Part 2 — INDEX

Abbe, Cleveland, corona of 1878 176 177

Aberdour, Lord, solar chromosphere, 68

Aberration, discovered by Bradley, 3, 15; cause of, 31, 231 investigations of, 241 438

Abney, daylight coronal photographs, 179; infra-red photography, 210 223 438

Absorption, terrestrial atmospheric, 134 211 214-216 225; solar, 134-136 172 213 221 222 225 277 correlative with emission, 135 136 140

Adams, discovery of Neptune, 79-82; lunar acceleration, 271 orbit of November meteors, 331

Aerolites, falls of, 339 340

Airy, solar translation, 39; observations during eclipses, 62, 64, 70 Astronomer-Royal, 79 search for Neptune, 80, 81 corona of 1851 175 solar parallax, 227 236 transit of Venus, 233 Mercurian halo, 235 lunar atmosphere, 264

Aitken, double star discoveries, 419

Albedo, of Mercury, 246; of Venus, 255 of Mars, 283 of minor planets, 288 of Jupiter, 290 of Saturn, 303 of Uranus, 304

Alexander, spiral nebulæ, 118; observation during eclipse, 245

Algol, variability of light, 10, 390; eclipses, 390 nature of system, 391

Altitude and azimuth instrument, 120 note, 121

Amici, comet of 1843 103

Anderson, discovery of Nova Aurigæ, 396; of Nova Persei, 400

Andrews, conditions of liquefaction, 151

Ångström, C. J., Optical Researches, 138; spark spectrum, 139 nature of photosphere, 152 solar spectroscopy, 210 212 hydrogen in sun, 211 temperature of stars, 375

Ångström, K., infra-red solar spectrum, 210; solar constant, 225

Arago, eclipse of 1842 62, 64, 65; prominences, 69 polarization in comets, 103 magnetic relations of auroræ, 130 nature of photosphere, 151 meteor-systems, 329

Arai, photographs of corona of 1887 185

Arcturus, spectrum, 373 383; radial movement, 387

Argelander, Bonn Durchmusterung, 32, 423; solar motion, 39 centre of Milky Way, 40 comet of 1811 100

Aristotle, description of a comet, 350

Arrhenius, light-pressure theory of comets, 348

Asten, movements of Encke's comet, 94

Asteroids, so designated by Herschel, 75

Astronomical circles, 121 122

Astronomical physics, 7,141 142

Astronomical Society founded, 6; Herschel its first President, 14

Astronomy, classification, 1; popularity and progress, 5 in United States, 6 in Germany, 28 practical reform, 32 of the invisible, 42 physical, 141

Atmosphere, solar, 94, 182 192 221 225; of Venus, 236 239 253 254 of Mercury, 246-248 of the moon, 263 264 of Mars, 276 of minor planets, 288

Auroræ, periodicity, 129 162; excited by meteors, 335

Auwers, reduction of Bradley's observations, 39; system of Procyon, 42 opposition of Victoria, 238 solar parallax, 240 new star in Scorpio, 395

Babinet, nebular hypothesis, 314

Backlund, movements of Encke's comet, 94, 360

Baden-Powell, Sir George, eclipse expedition, 188

Bailey, nebulosity round Pleiades, 411; stellar photometric observations, 421 discovery of variable clusters, 436

Baily, early life and career, 59-61; observations of eclipses, 61-64 density of the earth, 60, 261

Baily's Beads, 61, 62

Bakhuyzen, rotation of Mars, 275

Ball, Sir Robert, parallaxes of stars, 36 note, 416; contacts in transits, 239

Balmer's Law, 198 383

Barnard, micrometrical measures of Neptune, 84; of minor planets, 288 of Saturn's rings, 301 photographs of solar corona, 186 190 transit of Mercury, 245 halo round Venus, 254 surface of Mars, 280 ellipticity of Jupiter's first satellite, 292 of Uranus, 304 discovery of inner Jovian satellite, 293 434 red spot on Jupiter, 296 eclipse of Japetus, 300 attendants on comet of 1882 363 on Brooks's comet, 366 367 Swift's comet, 368 photographic discovery of a comet, 369 observations of Nova Aurigæ, 398 399 Hind's variable nebula, 403 exterior Pleiades nebulosities, 411 galactic stars, 423 photographs of Milky Way, 424 425 cluster variables, 433 horizontal telescope, 438

Bartlett, photograph of a partial eclipse, 166

Basic lines, 206 207

Baxendell, meteors of 1866 331

Becker, drawings of solar spectrum, 211

Beckett, Sir E. (Lord Grimthorpe), value of solar parallax, 232

Beer and Mädler, surveys of lunar surface, 265 267; studies of Mars, 275

Bélopolsky, coronal photographs, 185; theory of corona, 191 rotation of Venus, 252 of Jupiter, 297 spectroscopic determinations of Saturn's rings, 300 spectrum of γ Cassiopeiæ, 378 system of Castor, 389 391 detection of variable stars as spectroscopic binaries, 391

Berberich, mass of asteroids, 287; orbit of Holmes's comet, 337

Berkowski, daguerrotype of eclipsed sun, 166

Bessel, biographical sketch, 28-30; reduction of Bradley's observations, 32 parallax of 61 Cygni, 36 disturbed motion of Sirius and Procyon, 41 trans-Uranian planet, 79 Halley's comet, 102 theory of instrumental errors, 122 personal equation, 123 rotation of Mercury, 246 lunar atmosphere, 263 cometary emanations, 325 345 multiple tails, 347 comet of 1807 352

Betelgeux, remoteness, 37, 417; spectrum, 373 381 383 384 radial movement, 387

Bianchini, rotation of Venus, 250

Biela, discovery of a comet, 95

Bigelow, magnetic and solar disturbances, 161; theory of corona, 191

Bigourdan, eclipse of 1893 187; velocity of comet of 1882 364

Bird's quadrants, 4,112 121

Birmingham, colours of stars, 375 note; discovery of T Coronæ, 393

Birt, rotation of a sun-spot, 144; Selenographical Society, 266

Bischoffsheim, Coudé telescope, 436

Black Ligament, 235

Bode, popular writings, 5; solar constitution, 57 missing planet, 72, 73

Bode's Law, 71, 83, 286

Boeddicker, heat-phases during lunar eclipses, 269 270; drawings of Jupiter, 296 of the Milky Way, 424

Boehm, solar observations, 146 148

Boguslawski, centre of sidereal revolutions, 41; observation of Halley's comet, 102

Bolometer, principle of construction, 222

Bond, G. P., his father's successor, 86; light of Jupiter, 289 Saturn's rings, 298 Donati's comet, 324 325 Andromeda nebula, 409 double-star photography, 409

Bond, W. C., observation of Neptune's satellite, 84; discovery of Hyperion, 85 of Saturn's dusky ring, 86 resolution of nebulæ, 119 celestial photography, 153 409 satellite-transit on Jupiter, 291

Borda, repeating circle, 121

Boss, solar translation, 40; observations on comets, 352 356

Bossert, proper motions of stars, 415

Bouguer, solar atmospheric absorption, 221

Boulliaud, period of Mira, 10

Bouvard, tables of Uranus, 78; Encke's comet, 90

Boys, radio-micrometer, 220; density of the earth, 261

Bradley, discoveries of aberration and nutation, 3; solar translation, 10 star-distances, 10, 16 observation observation on Castor, 17 instruments, 28, 120 observations reduced by Bessel and Auwers, 32, 39

Brahe, Tycho, star of 1572 24

Brandes, observations of meteors, 327 334;

Braun, prominence photography, 197; density of the earth, 261

Brayley, meteoric origin of planets, 311

Brédikhine, theory of cometary appendages, 100 348; repulsive forces, 346 347 chemical differences, 347 348 formative types, 351 352 355 363 369 structure of chromosphere, 199 red spot on Jupiter, 294 Andromede meteors, 337 stationary radiants, 341 spectrum of Coggia's comet, 343

Bremiker, star maps, 81

Brenner, rotation of Venus, 252

Brester, Théorie du Soleil, 152

Brewster, diffraction theory of corona, 67; telluric lines in solar spectrum, 134 absorption spectra, 136

Brinkley, ostensible stellar parallaxes, 33

Brisbane, establishment of Paramatta Observatory, 6, 90

Brooks, fragment of 1882 comet, 363; cometary discoveries, 365 366

Brünnow, stellar parallaxes, 113 416

Bruno, Giordano, motion of stars, 9

Buffham, rotation of Uranus, 303

Buffon, internal heat of Jupiter, 289

Bunsen, discovery of spectrum analysis, 132

Burchell, magnitude of η Carinæ, 48

Burnham, stellar orbits, 46; coronal photographs, 186 measures of Nova Aurigæ, 399 of planetary nebulæ, 404 discoveries of double stars, 418 430 433 435 catalogue, 419 system of 61 Cygni, 419

Burton, canals of Mars, 279; rotation of Jupiter's satellites, 292

Calandrelli, stellar parallaxes, 33

Callandreau, capture theory of comets, 98

Campani, Saturn's dusky ring, 86

Campbell, Lieutenant, polarisation of corona, 170

Campbell, Professor, stellar radial velocities, 39, 406 434; flash spectrum, 189 spectroscopic observations of Saturn's rings, 300 Wolf-Rayet stars, 380 spectroscopic binaries, 389 Nova Aurigæ, 398 translation of solar system, 406 stellar diffraction-spectra, 440

Canals of Mars, 278-280

Cannon, Miss A. J., spectrographic researches, 386

Canopus, remoteness, 37, 417; spectrum, 416

Capella, spectrum, 373 383 384; a spectroscopic binary, 389

Carbon, material of photosphere, 152; absorption by, in sun, 212 in stars, 374

Carbonelle, origin of meteorites, 340

Carinæ, η, light variation, 48, 49; spectrum, 379

Carrington, astronomical career, 144 145; sun-spot observations, 146 solar rotation, 147 spot-distribution, 148 luminous outburst on sun, 159 160 Jovian and sun-spot periods, 163 origin of comets, 370

Cassini, Domenico, discoveries of Saturnian satellites, 84; of division in ring, 85 solar rotation period, 146 solar parallax, 228 rotation of Venus, 250 of Mars, 274 of Jupiter, 290 295 satellite of Venus, 256 satellite-transit on Jupiter, 291

Cassini, J. J., stellar proper motions, 10; sun-spots on limb, 54 theory of corona, 66 rotation of Venus, 250 structure of Saturn's rings, 299

Castor, system of, 18, 389

Cavendish experiment, 60, 261

Ceres, discovery, 73, 74; diameter, 75, 288

Chacornac, observation of sun-spot, 156; star-maps, 284 413 variable nebula, 403

Challis, search for Neptune, 81, 82; duplication of Biela's comet, 96

Charlois, discoveries of minor planets, 283

Charroppin, coronal photographs, 186

Chase, photographic discovery of a comet, 338; stellar parallaxes, 416

Chladni, origin of meteors, 327 332

Christie, Mercurian halo, 245

Chromosphere, early indications, 68; distinct recognition, 69, 70, 167 depth, 174 175 200 metallic injections, 195 eruptive character, 199 spectrum, 200

Clark, Alvan, large refractors, 114 429 430 436

Clark, Alvan G., discovery of Sirian companion, 42, 430; 40-inch refractor, 433

Clarke, Colonel, figure of the earth, 262

Clarke, F. W., celestial dissociation, 206

Clausen, period of 1843 comet, 105; cometary systems, 362

Clerihew, secondary tail of 1843 comet, 103

Clusters, variable stars in, 436

Coggia, discovery of a comet, 343

Comet, Halley's, return in 1759 4, 88; orbit computed by Bessel, 29 capture by Neptune, 98, 365 return in 1835 101-103 345 type of tail, 346 352 of 1843 7,103-105 type of tail, 346 352 relationships, 349-351 Newton's, 88, 364 Encke's, 90 changes of volume, 92 of brightness, 95 acceleration, 93, 94 capture by Mercury, 99 Winnecke's, 94, 342 Biela's, 95-97, 333 Brorsen's, 97 Vico's, 97, 367 Faye's, 98 of 1811 99-101 346 of 1807 100 347 352 of 1819 101 103 Lexell's, 106 367 Tewfik, 178 358 362 369 Donati's, 323-325 347 348 of 1861 326 327 346 Perseid, 327 332 Leonid, 327 332 333 343 Klinkerfues's, 335 Holmes's, 337 343 369 Coggia's, 343 346 347 of 1901 343 of 1880 349 351 Aristotle's, 350 Tebbutt's, 352-355 Schaeberle's, 355 356 Wells's, 356 357 of September, 1882 358-361 362-364 Thome's, 361 Pons-Brooks, 365 366 Sawerthal's, 366 Brooks's, of 1889 366 367 Swift's, 368

Cometary tails, repulsive action upon, 100 103 104 346-348; coruscations in, 105 three types, 346-348 355 363 multiple, 347 348 351 352 355 363 368

Comets, subject to gravitation, 88; of short period, 92, 93 translucency, 95, 105 106 353 small masses, 96, 106 capture by planets, 98, 306 367 changes of volume, 102 365 369 polarisation of light, 103 354 355 refractive inertness, 106 353 relations to meteor-systems, 327 332-336 disintegration, 333 339 362 363 spectra, 342-344 354 355 362-364 luminous by electricity, 344 355 357 systems, 353 355 357 362 365 origin, 369-371

Common, reflectors for eclipse photography, 187; Jupiter's inner satellite, 293 detection of great comet near the sun, 358 its five nuclei, 362 photographs of Andromeda nebula, 395 of Orion nebula and Jupiter, 407 408 great reflectors, 412 429 cluster variables, 436

Common, Miss, drawing of eclipsed sun, 187

Comstock, lunar atmosphere, 264

Comte, celestial chemistry, 140; astronomy, 142

Cooke, 25-inch refractor, 430

Copeland, comets of 1843 and 1880 349; spectrum of comet of 1882 364 of γ Cassiopeiæ, 378 of Nova Andromedæ, 395; of Orion nebula, 407 discoveries of gaseous stars, 379 Nova Aurigæ, 396 398

Copernicus, stellar parallax, 16

Cornu, telluric lines in solar spectrum, 202; velocities in prominences, 205 ultra-violet solar spectrum, 210 215 velocity of light, 232 note, 241 spectrum of hydrogen, 383 of Nova Cygni, 393

Cornu and Bailie, density of the earth, 261

Corona of 1842 62-64, 67; early records and theories, 65-67 photographs, 166 173 178 181 185-190 spectrum, 170 173 178 188 190 193 varying types, 174-176 193 of 1877 175-177 of 1882 177 of 1869 183 of 1886 185 of 1889 185-187 of 1893 188 of 1898 189 of 1900 189 of 1901 190 daylight photography of, 179-180 glare theory, 182 mechanical theory, 191 electro-magnetic theories, 191 192

Coronium, 171 174 193

Cortie, movements in sun-spots, 157; their spectral changes, 208

Cotes, corona of 1715 176

Croll, secular changes of climate, 259 260; derivation of solar energy, 313

Crookes, chemical elements, 210

Crova, solar constant, 225

Cruls, comet of 1882 358 364

Cusa, solar constitution, 57

Cysatus, Orion nebula, 21; comet of 1618 362

Damoiseau, theory of Halley's comet, 101

D'Arrest, orbits of minor planets, 285; Andromede meteors, 334 ages of stars, 375 variable nebulæ, 403 measures of nebulæ, 404

Darwin, G. H., rigidity of the earth, 258; Saturn's ring system, 301 origin of the moon, 316-318 development of solar system, 318 319 322 solar tidal friction, 319

Daubrée, falls of aerolites, 339

Davidson, satellite-transit on Jupiter, 292

Davis, stellar parallaxes, 417

Dawes, prominences in 1851 70; Saturn's dusky ring, 86 a star behind a comet, 106 solar observations, 143 164 observations and drawings of Mars, 276 278 280 satellite-transits on Jupiter, 291 292

De Ball, markings on Mercury, 248

Delambre, Greenwich observations, 3; solar rotation, 146 light-equation, 231

De la Roche, Newton's law of cooling, 217

De la Rue, celestial photography, 152 153 268; solar investigations, 154 expedition to Spain, 166 167

De la Tour, experiments on liquefaction, 151

Delaunay, tidal friction, 271 272; Coudé telescope, 436

Delisle, diffraction theory of corona, 67; transits of Venus, 233 239

Dembowski, double star measurements, 418

Denning, observations of Mercury, 246 247; mountain on Venus, 253 rotation of Jupiter, 290 red spot, 295 periodicity of markings, 297 rotation of Saturn, 302 meteors of 1885 336 of 1892 338 stationary radiants, 341

Denza, meteors of 1872 334

Derham, theory of sun-spots, 53; ashen light on Venus, 255

Deslandres, eclipse expedition, 187; rotation of corona, 188 prominence photography, 198 hydrogen spectrum in prominences, 198 383 photographs of Jupiter, 297 radial movements of Saturn's rings, 300 helium absorption in stars, 376 stellar radial velocities, 406

Diffraction, corona explained by, 67, 70, 181; spectrum, 139 210 223 439

Dissociation in the sun, 152 206-210; in space, 312

Doberck, orbits of double stars, 38, 418

Dollond, discovery of achromatic telescope, 4,112

Donati, discovery of comet, 323; spectra of comets, 342 of stars, 372

Doppler, effect of motion on light, 200

Douglass, observations of Jupiter's satellites, 292

Downing, perturbations of the Leonids, 338

Draper, H., ultra-violet spectrum, 210; oxygen in sun, 213 photographs of the moon, 268 of Jupiter's spectrum, 291 of Tebbutt's comet, 354 of spectrum of Vega, 382 of Orion nebula 407

Draper, J. W., lunar photographs, 152; distribution of energy in spectrum, 223 note

Draper Memorial, 384-386

Dreyer, Catalogue of Nebulæ, 50

Dulong and Petit, law of radiation, 217 219

Dunér, spectra of sun-spots, 156; spectroscopic measurement of solar rotation, 203 spectroscopic star catalogue, 381

Dunkin, solar translation, 39

Duponchel, sun-spot period, 163

Durchmusterung, Bonn, 33, 412; Cape photographic, 412 parallax, 418 photometric, 421

Dyson, coronal photographs, 190

Earth, mean density, 60, 261; knowledge regarding, 257 rigidity, 257 259 variation of latitude, 258 259 figure, 261 262 effects of tidal friction, 271-273 bodily tides, 316 primitive disruption, 317

Easton, structure of Milky Way, 423 424

Ebert, coronoidal discharges, 192

Eclipse, solar, of 1836 61; of 1842 62-65, 67, 69 of 1851 69, 70, 166 of 1860 166 167 of 1868 167-170 of 1869 170 of 1870 171 of 1871 173 of 1878 174-177 of 1882 177 178 of 1883 180 181 of 1885 183 of 1886 184 of 1887 185 of 1889 185-187 of 1893 187 188 of 1896 188 of 1898 189 of 1900 189 190 of 1901 190

Eclipses, lunar, heat-phases during, 269 270

Eclipses, solar, importance, 59; ancient, 60, 273 classification, 61 results, 192 193

Eddie, comet of 1880 349; of 1882 363

Edison, tasimeter, 177

Egoroff, telluric lines in solar spectrum, 211 214

Elements, chemical, dissociation in sun, 206 209 210

Elkin, star parallaxes, 37, 416 417; photography of meteors, 338 transit of great comet, 358 360 secondary tail, 363 triangulation of the Pleiades, 410

Elliot, opinions regarding the sun, 57

Elvins, red spot on Jupiter, 296

Encke, star maps, 78; calculation of short-period comet, 90 resisting medium, 93 distance of the sun, 230 232 period of Pons's comet, 365

Engelmann, rotation of Jupiter's satellites, 292

Ericsson, solar temperature, 218

Erman, meteoric rings, 330

Eros, measures of, for solar parallax, 238; discovery, 284 variability, 285

Ertborn, mountain in Venus, 253

Espin, spectra of variable stars, 379; stars with banded spectra, 381 Nova Aurigæ, 397 398

Euler, resisting medium, 93

Evershed, eclipse photographs, 189 200

Evolution, of solar system, 308 309 313-316 322; of earth-moon system, 316-318 of stellar systems, 420

Fabricius, David, discovery of Mira Ceti, 10

Fabricius, John, detection of sun-spots, 52

Faculæ, relation to spots, 53, 155 158; solar rotation from, 155 photographed, 197 198 377

Faye, nature of prominences, 70, 166; discovery of a comet, 98 cyclonic theory of sun-spots, 144 157 solar constitution, 150-152 maximum of 1883 163 velocities in prominences, 205 distance of the sun, 240 planetary evolution, 314 315 321

Feilitsch, solar appendages, 70

Fényi, solar observations, 184 204

Ferrel, tidal friction, 272

Ferrer, nature of corona, 67; prominences, 69

Fessenden, electrical theory of comets, 348

Finlay, transit of great comet, 358 360

Fizeau, daguerrotype of the sun, 153; Doppler's principle, 201 velocity of light, 232

Flammarion, canals of Mars, 280; trans-Neptunian planet, 306

Flamsteed, solar constitution, 57; distance, 228

Flaugergues, detection of 1811 comet, 99; transit of Mercury, 244

Fleming, Mrs., spectrum of β Lyræ, 379; preparation of Draper Catalogue, 386 discoveries of new stars, 399

Flint, star-parallaxes, 417

Fontana, mountains of Venus, 252; satellite, 256 spots on Mars, 274

Forbes, George, trans-Neptunian planets, 306 307

Forbes, James D., spectrum of annularly eclipsed sun, 134; solar constant, 225

Foucault, spectrum of voltaic arc, 137; photograph of the sun, 153 velocity of light, 232 240 silvered glass reflectors, 429

Fraunhofer, early accident, 33; improvement of refractors, 34 clockwork motion, 121 spectra of flames, 131 of sun and stars, 133 134 372 objective prism, 385 diffraction gratings, 439

Fraunhofer lines, mapped, 133 136; origin, 135-137 171 172 reflected in coronal spectrum, 170 173 181 in cometary spectra, 354 357 shifted by radial motion, 201

Freycinet, distribution of minor planets, 287

Fritz, auroral periodicity, 162

Frost, solar heat radiation, 222

Galileo, descriptive astronomy, 2; double-star method of parallaxes, 16 discovery of sun-spots, 52 solar rotation, 146 planets and sun-spots, 163 darkening at sun's edge, 221

Galle, discovery of Neptune, 81, 82; Saturn's dusky ring, 86 distance of the sun, 237 path of Andromede meteors, 334

Galloway, solar translation, 39

Gambart, discovery of comet, 95

Gauss, orbits of minor planets, 74; Theoria Motus, 77 magnetic observations, 126 127 cometary orbits, 370

Gautier, sun-spot and magnetic periods, 126 128; sun-spots and weather, 129

German Astronomical Society, 6,414

Gill, star-parallaxes, 37, 42, 416 417; expedition to Ascension, 237 distance of the sun, 237 238 240 constant of aberration, 241 arc measurements, 261 262 comet of 1882 359 412 oxygen-absorption in stars, 384 photograph of Argo nebula, 404 Cape Durchmusterung, 412 photographic celestial survey, 413 actinic intensity of galactic stars, 425 Coudé telescope, 438

Gladstone, J. H., spectrum analysis, 134 136

Glaisher, occultation by Halley's comet, 106

Glasenapp, coronal photographs, 185; light equation, 231 241 double star measures, 419

Glass, optical, excise duty on, 112 115; Guinand's, 113 114 Jena, 431

Gledhill, spot on Jupiter, 294

Goldschmidt, nebulæ in the Pleiades, 411

Goodricke, periodicity of Algol, 390

Gore, catalogue of variable stars, 391; of computed binaries, 418

Gothard, bright-line stellar spectra, 378 379; spectrum of Nova Aurigæ, 398 photographs of nebulæ, 409

Gould, variation of latitude, 258; photograph of Mars, 281 comets of 1807 and 1881 349 352 luminous instability of stars, 392 photographic measures of the Pleiades, 410 Uranometria Argentina, 415 solar cluster, 423 426

Graham, discovery of Metis, 77

Grant, solar envelope, 70, 167; transit phenomena, 254

Green, observation of Mars, 280

Greenwich observations, 3, 27, 32

Gregory, David, achromatic lenses, 112 note

Gregory, James, double star method of parallaxes, 16; reflecting telescopes, 109

Groombridge, star catalogue, 31

Grosch, corona of 1867 176

Grubb, Sir Howard, photographic reflector, 409; great refractors, 430 433 siderostat, 437

Grubb, Thomas, Melbourne reflector, 110 note, 428

Gruithuisen, snow-caps of Venus, 255; lunar inhabitants, 265

Gully, detection of Nova Andromedæ, 394

Guthrie, nebulous glow round Venus, 253

Hadley, Saturn's dusky ring, 86; reflecting telescope, 109

Haerdtl, Winnecke's comet, 94

Hale, luminous outburst on sun, 161; daylight coronal photography, 179 spectrum of prominences, 195 198 prominence photography, 197 198 photographs of faculæ, 198 377 carbon in chromosphere, 200 bright lines in fourth-type stars, 381 reflectors and refractors, 432

Hall, Asaph, parallax of the sun, 241; discovery of Martian satellites, 282 rotation of Saturn, 302 double star measurements, 419

Hall, Chester More, invention of achromatic telescope, 112

Hall, Maxwell, rotation of Neptune, 305

Halley, stellar proper motions, 9; composition of nebulæ, 22 observation of η Carinæ, 48 eclipse of 1715 66, 68 predicted return of comet, 88 magnetic theory of auroræ, 130 transits of Venus, 233 lunar acceleration, 271 origin of meteors, 327

Halm, magnetic relations of latitude variation, 259

Hansen, solar parallax from lunar theory, 230

Hansky, coronal photographs, 188 189

Harding, discovery of Juno, 75; celestial atlas, 77

Harkness, spectrum of corona, 170; corona of 1878 175 shadow of the moon in solar eclipses, 182 light equation, 231 distance of the sun, 237 240 241 242

Harriot, observations on Halley's comet, 29

Hartley, gallium in the sun, 200 213

Hartwig, Nova Andromedæ, 394

Hasselberg, metallic spectra, 211; spectra of comets, 342 357 of Nova Andromedæ, 395

Hastings, composition of photosphere, 152; observations at Caroline Island, 181 Saturn's dusky ring, 299

Hegel, number of the planets, 73

Heis, radiant of Andromedes, 334

Heliometer, 34, 234 237 238 240

Helium, a constituent of prominences, 194 195 199; no absorption by, in solar spectrum, 213 absorptive action in first-type stars, 376 bright in gaseous stars, 377 378 380 in Orion nebula, 407

Helmholtz, gravitational theory of sun-heat, 311-313

Hencke, discoveries of minor planets, 76

Henderson, parallax of α Centauri, 36, 416; observation of chromosphere, 68

Henry, Paul and Prosper, lunar twilight, 264; markings on Uranus, 303 photograph of Saturn, 408 photographs of nebulæ in the Pleiades, 410 411 stellar photography, 413 plane mirrors, 438

Herrick and Bradley, duplication of Biela's comet, 96

Herschel, Alexander S., cometary and meteoric orbits, 332

Herschel, Caroline, her brother's assistant, 12; observation of Encke's comet, 90

Herschel, Colonel, spectrum of prominences, 168; of reversing layer, 172 of corona, 174

Herschel, Sir John, life and work, 45-50; Magellanic clouds, 47, 422 sun-spots, 58, 59, 144 solar flames, 68 anticipation of Neptune's discovery, 81 status of Hyperion, 85 Biela's comet, 95 Halley's, 102 comet of 1843 103 sixth star in "trapezium," 113 grinding of specula, 116 spectrum analysis, 136 solar photography, 145 154 solar constitution, 151 shadow round eclipsed sun, 182 actinometrical experiments, 216 solar heat, 217 climate and eccentricity, 259 lunar atmosphere, 263 surface of Mars, 276 Andromeda nebula, 396 observations of nebulæ, 404 double nebulæ, 412

Herschel, Sir William, discovery of Uranus, 5; founder of sidereal astronomy, 9 biographical sketch, 11-14 sun's motion in space, 15, 39, 425 revolutions of double stars, 18, 442 structure of Milky Way, 19-21, 423 nature of nebulæ, 21-26, 401 results of his observations, 25 centre of sidereal system, 40 theory of the sun, 54-56, 70 asteroids, 75 discoveries of Saturnian and Uranian satellites, 84, 87, 110 comet of 1811 99 reflecting telescopes, 109-111 sun-spots and weather, 129 transit of Mercury, 244 refraction in Venus, 252 lunar volcanoes, 266 terrestrial affinity of Mars, 274 Jovian trade-winds, 289 rotation of Jupiter's satellites, 292 ring of Saturn, 298 rotation of Saturn, 302 origin of comets, 369 stellar photometry, 420

Herz, comets' tails, 348

Hevelius, "Mira" Ceti, 10; contraction of comets, 92 granular structure of comet, 362

Higgs, photographs of solar spectrum, 211 214

Hind, solar flames, 70; Iris and Flora discovered by, 77 distortion of Biela's comet, 96 transit of a comet, 101 earth in a comet's tail, 326 comets of 1843 and 1880 349 Schmidt's comet, 363 new star, 392 variable nebula, 403

Hirn, solar temperature, 220; resistance in space, 348

Hodgson, outburst on the sun, 160

Hoeffler, star-drift in Ursa Major, 426

Hoek, cometary systems, 362

Holden, Uranian satellites, 87; eclipse expedition, 180 coronal extensions, 186 solar rotation, 203 transit of Mercury, 245 intra-Mercurian planets, 250 drawing of Venus, 252 lunar photographs, 268 canals on Mars, 279 surface of Mars, 281 transits of Jupiter's satellites, 292 markings on Uranus, 304 disintegration of comet, 362 colours of double stars, 374 Nova Aurigæ, 398 Orion and Trifid nebulæ, 403 404 director of Lick Observatory, 435

Holden and Schaeberle, observations of nebulæ, 433

Holmes, discovery of a comet, 337

Homann, solar translation, 406

Hooke, solar translation, 10; stellar parallax, 16 repulsive action on comets, 102 note automatic movement of telescopes, 120 spots on Mars, 274 275

Hopkins, solidity of the earth, 257

Horrebow, sun-spot periodicity, 125; satellite of Venus, 256

Hough, G. W., red spot on Jupiter, 295 430; observations of double stars, 419

Houzeau, solar parallax, 240

Howlett, sun-spot observations, 155

Hubbard, period of comet of 1843 105 351

Huggins, Sir William, spectroscopic observations of prominences, 170 195 hydrogen spectrum in stars, 178 198 daylight coronal photography, 178 179 repulsive action in corona, 191 stellar motions in line of sight, 201 386 387 transit of Mercury, 245 occultation of a star, 263 snowcaps on Mars, 276 spectrum of Mars, 277 of Jupiter, 290 Jovian markings and sun-spots, 297 spectrum of Uranus, 304 of comets, 342 343 photographs, 354 357 stellar spectroscopy, 373 colours of stars, 374 classification of star spectra, 376 photographs, 382 383 438 stellar chemistry, 381 382 spectra of new stars, 393 395 theory of Nova Aurigæ, 397 spectra of nebulæ, 401 402 407 nebular radial movement, 405

Huggins, Sir William and Lady, photograph of Uranian spectrum, 305; spectra of Wolf-Rayet stars, 380 ultra-violet spectrum of Sirius, 383 nitrogen in stars, 384 spectrum of Nova Aurigæ, 396-398 of Andromeda nebula, 403 of Orion nebula, 407

Humboldt, sun-spot period, 126; magnetic observations, 127 meteoric shower, 329

Hussey, T. J., search for Neptune, 79

Hussey, W. J., cloud effects on Mars, 281; cometary appendages, 369 period of δ Equulei, 419 discoveries of double stars, 419 433

Huygens, stellar parallax, 16; Orion nebula, 22 discovery of Titan, 84 Saturn's ring, 85, 301 spot on Mars, 275

Hydrogen, a constituent of prominences, 168 195 199; spectrum, 178 198 383 384 absorption in stars, 198 373 381-383 in sun, 211 theoretical material of comets' tails, 347 emissions in stars, 377-380 384 393 397 in nebulæ, 402 407

Innes, Southern double stars, 419

Jacoby, measurement of Rutherfurd's plates, 410; Pritchard's parallax work, 417

Janssen, photographs of the sun, 165; spectroscopic observations of prominences, 168 169 escape from Paris in a balloon, 171 coronal spectrum, 173 181 coronal photographs, 181 rarefaction of chromospheric gases, 182 oxygen absorption in solar spectrum, 214 transit of 1874 234 spectrum of Venus, 254 of Saturn, 303 photographs of Tebbutt's comet, 353 354 of Orion nebula, 407

Japetus, eclipse of, 300; variability in light, 302

Jewell, solar spectroscopy, 200 211

Joule, heat and motion, 309

Jupiter, mass corrected, 77, 92; conjectured influence on sun-spot development, 163 physical condition, 289 290 spectrum, 290 291 satellite-transits, 291 292 discovery of inner satellite, 293 red spot, 293-296 photographs, 297 408 periodicity of markings, 297

Kaiser, rotation of Mars, 275; map of Mars, 278

Kammermann, observation of Maia nebula, 410

Kant, status of nebulæ, 14; Sirius the central sun, 40 planetary intervals, 71 tidal friction, 272 condition of Jupiter, 289 cosmogony, 308

Kapteyn, solar translation, 40; Cape Durchmusterung, 412 stellar parallaxes, 417 418 actinic intensity of galactic stars, 425 solar cluster, 426

Kayser and Runge, spectroscopic investigations, 211 213

Keeler, red spot on Jupiter, 296; spectroscopic determination of movements in Saturn's rings, 300 spectrum of Uranus, 304 of third type stars, 382 of nebulæ, 402 photographs of nebulæ, 403 411 412 432 nebular radial movements, 405 434 440 grating spectroscope, 440

Kepler, star of 1604 25; solar corona, 66 missing planets, 71 cometary decay, 91, 339 comet of 1618 96 physical astronomy, 141

Kiaer, comets' tails, 348

Kirchhoff, foundation of spectrum analysis, 132 135-137 372; map of solar spectrum, 137 solar constitution, 149 151 172

Kirkwood, distribution of minor planets, 286; grouped orbits, 287 divisions in Saturn's rings, 301 302 origin of planets, 314 their mode of rotation, 321 comets and meteors, 333 339

Kleiber, Perseid radiants, 341

Klein, Hyginus N., 267 268

Klinkerfues, comet predicted by, 335 339; apparitions of Southern comet, 350 tidal theory of new stars, 397

Knobel, cloud effects on Mars, 281

Konkoly, spectrum of γ Cassiopeiæ, 378; spectroscopic survey, 381 note

Kreil, lunar magnetic action, 130

Kreutz, period of 1843 comet, 105; orbit of 1861 comet, 327 period of great September comet, 361 cause of disintegration, 363 eclipse-comet of 1882 362

Krüger, segmentation of great comet, 362

Küstner, variation of latitude, 258

Kunowsky, spots on Mars, 275

Lacaille, southern nebulæ, 22; η Carinæ, 48

Lagrange, theory of solar system, 2; planetary disruption, 76

Lahire, diffraction theory of corona, 67; distance of the sun, 228 mountains of Venus, 252

Lalande, popularisation of astronomy, 5; revolving stars, 18 Histoire Céleste, 31, 415 nature of sun-spots, 53 observations of Neptune, 83

Lambert, solar motion, 10; construction construction of the universe, 14, 40 missing planets, 71

Lamont, magnetic period, 127 128

Lamp, ashen light on Venus, 256

Langdon, mountains of Venus, 253

Langley, solar granules, 165; corona of 1878 176 spectroscopic effects of solar rotation, 202 infra-red spectrum, 210 223 224 experiments at Pittsburg, 221 bolometer, 222 distribution of energy in spectrum, 224 225 atmospheric absorption, 224 225 276 solar constant, 225 lunar heat-spectrum, 269 temperature of lunar surface, 270 age of the sun, 312

Laplace, lunar acceleration, 2,271; Système du Monde, 5 nebular hypothesis, 25, 308 309 313 314 322 stability of Saturn's rings, 85, 298 solar atmosphere, 94, 221 Lexell's comet, 106 367 solar distance by lunar theory, 230 origin of meteors, 328 of comets, 370

Lassell, discovery of Neptune's satellite, 83; of Hyperion, 85 Saturn's dusky ring, 86 observations at Malta, 87, 434 reflectors, 114 equatoreal mounting, 121

Latitude, variation of, 258 259

Laugier, period of 1843 comet, 105; solar rotation, 146

Le Chatelier, temperature of the sun, 219

Lescarbault, pseudo-discovery of Vulcan, 248; halo round Venus, 254

Lespiault, orbits of minor planets, 285

Le Sueur, spectrum of Jupiter, 291

Leverrier, discovery of Neptune, 80-82; Lexell's comet, 98, 367 distance of the sun, 230 240 revolutions of Mercury, 248 supposed transits of Vulcan, 249 mass of asteroids, 287 orbit of November meteors, 332 Perseids and Leonids, 333

Lexell, comet of 1770 98, 106 367

Liais, supposed transit of Vulcan, 249; comet of 1861 326 division of a comet, 339

Librations, of Mercury, 247; of Venus, 251 of the moon, 266

Lick, foundation of observatory, 434

Light, velocity, 38, 232 241; extinction in space, 45 refrangibility changed by movement, 201

Light-equation, 231 241

Ligondès, development of solar system, 316

Lindsay, Lord, expedition to Mauritius, 234

Line of sight, movements in, 201 386; of solar limbs, 202 203 in prominences, 204 208 of stars, 201 386 387 binaries detected by, 387-391

Listing, dimensions of the globe, 262

Littrow, chromosphere, 70; sun-spot periodicity, 126

Liveing and Dewar, carbon in the sun, 212

Lockyer, solar spectroscopy, 156 212; theory of sun-spots, 159 163 daylight observations of prominences, 169 194 204 205 eclipse of 1870 171 slitless spectroscope, 173 corona of 1878 175 glare theory of corona, 182 eclipse of 1886 184 chromospheric spectrum, 195 classification of prominences, 196 their radial movements, 204 celestial dissociation, 206-210 chemistry of sun-spots, 207 spots on Mars, 275 meteoritic hypothesis, 376 402 equatoreal Coudé, 438

Loewy, constant of aberration, 241 438; lunar photographs, 268 director of Paris Observatory, 414 equatoreal Coudé, 436 437

Lohrmann, lunar chart, 265; Linné, 267

Lohse, J. G., spectrum of great comet, 364

Lohse, O., daylight coronal photography, 178 note; spectral investigations, 211 twilight on Venus, 256 red spot on Jupiter, 294 periodicity of Jupiter's markings, 297 motion of Sirius, 386 spectrum of Nova Cygni, 393

Louville, nature of corona, 67; chromosphere, 68

Lowell, rotation of Mercury, 248; of Venus, 252 markings on Venus, 255 observations of Mars, 280 281 satellites, 283

Lyman, atmosphere of Venus, 254

McClean, photographs of solar spectrum, 211 215; helium stars, 377 oxygen stars, 384 equipment of Cape Observatory, 433

Macdonnell, luminous ring round Venus, 254

Maclaurin, eclipse of 1737 65

Maclear, Admiral, observations during eclipses, 172 182

Maclear, Sir Thomas, maximum of η Carinæ, 49; observation of Halley's comet, 102

Mädler, central sun, 41; observations observations of Venus, 253 lunar rills, 263 aspect of Linné, 267 common proper motions, 426

Magellanic clouds, 47, 422; spiral character, 425

Magnetism, terrestrial, international observations, 126; periodicity, 127 128 solar relations, 128 160 161 163 205 lunar influence, 130

Mann, last observation of Donati's comet, 325

Maraldi, solar corona, 67; rotation of Mars, 274 satellite-transits on Jupiter, 291 spot on Jupiter, 295

Marius, Andromeda nebula, 21; sun-spots, 52

Mars, oppositions, 228; solar parallax from, 228 237 240 polar spots, 274 276 277 280 281 permanent markings, 274-276 rotation, 274 275 atmosphere, 276 277 climate, 277 278 canals, 278-281 photographs, 281 satellites, 282 283 314 320 321

Marth, revolutions of Neptune's satellite, 305

Maskelyne, components of Castor, 18; Astronomer-Royal, 27 experiment at Schehallien, 261 comets and meteors, 332

Maunder, photographs of corona of 1886 185; comparative massiveness of stars, 375 constitution of nebulæ, 403

Maunder, Mrs., coronal photographs, 189 190

Maury, director of Naval Observatory, 7; duplication of Biela's comet, 96

Maury, Miss A. C., spectrographic investigations, 386; discoveries of spectroscopic binaries, 387 388

Maxwell, J. Clerk, structure of Saturn's rings, 298 300

Mayer, C., star satellites, 17

Mayer, Julius R., tidal friction, 272; meteoric sustentation of sun's heat, 310

Mayer, Tobias, stellar motions, 10; solar translation, 15 repeating circle, 122 solar distance, 230 satellite of Venus, 256 lunar surface, 263

Mazapil meteorite, 340

Meldrum, sun-spots and cyclones, 164

Melloni, lunar heat, 269

Melvill, spectra of flames, 131

Mercury, mass, 92; luminous phenomena during transits, 244 245 spectrum, 245 mountainous conformation, 246 247 rotation, 247 248 theory of movements, 248 250

Mersenne, reflecting telescope, 108

Messier, catalogue of nebulæ, 22

Meteoric hypothesis of solar sustentation, 310; of planetary formation, 311

Meteoritic hypothesis of cosmical constitution, 376 402

Meteors, origin, 327 328; relations to comets, 327 332-334 340 Leonids, 328-334 338 Perseids, 329 332 333 341 Andromedes, 334-338 stationary radiants, 341

Meunier, canals of Mars, 280

Meyer, divisions of Saturn's rings, 302; comet of 1880 351 cometary refraction, 353 comet Tewfik, 362

Michell, double stars, 17; torsion balance, 261 star systems, 426

Michelson, velocity of light, 241

Milky Way, grindstone theory, 14; clustering power, 20, 26 structure, 20, 41, 45, 47, 423-425 centre of gravity, 40, 41 frequented by Wolf-Rayet, temporary, and helium stars, 380 399 425 by gaseous nebulæ, 402 drawings and photographs, 424 425

Miller, W. A., spectrum analysis, 132 136 137; stellar chemistry, 373

Mira, light changes, 10; spectrum, 374 379

Mitchel, lectures at Cincinnati, 6

Mitchell, photograph of reversing layer, 190

Möller, theory of Faye's comet, 98

Mohn, origin of comets, 370

Moll, transit of Mercury, 245

Monck, Perseid meteors, 341; new stars, 395

Moon, acceleration, 2,271 272; magnetic influence, 130 photographs, 152 153 268 solar parallax from disturbed motion, 230 240 study of surface, 263 atmosphere, 263-265 charts, 265-267 librations, 266 superficial changes, 267 268 thermal radiations, 269 270 rotation, 272 tables, 272 273 origin, 316-318

Morinus, celestial chemistry, 140

Morstadt, Andromede meteors, 332

Mouchez, photographic survey of the heavens, 413; death, 414

Müller, phases of Mercury, 246; of minor planets, 288 albedo of Mars, 283 of Jupiter, 290 of Saturn, 303 variability of Neptune, 305 of Pons's comet, 366 stellar photometry, 421

Munich, Optical Institute, 28, 34

Myer, solar eclipse, 183 Myer, solar eclipse, 183

Nasmyth, Lassell's reflector, 83; solar willow-leaves, 164 comparative lustre of Mercury and Venus, 255 condition of Jupiter, 289

Nasmyth and Carpenter, The Moon, 265

Nebula, Andromeda, early observations, 21; new star in, 394 395 photographs, 395 409 structure, 396 spectrum, 402 403 visibility at Arequipa, 435

Nebula, Orion, observed by Herschel, 12; mentioned by Cysatus, 21 apparent resolvability, 119 suspected variability, 403 radial movement, 405 spectrum, 407 photographs, 407 408 436

Nebulæ, first discoveries, 22; catalogues, 22, 46, 50, 412 distribution, 23, 48, 422 composition, 24, 47, 401 402 resolution, 47, 117 119 double, 48, 412 spiral, 118 410 412 new stars in, 394-396 399 401 spectra, 401-403 407 variability, 403 404 radial movements, 405 photographs, 407-409 425

Nebular hypothesis, Herschel's, 24, 25; Laplace's, 25, 308 309 322 objections, 313-315

Neison, atmosphere of Venus, 254; rills on the moon, 263 The Moon, 265

Neptune, discovery, 78-83; satellite, 83, 305 density, 84 comets captured by, 98, 306 365 mode of rotation, 305 313 315 322

Newall, F., duplicity of Capella, 389; stellar radial motions, 430

Newall, R. S., 25-inch refractor, 430

Newcomb, runaway stars, 39; solar translation, 40 origin of minor planets, 76 telescopic powers, 119 corona of 1878 176 of 1869 183 distance of the sun, 231-233 velocity of light, 241 variation of latitude, 259 lunar atmosphere, 263 lunar theory, 272 273 disturbance of Neptune's satellite, 305 formation of planets, 314 star catalogue, 415 structure of Milky Way, 423

Newton, H. A., capture of comets by planets, 98; falls of aerolites, 311 November meteors, 330 331 meteors of 1885 336 337 orbits of aerolites, 340

Newton, Sir Isaac, founder of theoretical astronomy, 1,141; comets subject to gravitation, 88 first speculum, 109 solar radiations, 216 law of cooling, 217-219 telescopes and atmosphere, 434

Niesten, volume of asteroids, 287; red spot on Jupiter, 293

Nobert, diffraction gratings, 439

Noble, observations of Mercury, 246; secondary tail of comet, 355

Nolan, origin of the moon, 317; period of Phobos, 320

Norton, expulsion theory of solar appendages, 193 note; comets' tails, 345 347

Nova Andromedæ, 394 395

Nova Aurigæ, 396-399

Nova Cygni, 393 394 398

Nova Persei, 400 401

Nutation, discovered by Bradley, 3, 15; a uranographical correction, 31

Nyrén, constant of aberration, 241

Observatory, Greenwich, 3, 27, 433; Cape of Good Hope, 6, 36, 433 Paramatta, 6, 90 Harvard College, 7, 85 Königsberg, 30 Dorpat, 43 Pulkowa, 44 Palermo, 72 Berlin, 90 Anclam, 149 Potsdam, 149 Kew, 153 Arequipa, 264 435 436 Yerkes, 433 Lick, 435

Occultations of stars by comets, 95, 105 106; by the moon, 263 by Mars, 276 of Jupiter by the moon, 264

Olbers, Bessel's first patron, 29, 30; discoveries of minor planets, 74, 75 origin by explosion, 75, 76 career, 89, 90 Biela's comet, 95 comet of 1811 99 electrical theory of comets, 100 104 324 347 multiple tails, 100 comet of 1819 101 cometary coruscations, 105 November meteors, 329

Olmsted, radiant of Leonids, 328; orbit, 329

Oppenheim, calculation of Schmidt's comet, 363

Oppolzer, E. von, theory of sun-spots, 159; variability of Eros, 285

Oppolzer, Th. von, Winnecke's comet, 94; comet of 1843 350

Oxygen in sun, 213-215; telluric absorption, 214 in stars, 384

Packer, variable stars in cluster, 436

Palisa, search for Vulcan, 181 250; discoveries of minor planets, 283

Pallas, discovery, 74; inclination of orbit, 75, 286 diameter, 75, 287 288

Pape, Donati's comet, 345

Parallax, annual, of stars, 10, 16, 33, 36, 416-418; horizontal, of sun, 227 Encke's result, 230 232 improved values from oppositions of Mars, 231 237 from light velocity, 231 232 241 from recent transits, 236 240 from observations of minor planets, 238 239 general result, 242

Paris Catalogue of Stars, 415

Paschen, oxygen in sun, 215; solar temperature, 220

Pastorff, drawings of the sun, 101

Peirce, structure of Saturn's rings, 298

Perrine, eclipse photographs, 190; nature of corona, 191 observation of Holmes's comet, 369 nebula round Nova Persei, 401

Perrotin, rotation of Venus, 252; markings on, 255 canals of Mars, 279 clouds on Mars, 281 striation of Saturn's rings, 299 rotation and compression of Uranus, 303 304 changes of Pons's comet, 366 Maia nebula, 410 measures of double stars, 419

Perry, eclipse of December, 1889 187

Personal equation, 123 235

Peter, star-parallaxes, 417

Peters, C. A. F., parallax of 61 Cygni, 36 disturbed motion of Sirius, 42

Peters, C. F. W., orbit of Leonid meteors and comet, 332

Peters, C. H. F., sun-spot observations, 147 148; discoveries of minor planets, 283 star maps, 284 415

Peytal, description of chromosphere, 69

Phobos, rapid revolution, 282 283 314; tidal relations, 320 321

Photography, solar, 145 153 154 165; of corona, 166 173 175 178 181 185-190 without an eclipse, 178-180 of prominences, 167 197 198 of coronal spectrum, 171 188 190 of prominence-spectrum, 195 198 of arc-spectrum, 206 211 of solar spectrum, 210 211 215 439 440 of Uranian spectrum, 305 of cometary spectra, 354 357 of stellar and nebular spectra, 382-384 396 398 400 407 lunar, 152 153 268 detection of comets by, 178 338 369 of asteroids, 284 of new stars, 399 use of, in transits of Venus, 234 236 240 Mars depicted by, 277 281 Jupiter, 297 408 comets, 353 354 368 412 nebulæ, 395 401 407-409 411 425 Milky Way, 424 425 star-charting by, 413 414 star-parallaxes by, 417 rapid improvement, 438

Photometry, stellar, 49, 420 421; of planetary phases, 245 288 of Saturn's rings, 299 photographic, 421

Photosphere, named by Schröter, 55; structure, 151 152 164 165

Piazzi, star catalogues, 31; parallaxes, 33 motion of 61 Cygni, 35 birth and training, 72 5-foot circle, 72, 121 discovery of Ceres, 73, 74

Picard, Saturn's dark ring, 86; sun's distance, 228

Pickering, E. C., photometric measures of Martian satellites, 282; of minor planets, 287 variability of Japetus, 302 of Neptune, 305 meteoric photography, 339 gaseous stars, 379 hydrogen spectrum in stars 383 spectrographic results, 385 eclipses of Algol, 390 photographic celestial surveys, 399 star density in Pleiades, 411 photometric catalogues, 420 421 photographic photometry, 421 white stars in Milky Way, 425 climate of Arequipa, 435 horizontal telescope, 437

Pickering, W. H., corona of 1886 185; coronal photographs, January 1, 1889 186 lunar twilight, 264 lunar volcanic action, 267 melting of snow on Mars, 277 Martian snowfall, 281 Jupiter's satellites, 292 photographs of comets, 368 of Orion nebula, 408 observatory at Arequipa, 435

Pingré, phenomena of comets, 92, 96

Planets, influence on sun-spots, 163; periods and distances, 228 intra-Mercurian, 248-250 inferior and superior, 288 trans-Neptunian, 306 307 origin, 309 313 relative ages, 314 315

Planets, minor, existence inferred, 71, 72; discoveries, 73-75, 77, 283 284 solar parallax from, 237-239 distribution of orbits, 286 287 collective volume, 287 atmospheres, 288

Plantade, halo round Mercury, 244

Pleiades, community of movement near, 41; photographed spectra, 385 measurements, 410 photographs, 410 411 nebulæ, 410 411

Plücker, hydrogen in sun, 212

Plummer, solar translation, 39; Encke's comet, 99

Plutarch, solar corona, 65

Pogson, prominence spectrum, 168; reversing layer, 172 discovery of a comet, 335 339 new star in cluster, 395 new star in cluster, 395

Pond, errors of Greenwich quadrant, 28; controversy with Brinkley, 33

Pons, discoveries of comets, 90, 94, 365

Pontécoulant, return of Halley's comet, 101

Poor, C. Lane, calculation of Lexell's comet, 367

Porter, solar translation, 40

Pouillet, solar constant, 216 225; temperature of the sun, 217 of space, 270

Poynting, mean density of the earth, 261

Prince, glow round Venus, 253

Pritchard, parallax of β Aurigæ, 388; photographic determinations of stellar parallax, 417 photometric catalogue, 420

Pritchett, corona of January, 1889 186; red spot on Jupiter, 294

Proctor, glare theory of corona, 182; speed of ejections from sun, 205 transit of Venus, 233 distance of sun, 236 atmosphere of Venus, 254 rotation of Mars, 275 map and canals of Mars, 278 279 condition of great planets, 289 Nova Andromedæ, 403 status of nebulæ, 422 423 structure of Milky Way, 424 star drift, 426

Procyon, satellite, 42; parallax, 417

Prominences, observed in 1842 63, 64, 68; described by Vassenius, 68 observed in 1851 70 photographed during eclipse, 167 188 190 without eclipse, 197 198 spectrum, 168 178 194 195 198 199 spectroscopic method of observing, 168-170 194-196 white, 183 184 chemistry, 195 199 classification, 196 distribution, 199 movements in, 204-206 heat of development, 220

Quetelet, periodicity of August meteors, 329

Ranyard, drawing of sun-spot, 101; coronal types, 175 185 lunar atmosphere, 265 Jupiter's markings, 297 meteors from fixed radiants, 341 cometary trains, 348 tenuity of nebulæ, 409

Rayet, spectrum of prominences, 168 170

Red spot on Jupiter, 293 296

Reduction of observations, 31; Bessel's improvements, 32, 122 Baily's, 60

Refraction, atmospheric, 31; effects looked for in comets, 106 353 Cytherean, 235 253 254 lunar 263 264

Reichenbach, foundation of Optical Institute, 28, 34, 122

Repsold, astronomical circles, 41, 122; Cape heliometer, 416

Resisting medium, 93, 94, 360

Respighi, slitless spectroscope, 173; prominences and chromosphere, 194 196 199 solar uprushes, 205 spectrum of γ Argûs, 380

Reversing layer, detected, 171 172; photographed, 172 189 depth, 173

Riccioli, secondary light of Venus, 255

Riccò, trials with coronagraph, 180; distribution of prominences, 199 spectrum of Venus, 254 spot on Jupiter, 294 spectrum of great comet, 364

Richer, distance of the sun, 228

Ristenpart, solar translation, 40

Ritchey, nebula round Nova Persei, 401; photographs of nebulæ, 432

Ritter, development of stars, 375

Roberts, A. W., southern variables, 392

Roberts, Isaac, search for ultra-Neptunian planet, 306; photographs of Orion nebula, 408 of Andromeda nebula, 409 of the Pleiades, 411

Roberval, structure of Saturn's rings, 299

Robinson, reflectors and refractors, 431

Roche, inner limit of satellite-formation, 301; modification of nebular hypothesis, 321

Römer, star places, 10; invention of equatoreal and transit instrument, 120 of altazimuth, 121 velocity of light, 231 satellite transit on Jupiter, 291

Rosenberger, return of Halley's comet, 101

Rosetti, temperature of the sun, 219

Rosse, third Earl of, biographical sketch, 114; great specula, 115-117 discovery of spiral nebulæ, 118 resolution of nebulæ, 119 climate and telescopes, 434

Rosse, fourth Earl of, experiments on lunar heat, 269

Rost, nature of sun-spots, 54

Roszel, mass of asteroids, 287

Rowland, photographic maps of solar spectrum, 210 440; elements in run, 213 concave gratings, 439 440

Rümker, observation of Encke's comet, 90

Russell, H. C., red spot on Jupiter, 295; change in Argo nebula, 404 photographs of Nubeculæ, 425 photographs of Nubeculæ, 425

Russell, H. N., atmosphere of Venus, 254

Rutherfurd, lunar photography, 268; star spectra, 372 photographs of the Pleiades, 410 diffraction gratings, 439

Sabine, magnetic and sun-spot periods, 127 128 130

Safarik, secondary light of Venus, 256; compression of Uranus, 304

Satellites, discoveries, 110 282 293; transits, 291 292 variability, 292 302 origin, 309 318

Saturn, low specific gravity, 298; rotation, 302 spectrum, 303

Saturn's rings, first disclosure, 85; dusky ring, 86 stability, 298 300 meteoric constitution, 300 eventual dispersal, 301

Savary, orbits of double stars, 46

Savélieff, solar radiation, 164 225

Sawerthal, discovery of a comet, 366

Schaeberle, discovery of Procyon's satellite, 42; coronal photographs, 187 188 theory of corona, 191 meteoric photography, 339 discovery of a comet, 355

Schaeberle and Campbell, observations of Jupiter's satellites, 292

Scheiner, Father, nature of sun-spots, 52, 54; equatoreal instrument, 120 note solar rotation, 146 darkening of sun's limb, 221

Schiener, Dr. J., photospheric structure, 165; spectrographic researches, 384 405 spectrum of Andromeda nebula, 403 stars and nebulæ in Orion, 407

Schiaparelli, rotation of Mercury, 247; of Venus, 251 252 spots on Mars, 275 snow-cap, 277 canals, 278-280 compression of Uranus, 304 comets and meteors, 327 331 332 338 anomalous tail of great comet, 364 Pons's comet, 365 origin of comets, 370 measures of double stars, 419

Schmidt, A., circular refraction in sun, 159

Schmidt, J., sun-spot period, 126; lunar rills, 263 lunar maps, 265 disappearance of Linné, 267 cometary appendages, 363 new stars, 393

Schönfeld, extension of Bonn Durchmusterung, 412 414

Schrader, construction of reflectors, 243

Schröter, a follower of Herschel, 5; motions of sun-spots, 146 biographical sketch, 243 244 observations on Mercury, 244 246 247 on Venus, 250-253 255 on the moon, 263 a lunar city, 265 Linné, 267 spots on Mars, 275 Jovian markings, 290

Schülen, perspective effects in sun-spots, 54

Schuster, photographs of corona, 178 185; spectra of oxygen, 214

Schwabe, sun-spot periodicity, 125 126

Secchi, chromosphere, 70; Biela's comet, 97 cyclonic movements in sun-spots, 144 distribution, 148 profundity, 154 nature, 156 158 constitution of photosphere, 151 eclipse observations, 166 167 reversing layer, 171 observations of prominences, 194 196 199 absence of helium absorption, 213 temperature of the sun, 218 solar atmospheric absorption, 221 Martian canals, 279 spectrum of Uranus, 304 of Coggia's comet, 343 stellar spectral researches, 372 373 carbon stars, 372 381 gaseous stars, 377

See, stellar orbits, 42, 46; measures of Neptune, 84 measures of Uranus, 304 belts of Neptune, 306 colour of Sirius, 375 note southern double stars, 419 evolution of stellar systems, 420

Seeliger, photometry of Saturn's rings, 299; rationale of new stars, 396

Seidel, stellar photometry, 420

Sherman, spectrum of Nova Andromedæ, 395

Short, reflectors, 4,109 115 121; chromosphere, 68 satellite of Venus, 256 striation of Saturn's rings, 299

Sidereal science, foundation, 9,442; condition in 1785 10 progress, 50

Sidgreaves, spots and faculæ, 159

Siemens, regenerative theory of the sun, 312

Simony, photographs of ultra-violet spectrum, 215

Sirius, a binary star, 41; mass, 42 parallax, 42, 416 spectrum, 133 373 383 former redness, 375 note radial movement, 386 387

Smyth, Admiral, Donati's comet, 324

Smyth, Piazzi, oxygen spectrum, 215; lunar radiations, 269 expedition to Teneriffe, 434

Solar constant, 216 225

Solar spectrum, fixed lines in, 133-135; maps, 133 136 206 210 211 224 440 distribution of energy, 222 223

Solar system, translation through space, 15, 39, 40, 406 development, 308 309 313-316 322 complexity, 441

Soret, solar temperature, 218

South, observations of double stars, 45; 12-inch lens, 113 Rosse reflector, 117 occultation by Mars, 276

Spectroscopic binaries, 387-391

Spectrum analysis, defined, 130; first experiments, 131 132 applied to the sun, 133-135 156 to the stars, 133 372 373 Kirchhoff's theorem, 135 elementary principles, 139 140 effects on science, 141 142 radial motion determined by, 201 386 investigations of comets by, 342 343 of new stars, 393 399 of nebulæ, 401-403

Spencer, position of nebulæ, 422

Spitaler, attendants on Brooks's comet, 366

Spitta, transits of Jupiter's satellites, 292

Spörer, solar rotation, 148 149; chromosphere, 199 200

Stannyan, early notice of chromosphere, 68

Star catalogues, 28, 31, 32, 60, 414 415; spectroscopic, 381 385 386 photographic, 412-414 photometric, 420 421

Star-drift, 426

Star-gauging, 13, 19, 47

Star-maps, 77, 78, 81, 284 413 415; photographic, 413 414

Stars, movements, 9, 10, 35, 39, 415 426; radial, 386 387 406 comparative brightness, 13, 49, 50, 420 421 distances, 35-37, 416-418 chemistry, 372 381 382 spectroscopic orders, 373 colours, 374 development, 375-377 actual magnitudes, 422 gregarious, 426

Stars, double, physical connection surmised, 17; proved, 18, 442 masses, 38, 42 catalogues, 43, 45, 47, 50, 418 419 orbits, 46, 418 discoveries, 43, 46, 47, 418 419 435 photographs, 409 evolution, 420

Stars, gaseous, 377-380

Stars, temporary, 24, 392-401

Stars, variable, early discoveries, 9; η Carinæ, 48, 49, 379 sun-spot analogy, 128 392 spectra, 379 Algol class, 390 391 catalogues, 391 392

Stefan, law of cooling, 219

Steinheil, stellar photometry, 420; silvered glass reflectors, 429

Stewart, Balfour, Kirchhoff's principle, 135 note; solar investigations, 154 155

Stewart, Matthew, solar distance by lunar theory, 230

Stokes, prevision of spectrum analysis, 138

Stone, E. J., reversal of Fraunhofer spectrum, 172; distance of the sun, 231 232 236 transit of Venus, 240 Cape catalogue, 415 proper motions, 426

Stone, O., star catalogues, 415; measures of double stars, 419

Stoney, carbon in photosphere, 152; dynamical theory of planetary atmospheres, 288 perturbations of Leonids, 338 status of red stars, 375

Stratonoff, star counts in Pleiades, 411

Stroobant, satellite of Venus, 256

Struve, F. G. W., stellar parallax, 35; career and investigations, 43-45 occultation by Halley's comet, 106 Russo-Scandinavian arc, 261 262

Struve, Ludwig, solar translation, 40

Struve, Otto, parallax of η Cassiopeiæ, 38; solar velocity, 40 his father's successor at Pulkowa, 45 eclipse of 1842 62, 64 Neptune's satellite, 84 research on Saturn's rings, 300 301 variable nebula, 403

Stumpe, solar translation, 40

Sun, Herschel's theory, 54-57, 70, 149; atmospheric circulation, 58, 59 chemical composition, 135 211-213 mode of rotation, 146 147 Kirchhoff's theory, 149 Faye's, 150-152 convection currents in, 150 152 165 dissociation, 152 206-210 luminous outbursts, 159-161 explosions, 205 heat emission, 216 217 221 222 225 226 temperature, 217-220 226 problem of distance, 227 results from transits, 230 232 236 240 from oppositions of Mars, 231 237 from light-velocity, 232 241 from measurements of minor planets, 238 concluded value, 242 maintenance of heat supply, 310-313 past and future duration, 312

Sun-spots, speculations regarding, 52, 53; Wilson's demonstration, 53, 154 distribution, 53, 58, 148 cyclonic aspect, 58, 144 157 158 periodicity, 126 128 162 163 magnetic relations, 127 160 161 meteorological, 129 164 auroral, 129 130 160 162 photographs, 145 154 level, 155 spectra, 156 207 208 volcanic hypothesis, 158 Lockyer's rationale, 159 planetary influence, 163 relation to Jovian markings, 297 relation to Jovian markings, 297 Swan, chromosphere, 70; sodium line, 132

Swift, E., discovery of a comet, 368

Swift, L., fallacious glimpse of Vulcan, 181 250; discovery of a comet, 368

Tacchini, eclipse of 1883 181; white prominences, 184 prominences and chromosphere, 199 200 spectrum of Venus, 254

Talbot, Fox, spectrum analysis, 131; spectroscopic method of determining stellar orbits, 387

Tarde, nature of sun-spots, 52

Taylor, eclipse expedition, 187; spectrum of Uranus, 305 achromatic lenses, 431

Tebbutt, comets discovered by, 326 352; comet of 1882 359

Telescopes, achromatic, 112 431 432

Telescopes, equatoreal, 84, 120 121

Telescopes, reflecting, Short's, 4,109 115 121; Herschel's, 12, 109-111 Lassell's, 83, 114 121 varieties of construction, 109 110 Rosse's, 115-119 434 Common's, 407 412 429

Telescopes, refracting, Fraunhofer's, 34, 35, 121; Clark's, 114 429 430 433 436 Grubb's, 430 433 with bent and horizontal mountings, 436-438

Tempel, red spot on Jupiter, 294; comet discoveries, 327 cometary observations, 352 362 Andromeda nebula, 394 discovery of Merope nebula, 410

Temperature, of the sun, 217-220 226; of the moon, 269 270 of space, 270 on Mars, 277

Tennant, eclipse observations, 168 169 174

Terby, surface of Mars, 278 279 281; secondary tail of comet, 355

Thalén, basic lines, 207; map of solar spectrum, 210 solar elements, 212

Thollon, line-displacements by motion, 202 364; atlas of solar spectrum, 211 440 lunar atmospheric absorption, 264

Thome, comet discovered by, 361

Thomson, Sir William (Lord Kelvin), solar chemistry, 138; magnetic influence of the sun, 161 tidal strains, 257 rotation of the earth, 273 dynamical theory of solar heat, 311 312

Thraen, period of Wells's comet, 357

Tidal friction, effects on moon's rotation, 271 272 318; month lengthened by, 316 318 influence on planets, 319-322 on development of binary systems, 420

Tietjen, asteroidal orbits, 284

Tisserand, capture of comets, 98; lunar acceleration, 273 revolutions of Neptune's satellite, 305 stationary radiants, 341 perturbations of Algol, 391 director of Paris Observatory, 414

Titius, law of planetary intervals, 71, 72, 85

Todd, eclipse of 1887 185; solar distance, 236 241 trans-Neptunian planet, 306

Tornaghi, halo round Venus, 254

Transit instrument, 120

Trépied, reversal of Fraunhofer spectrum, 172

Troughton, method of graduation, 122

Trouvelot, veiled spots, 148; chromosphere in 1878 175 intra-Mercurian planets, 181 250 observations of prominences, 184 196 204 of Mercury, 245 247 rotation of Venus, 252 red spot on Jupiter, 296

Trowbridge and Hutchins, carbon in sun, 212

Tschermak, origin of meteorites, 339

Tupman, transit expedition, 235; results, 236

Turner, polariscopic coronal photography, 189; employment of cœlostat, 190 438 stationary radiants, 341

Ulloa, eclipse of 1778 69

United States, observatories founded in, 6,7

Uranus, discovery, 5, 74, 111; unexplained disturbances, 78, 79, 307 satellites, 87, 303 equatoreal markings, 303 304 spectrum, 304 305 retrograde rotation, 313 315 322

Valerius, darkening of sun's limb, 221

Vassenius, description of prominences, 68

Venus, transits, 4,229 232; of 1874 233-236 of 1882 239 240 atmosphere, 236 253 254 mountains, 252 253 spectrum, 254 albedo, 255 ashen light, 255 256 pseudo-satellite, 256 effects upon, of solar tidal friction, 320

Very, temperature of sun, 220; lunar heat, 270

Vesta, discovery, 75, 76; diameter, 287 spectrum, 288

Vicaire, solar temperature, 218

Vico, comet discovered by, 97; rotation rotation of Venus, 251 Cytherean mountain, 253

Violle, solar temperature, 218 219; solar constant, 225 Vogel, H. C., solar rotation, 202; solar atmospheric absorption, 222 224 spectrum of Mercury, 245 of Venus, 255 of Vesta, 288 of Jupiter, 290 of Jupiter's satellites, 293 of Uranus, 304 rotation of Venus, 252 ashen light, 256 intrinsic light of Jupiter, 291 cometary spectra, 342 343 355 357 carbon in stars, 374; stellar development, 375 376 spectrum of Γ Cassiopeiæ, 378 of Nova Cygni, 393 of Nova Andromedæ, 395 spectroscopic star catalogue, 381 radial motion of Sirius, 386 period of Mizar, 388 eclipses of Algol, 390 components of Nova Aurigæ, 397 spectrographic determinations of radial motion, 405 406

Vogel, H. W., spectrum of hydrogen, 206 note, 383

Vulcan, existence predicted, 248; pseudo-discoveries, 249 250

Wadsworth, coronal photography, 189

Ward, Nova Andromedæ, 394

Waterston, solar temperature, 218; meteoric infalls, 311

Watson, fallacious observations of Vulcan, 181 250; asteroidal discoveries, 284

Webb, comet of 1861 326

Weber, Baily's Beads, 62; illusory transit of Vulcan, 249

Weinek, study of lunar photographs, 268

Weiss, comets and meteors, 332 334

Wells, comet discovered by, 356

Wesley, drawings of corona, 175

Wheatstone, spectrum of electric arc, 132; method of ascertaining light-velocity, 232

Whewell, stars and nebulæ, 422

Williams, A. Stanley, canals of Mars, 279; markings on Jupiter, 295 297; rotation, 296 Nova Persei, 400

Wilsing, solar rotation from faculæ, 155; density of the earth, 261 system of, 61 Cygni, 419

Wilson, Alexander, perspective effects in sun-spots, 53, 154

Wilson, H. C., red spot on Jupiter, 295; compression of Uranus, 304 exterior nebulosities of Pleiades, 411

Wilson, W. E., solar temperature, 220 222; ultra-Neptunian planets, 306

Winnecke, comet discovered by, 94; distance of the sun, 231 Donati's comet, 324 347

Wisniewski, last glimpse of 1811 comet, 99

Witt, discovery of Eros, 284

Wolf, C., objections to Faye's cosmogony, 315; origin of Phobos, 321

Wolf, Max, photographic discoveries of minor planets, 283 284; Nova Andromedæ, 394 Nova Aurigæ, 396 nebula near Nova Persei, 401 photographic nebular survey, 412 galactic nebulosity, 425

Wolf, R., sun-spot and magnetic periodicity, 128 162 163; analogy of variable stars, 128 392 auroræ, 129 suspicious transits, 249

Wollaston, ratio of moonlight to sunlight, 49; flame spectra, 131 lines in solar spectrum, 133

Woods, coronal photography, 179 180; Cape Durchmusterung, 412

Wrangel, auroræ and meteors, 335

Wright, G. F., Ice Age in North America, 260

Wright, Thomas, theory of Milky Way, 14; structure of Saturn's rings, 299

Wright, W. H., polarisation of cometary light, 355; spectrum of nebulæ, 400

Yerkes, donation of a telescope, 433

Young, Miss Anne, nebular hypothesis, 314

Young, C. A., spectrum of sun-spots, 156; origin, 158 spectrum of corona, 170 177 detection of reversing layer, 171 172 prominences and chromosphere, 194-196 200 photograph of a prominence, 197 spectroscopic measurement of sun's rotation, 202 solar cyclones and explosions, 204 205 basic lines, 207 spectrum of Venus, 254 red spot on Jupiter, 294 observations of Uranus, 303 304 Andromedes of 1892 337 spectrum of Tebbutt's comet, 355 of Nova Andromedæ, 395

Young, Thomas, absorption spectra, 136

Zach, Baron von, promotion of astronomy, 5, 6, 28; Baily's Beads, 62 search for missing planet, 72 rediscovery of Ceres, 74 use of a heliostat, 120

Zantedeschi, lines in solar spectrum, 134; lunar radiation, 269 lunar radiation, 269

Zenger, observations on Venus, 253 255

Zenker, cometary tails, 348

Zezioli, observation of Andromedes, 334

Zodiacal light, relation to medium of space, 94; to solar corona, 176; meteoric constitution, 310

Zöllner, electrical theory of comets, 99, 344 346 347; solar constitution, 158 observations of prominences, 194 196 reversion spectroscope, 202 solar temperature, 220 Mercurian phases, 245 albedo of Venus, 255 of Jupiter, 290 of Saturn, 303 of Uranus, 304 condition of Venus, 256 of great planets, 289 Jovian markings, 297 ages of stars, 375 polarising photometer, 420 421

THE END

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