part ii.

Chapter 4212,942 wordsPublic domain

1899 Innes's _Reference Catalogue of Southern Double Stars_. 1899 Keeler's photographs of nebulae with the Crossley reflector and generalization of their spiral character. 1899, January Spectrum of Andromeda nebula photographed by Scheiner. 1899, April Photographic discovery of Nova Aquilae by Mrs. Fleming. 1899, Aug. 26 Installation of 31-inch photographic refractor at Potsdam. 1899 Campbell's detection of Polaris as spectroscopically triple. 1899, October Duplicate discovery by Campbell and Newall of Capella as a spectroscopic binary. 1899, Nov. 15 Failure of the Leonids. Deflection of the stream predicted by Johnstone Stoney and Downing. 1899, December Publication of Sir William and Lady Huggins's _Atlas of Representative Stellar Spectra_. 1899 Thirty-two-inch photographic refractor mounted at Meudon. 1899 Issue of first volume of Potsdam measures of international catalogue plates. 1900, Jan. 27 Kapteyn's determination of the apex of solar motion. 1900 Chase's measures for parallax of swiftly-moving stars. 1900 Publication of Gill's _Researches on Stellar Parallax_. 1900 Kapteyn proposes a method for a stellar parallax Durchmusterung, and gives specimen results for 248 stars. 1900 Burnham's general catalogue of 1,290 double stars. 1900 Publication of the concluding volume of the _Cape Photographic Durchmusterung_. 1900, May 28 Spanish-American total eclipse of the sun. 1900, July International Conference at Paris. Co-operation arranged of fifty-eight observatories in measures of Eros for solar parallax. 1900 Horizontal refractor, of 50 inches aperture, 197 feet focus, installed in Paris Exhibition. 1900, Aug. 12 Death of Professor Keeler. Succeeded by Campbell in direction of Lick Observatory. 1900, November Opposition of Eros. 1900 Publication of Roberts's _Celestial Photographs_, vol. ii. 1900 Complete publication of Langley's researches on the infra-red spectrum. 1900 Printing begun of Paris section of International Photographic Catalogue. 1901, Feb. 22 Nova Persei discovered by Anderson. 1901, February Variability of Eros announced by Oppolzer. 1901, April 23 Apparition of a great comet at the Cape. 1901 Publication of Pickering's _Photometric Durchmusterung_. 1901 Miss Cannon's discussion of the spectra of 1,122 Southern stars. 1901 Kapteyn's investigation of mean stellar parallax. 1901 Campbell's determination of the sun's velocity. 1901 Porter's research on the solar motion in space. 1901 Bigelow's magnetic theory of the solar corona. 1901 Hussey's measurements of the Pulkowa double stars. 1901 Radial velocities of the components of Delta Equulei measured at Lick. 1901, April 16 Death of Henry A. Rowland. 1901, June Nebular spectrum derived from Nova Persei. 1901, Aug. 23 Nebula near Nova Persei photographed by Max Wolf. 1901, Sept. 20 The same exhibited in spiral form on a plate taken by Ritchey at the Yerkes Observatory. 1901, Nov. 8 Photograph taken by Perrine with the Crossley reflector showed nebula in course of rapid change. 1901, Sept. 19 Unveiling of the McClean "Victoria" telescope at the Royal Observatory, Cape of Good Hope. 1901 Sun-spot minimum.

TABLE II.

CHEMICAL ELEMENTS IN THE SUN (ROWLAND, 1891).

Arranged according to the number of their representative Lines in the Solar Spectrum.

Iron (2000+). Neodymium. Cadmium. Nickel. Lanthanum. Rhodium. Titanium. Yttrium. Erbium. Manganese. Niobium. Zinc. Chromium. Molybdenum. Copper (2). Cobalt. Palladium. Silver (2). Carbon (200+). Magnesium (20+). Glucinum (2). Vanadium. Sodium (11). Germanium. Zirconium. Silicon. Tin. Cerium. Strontium. Lead (1). Calcium (75+). Barium. Potassium (1). Scandium. Aluminium (4).

_Doubtful Elements._--Iridium, osmium, platinum, ruthenium, tantalum, thorium, tungsten, uranium.

_Not in Solar Spectrum._--Antimony, arsenic, bismuth, boron, nitrogen (vacuum tube), caesium, gold, iridium, mercury, phosphorus, rubidium, selenium, sulphur, thallium, praseodymium.

Oxygen was added to the solar ingredients by Runge and Paschen in 1896, gallium by Hartley and Ramage in 1899. Lithium may be admitted provisionally, and the chromospheric constituent helium takes rank, since 1895, as a chemical element.

TABLE III.

EPOCHS OF SUN-SPOT MAXIMUM AND MINIMUM FROM 1610 TO 1901.

+----------+----------++----------+----------+----------+----------+ | Minima. | Maxima. || Minima. | Maxima. | Minima. | Maxima. | +----------+----------++----------+----------+----------+----------+ | 1610.8 | 1615.5 || 1712.0 | 1718.2 | 1810.6 | 1816.4 | | 1619.0 | 1626.0 || 1723.5 | 1727.5 | 1823.3 | 1829.9 | | 1634.0 | 1639.5 || 1734.0 | 1738.7 | 1833.9 | 1837.2 | | 1645.0 | 1649.0 || 1745.0 | 1750.3 | 1843.5 | 1848.1 | | 1655.0 | 1660.0 || 1755.2 | 1761.5 | 1856.0 | 1860.1 | | 1666.0 | 1675.0 || 1766.5 | 1769.7 | 1867.2 | 1870.6 | | 1679.5 | 1685.0 || 1775.5 | 1778.4 | 1878.9 | 1884.0 | | 1689.5 | 1693.0 || 1784.7 | 1788.1 | 1890.2 | 1894.0 | | 1698.9 | 1705.5 || 1798.3 | 1804.2 | 1901.9 | | +----------+----------++----------+----------+----------+----------+

TABLE IV.

MOVEMENTS OF SUN AND STARS.

1. Translation of Solar System.

2. Stellar Velocities.

TABLE V.

LIST OF GREAT TELESCOPES.

TABLE VI.

List of Observatories employed in the Construction of the Photographic Chart and Catalogue of the Heavens.

All are provided with 13-inch photographic, coupled with 11-inch visual refractors:

---------------------------------------------------------- | Name of Observatory. | Constructors of Instruments.| | |-------------------------------| | | Optical Part.|Mechanical Part.| |------------------------|--------------|----------------| |Paris | Henrys | Gautier | |Algiers | " | " | |Bordeaux | " | " | |Toulouse | " | " | |San Fernando (Spain) | " | " | |Vatican | " | " | |Cordoba | " | " | |Montevideo | " | " | |Perth, Western Australia| " | " | |Helsingfors | " | Repsold | |Potsdam | Steinheil | " | |Catania | " | Salmoiraghi | |Greenwich | Sir H. Grubb | Sir H. Grubb | |Oxford | " | " | |The Cape | " | " | |Melbourne | " | " | |Sydney | " | " | |Tacubaya (Mexico) | " | " | ----------------------------------------------------------

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 nebulae, 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 Aurigae, 396; of Nova Persei, 400

Andrews, conditions of liquefaction, 151

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

Angstrom, 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 aurorae, 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

Aurorae, 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 Aurigae, 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 Maedler, surveys of lunar surface, 265, 267; studies of Mars, 275

Belopolsky, coronal photographs, 185; theory of corona, 191; rotation of Venus, 252; of Jupiter, 297; spectroscopic determinations of Saturn's rings, 300; spectrum of Gamma Cassiopeiae, 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 Coronae, 393

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

Bischoffsheim, Coude 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 nebulae, 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 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

Bredikhine, 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, _Theorie 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

Bruennow, 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 Eta Carinae, 48

Burnham, stellar orbits, 46; coronal photographs, 186; measures of Nova Aurigae, 399; of planetary nebulae, 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 Aurigae, 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

Carinae, Eta, 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 Gamma Cassiopeiae, 378; of Nova Andromedae, 395; of Orion nebula, 407; discoveries of gaseous stars, 379; Nova Aurigae, 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, 178-180; 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 nebulae, 403; measures of nebulae, 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

Daubree, 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; Coude 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 Nebulae, 50

Dulong and Petit, law of radiation, 217, 219

Duner, 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 Aurigae, 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

Faculae, 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

Fenyi, 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 Beta Lyrae, 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; Coude 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, nebulae 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 Aurigae, 398; photographs of nebulae, 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 Andromedae, 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 faculae, 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 nebulae, 22; observation of Eta Carinae, 48; eclipse of 1715, 66, 68; predicted return of comet, 88; magnetic theory of aurorae, 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 Andromedae, 394

Hasselberg, metallic spectra, 211; spectra of comets, 342, 357; of Nova Andromedae, 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 Alpha Centauri, 36, 416; observation of chromosphere, 68

Henry, Paul and Prosper, lunar twilight, 264; markings on Uranus, 303; photograph of Saturn, 408; photographs of nebulae 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 nebulae, 404; double nebulae, 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 nebulae, 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 Aurigae, 398; Orion and Trifid nebulae, 403, 404; director of Lick Observatory, 435

Holden and Schaeberle, observations of nebulae, 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 Aurigae, 397; spectra of nebulae, 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 Aurigae, 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 Delta 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 nebulae, 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 nebulae, 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 nebulae, 402; photographs of nebulae, 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 Gamma Cassiopeiae, 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

Krueger, segmentation of great comet, 362

Kuestner, variation of latitude, 258

Kunowsky, spots on Mars, 275

Lacaille, southern nebulae, 22; Eta Carinae, 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 Celeste_, 31, 415; nature of sun-spots, 53; observations of Neptune, 83

Lambert, solar motion, 10; 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; _Systeme 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

Ligondes, 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 Coude, 438

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

Lohrmann, lunar chart, 265; Linne, 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 Eta Carinae, 49; observation of Halley's comet, 102

Maedler, central sun, 41; observations of Venus, 253; lunar rills, 263; aspect of Linne, 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 nebulae, 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 nebulae, 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 nebulae, 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

Moeller, 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

Mueller, 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

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

Nebulae, 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 Andromedae, 394, 395

Nova Aurigae, 396-399

Nova Cygni, 393, 394, 398

Nova Persei, 400, 401

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

Nyren, constant of aberration, 241

Observatory, Greenwich, 3, 27, 433; Cape of Good Hope, 6, 36, 433; Paramatta, 6, 90; Harvard College, 7, 85; Koenigsberg, 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; nebulae, 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 Schroeter, 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

Pingre, 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; nebulae, 410, 411

Pluecker, 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

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

Pons, discoveries of comets, 90, 94, 365

Pontecoulant, 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 Beta Aurigae, 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 Andromedae, 403; status of nebulae, 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 nebulae, 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 Gamma Argus, 380

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

Riccioli, secondary light of Venus, 255

Ricco, 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 nebulae, 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

Roemer, 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 nebulae, 118; resolution of nebulae, 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

Ruemker, observation of Encke's comet, 90

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

Savelieff, 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 nebulae 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 Linne, 267; cometary appendages, 363; new stars, 393

Schoenfeld, extension of Bonn Durchmusterung, 412, 414

Schrader, construction of reflectors, 243

Schroeter, 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; Linne, 267; spots on Mars, 275; Jovian markings, 290

Schuelen, 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 Andromedae, 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 faculae, 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 nebulae, 401-403

Spencer, position of nebulae, 422

Spitaler, attendants on Brooks's comet, 366

Spitta, transits of Jupiter's satellites, 292

Sporer, 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; Eta Carinae, 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 Eta Cassiopeiae, 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

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

Thalen, 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

Trepied, 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 coelostat, 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 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 Gamma Cassiopeiae, 378; of Nova Cygni, 393; of Nova Andromedae, 395; spectroscopic star catalogue, 381; radial motion of Sirius, 386; period of Mizar, 388; eclipses of Algol, 390; components of Nova Aurigae, 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 Andromedae, 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 nebulae, 422

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

Wilsing, solar rotation from faculae, 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 Andromedae, 394; Nova Aurigae, 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; aurorae, 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, aurorae 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 nebulae, 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 Andromedae, 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

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

Zoellner, 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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Transcriber's notes:

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