegasus, Nebula in, 47, 345

Perseus, A faint diffused nebulosity in, 17

——, New star in, 356

Photosphere, The, 69

Pickering, Professor, 358

“Plane, Principal,” The, 225, 352, 379

Planetary system, The, 37, 208

Planets, 22, 26, 28

——, Movement of, 35, 311

——, Orbits of, 208, 298

——, Rotation of, on their axes, 325

Platinum, 263

Pleiades, 22

——, Nebulae in, 71

Potassium, 272

“Plane, Principal” The, 225, 352, 379

Probabilities, Theory of, 305

Radiation of sun’s heat, 82

Ramsay, Professor, 278

Ray nebulæ, 201, 211

Rigidity of the earth, 162

Ring nebula in Lyra, The, 249

Roberts, Dr. Isaac, 198

Rosse, Lord, 57, 196–201

Rowland, Prof. Henry, 273

Sagittarius, Nebula in, 105

Satellites, 37, 209

Saturn, 25, 26, 29, 220, 233

——, Dweller in, and the Sirian, 14

——, Ring of, 210, 220, 231, 232, 233, 234

Scheiner, Professor, 202, 204

Seismometer, The, 165

Sirian, The, and the dweller in Saturn, 14

Sirius, 215, 216

Smiths, The parable of the, 303

Solar system, 36, 207

——, Energy of, 350

——, Evolution of, 20, 246–260, 349

——, Origin of, 351

Solar system, Scale of, 29, 30, 31

Spectra, Continuous, 68, 203

——, Discontinuous, 68

Spectroscope, The, 60, 271

Spiral form in Nature, 256, 257

Spiral nebula, The great, 192, 193, 247

Spiral nebulæ, 191–206, 211, 212, 213, 220, 243, 247, 256, 257, 258, 259, 296, 345

Star-clusters, 53–60

Star, Spectrum of, 64

Stars distinguished from planets, 28, 29

Stoney, Dr. G. Johnstone, 279

Sun compared with the planets, 26, 29

——, Corona of, 117

——, Contraction of, 99, 373

——, Density of, 102, 115

——, Heat of, 75–94, 95–111, 371, 372, 373

——, History of, 112–121, 251

——, Nebulous part of, 121

——, Spectrum of, 61, 62, 69, 70, 85, 273

——, Surface of, 278

——, Velocity of, 354

——, Weight of, 101

Sun heat, given out in contraction, Evaluation of, 371, 372

——, Present emission of, 373

Sunsets, The Krakatoa, 189

Système du Monde, 8

Thermometer for testing the heat of the earth’s interior, 129

Thomson, Prof. J. J., 316

Tides and friction, 381

Titania, 338

Umbriel, 338

Unit of heat, 80, 89

Uranus, 37, 238, 239

——, Satellites of, 238, 338

Venus, 23, 25, 26, 29, 208, 325

Volcanoes, 158–190

Voltaire, Fable of, 14

Waves caused by Krakatoa earth quake, 179, 182, 183

Printed by Cassell & Company, Limited, La Belle Sauvage, London, E.C.

20.509

Transcriber’s Notes: The raised dot (·), used to indicate multiplication, was confused with the decimal point in several numbers. The raised dot has been changed to the decimal point in numbers and the raised dot used only for multiplication. In places where “×” was used for multiplication, it was left as the author wrote it. Missing or obscured punctuation was silently corrected. Typographical errors were silently corrected. Inconsistent spelling and hyphenation were made consistent only when a predominant form was found in this book.