INDEX.

A Aberration of light, 503–512; and the apparent movements of stars, 504, 507; Bradley's discoveries, 503; causes, 507–511; circles of stars, 505–507; dependent upon the velocity of light, 511; effect on Draco, 505; telescopic investigation, 510 Achromatic combination of glasses, 11 Adams, Professor J.C., and the discovery of Neptune, 324–327, 330–332; and the Ellipse of the Leonids, 386 Aërolite, the Chaco, 398; the Orgueil, 399 Airy, Sir George, 325 Alban Mount Meteorites, the, 393 Alcor, 438 Aldebaran, 209, 418, 419; spectrum of, 480; value of velocity of, 484 Algol, 485, 487 Almagest, the, 7 Alphonsus, 92 Alps, the great valley of the (lunar), 88 Altair, 424 Aluminium in the Sun, 50 Ancients, astronomy of the, 2–7 Andrews, Professor, and basaltic formation at Giant's Causeway, 407 Andromeda, 414; nebula in, 469, 489 Andromedes, The, shooting star shower, and Biela's comet, 390 Antares, 423 Apennines (lunar), 83 Aphelion, 163 Aquarius, 215, 413 Aquila, or the Eagle, 424 Arago, 326 Archimedes, 88 Arcturus, 358, 480; value of velocity of, 484 Argelander's Catalogue of Stars, 431, 476 Argus, 481 Ariel, 309, 559 Aristarchus, 90 Aristillus, 88 Aristotle, lunar crater named after him, 88; credulity respecting his writings, 267; the Moon and the tides and, 535 Asteroids, 229–244 Astrea, 328 Astronomers of Nineveh, 156 Astronomical quantities, 558 Astronomy, ancient, 2–7; Galileo's achievements in, 10; the first phenomenon of, 2 Athenæum, the, and Sir John Herschel's letter on Adams's share in the discovery of Neptune, 330 Atmosphere, height of the Earth's, 100 Attraction, between the Moon and the Earth, 75; between the planets, 148; between the Sun and the planets, 144, 148; of Jupiter, 248, 249; producing precession, 498 Auriga, 414, 489 Aurora borealis, 42 Autolycus, 88 Auwers and star distances, 449; and the irregularity in movement of Sirius, 427 Axis, Polar, 196, 497; precession and nutation of the Earth's, 492–502 B Backlund, and Encke's comet, 349, 351 Barnard, Professor E.E., and Saturn, 271, 278, 282; and Titan, 294; and the comet of 1892, 355; and the Milky Way, 475 Beehive, the, 422 Belopolsky, M., and Binaries, 487, 488 Benares meteorite, the, 392 Bessel, and Bradley, 501; and the distance of 61 Cygni, 446, 448, 449; and the distances of stars, 442; and the irregular movements of Sirius, 426; receives gold medal of Royal Astronomical Society, 442 Betelgeuze, 209, 418, 419, 482; value of velocity of, 484 Biela's comet, and Sir John Herschel, 357; and the Andromedes, 390 Binaries, spectroscopic, 487 Binocular glass, 27 Biot and the L'Aigle meteorites, 392 Bode's law, 230; list of double stars, 435 Bond, Professor, and Saturn's satellites, 296; and the nebula in Orion, 469; and the third ring of Saturn, 280 Boötes, 422 Bradley, and nutation, 501; and the aberration of light, 503; his observations of Uranus, 312 Bredichin, Professor, and the tails of comets, 365, 366, 367 Breitenbach iron, the, 397 Bristol Channel, tides in the, 538 Brünnow, Dr., observations on the parallax of 61 Cygni, 449 Burial of Sir John Moore, 72 Burnham, Mr., and the orbit of Sirius, 427; his additions to the known number of double stars, 439 Butler, Bishop, and probability, 460 Butsura meteorite, 397 C Cadmium in the Sun, 50 Calais, tides at, 536 Calcium in the Sun, 50 Campbell, Mr., and Argus, 481; and Mars, 223 Canals on Mars, 220 Cancri 20, 154 Cancri, ζ, 154 Cancri, θ, 154 Canis major, 419 Canopus, 422 Cape Observatory, 27 Capella, 414, 480, 487 Carboniferous period, 518 Cardiff, tides at, 538 Cassini, J.D., and double stars, 434; and Saturn's satellites, 294; and the rings of Saturn, 278 Cassiopeia, 412 Castor, 420, 487; a binary star, 437; revolution of, 437 Catalogues of stars, 310, 311; Messier's, 529 Catharina, 92 Centauri, α, 422; Dr. Gill's observations of, 451; Henderson's measurement of distance of, 442, 451 Ceres, 231, 232, 238; and meteorites, 404, 405 Chaco meteorite, the, 398 Chacornac, and the lunar crater Schickard, 90 Challenger, the cruise of the, and magnetic particles in the Atlantic, 408 Challis, Professor, 326; his search for Neptune, 327, 328, 331, 332 Chandler, Mr., and Algol, 485 Charles's Wain, 28 Chepstow, tides at, 538 Chéseaux, discoverer of comet of 1744, 367 Chicago, telescope at Yerkes Observatory, 16 Chladni and the meteorite of Siberia, 392 Chromium in the Sun, 50 Chromosphere, the, 54 Chronometers tested by the Moon, 80 Clairaut and the attraction of planets on comets, 342, 343 Clavius, 91; and Jupiter's satellites, 267 Clock, astronomical, 23 Clusters, star, 461–464 Cobalt in the Sun, 50 Coggia's comet, 1874, 337 Colour of light and indication of its source, 46 Colours, the seven primary, 45 Columbiad, the, 401 Columbus, 7 Comets, 112, 149, 250, 336; and the spectroscope, 355; attraction from planets, 342, 360; Biela's, 357; Biela's and the Andromedes, 390; Clairaut's investigations, 342, 343; Coggia's, 337; Common's (1882), 354; connection of, with shooting star showers, 388; constitution of, 336; containing sodium and iron, 356; Donati's (1858), 353, 358, 366; eccentricity of, 360; Encke's, 344–352; existence of carbon in, 356, 367; gravitation and, 343, 348; Halley's investigations about, 341–344; head or nucleus of, 337; Lexell's, 370; mass of, 359; movements of, 336; Newton's explanations of, 338; non-periodic, 353–356; of 1531, 341; of 1607, 341; of 1681, 338, 339; of 1682, 341; of 1744 (Chéseaux's), 367; of 1818, 345; of 1843, 352; of 1866, 388; of 1874, 337; of 1892, 355; origin of, 369; parabolic orbits of, 338–340, 360; periodic return of, 338–341; shape of, 336; size of, 337; tailless, 370; tails of, 337, 361; Bredichin's researches, 365; Chéseaux's, 367; composition of, 365, 369; condensation of, 369; electricity and, 368; gradual growth of, 363; law of direction of, 362; repelled by the Sun, 364; repulsive force of, 364, 368; various types of, 365; Tebbutt's (1881), 353; tenuity of, 357 Common, Dr., constructor of reflectors, 21; and the comet of 1882, 354; and the nebula in Orion, 469 Cook, Captain, and the transit of Venus, 184 Copeland, Dr., and Schmidt's star, 489; and the lunar crater, Tycho, 92; and the spectra of nebula, 473; and the transit of Venus, 189 Copernicus and Mercury, 156; confirmation of his theory by the discovery of Jupiter's satellites, 267; his theory of astronomy, 7; lunar crater called after him, 89 Copper in the Sun, 50 Cor scorpionis, 423 Corona Borealis, 423, 488 Corona of Sun, during an eclipse, 62–64, 151 Coronium, 64 Cotopaxi and meteorites, 401 Crab, the, 422 Crabtree, and the transit of Venus, 180 Crape ring of Saturn, 281 Craters in the Moon, 83–85, 87–98 Critical velocity, 103, 104, 237 Crown, the, 423 Cryptograph of Huyghens, the, 277 Cygni, β, 439 Cygni 61, annual parallax of, 450; Bessel's measurement of distance of, 442, 446, 447; Brünnow's observations of, 449; distance from the Sun of, 452; disturbing influence of, 452; double, 446; Professor A. Hall's measurement of, 449; Professor Pritchard's photographic researches concerning, 449; proper motion of, 446; Struve's observations of, 448, 449; velocity of, 452 Cygnus, 424 Cyrillus, 92 Cysat, and the Belt of Orion, 467 D D line in solar spectrum, 48 Darwin, Professor G.H., and tidal evolution, 531 Dawes, Professor, and Saturn's third ring, 281 Day, length of, and the Moon, 542; and the tides, 541 Deimos, 226, 558 Denebola, 423 Diffraction, 56 Dione, 559 Dispersion of colours, 47 Distances, astronomical, 558, 559 Doerfel, and comets, 339 Dog star (see Sirius) Dog, the Little, 420 Donati's comet, 353, 358; tails, 366 Double stars, 434–440 D Q, 236 Draco, nebula in, 470 Dragon, the, 415 Draper, Professor, and the nebula in Orion, 469 Dunsink Observatory, 12, 184, 447, 449 Dynamical stability, 547; theory of Newton, 214 Dynamics and the Earth-Moon system, 546 Dynamics, Galileo the founder of, 10 E Eagle, the, 424 Earth, The, ancient ideas respecting, 3; annual movement of, and the apparent movement of the stars, 507, 512; attraction of Jupiter, 319; attraction of on Encke's comet, 350; attraction of, on the Leonids, 386; attraction of Saturn, 319; attraction of the Moon, 75, 497; attraction of the Sun, 496; axial rotation of, 558; carboniferous period on, 518; change of climate on, 518; composition of, 496; contact of atmosphere of, with meteors, 377–379; density of, 558; diameter of, 558; distance of, from Mars, 213; distance of, from the Moon, 73, 558; distance of, from the Sun, 31, 114, 184, 240, 265, 351, 512, 558; energy from rotation of, 540; formerly a molten globe, 200, 201; geological records and, 517; glacial period on, 518; gravitation and, 204, 206, 207, 497; heat in the interior of, 94, 197, 198, 251, 514; how it is measured, 193–196; its mass increasing owing to the fall of meteoric matter, 408; its oceans once vapour, 251; once in immediate proximity to the Moon, 542; orbit of, 114; orbit of, its elliptic form, 139; path of deranged by Venus and Mars, 319; periodic time of, 558; plane of orbit of, 309; polar axis of, 196, 492–502; position of, relatively to the Sun and the Moon, 76, 77; precession and nutation of axis of, 492–502; radius of, 193, 512; rotation of, 75, 196, 200, 494, 496; shape of, 192, 195, 197, 201, 207; size of, compared with Jupiter, 119, and with other planets, 119; size and weight of, compared with those of the Sun, 30, and Moon, 74, 75; velocity of, 115, 139, 146, 512, and periodic time, 143; volcanic outbreaks on, 197, and the origin of meteorites, 405; weight of, 202, 248, as compared with Saturn, 271, 272 Earthquakes, astronomical instruments disturbed by, 24 Eccentricity of planetary ellipses, 136, 211 Eclipse of Jupiter's satellites, 261, 262, 265–267 Ellipse of the Moon, 77–80; of the Sun, 53 Eclipses, ancient explanations of, 6; calculations of the recurrence of, 79, 80 Ecliptic, the, 5, 233; Pole of the, 493, 500, 505 Electric Light, the, 44 Ellipse, the, 136; eccentricity of, 137; focus of, 137; Kepler's discoveries respecting, 136, 138, 142–144, 505; the form which the orbit of a planet takes, 136; the parallactic, 444; variety of form of, 139 Enceladus, 559 Encke, and the distance of the Sun from the Earth, 147, 184; his comet, 344–352 Encke's comet, 344–352; approach to Jupiter of, 349; and Mercury, 349; and the Sun, 346; diminution in periodic time of, 351; distance from Mercury of, 347; disturbed by the Earth, 350, and by Mercury, 348; irregularities of, 347, 351; orbit of, 346; periodical return of, 351; Von Asten's calculations concerning, 349–350 Energy supplying the tides, 539 Ensisheim meteorite, the, 393 Equatorial diameter, 196, 497; telescope, 14 Eratosthenes, 89 Eros, 236 Eruptions, 197 Evening star, 109, 169 Eye, structure of the, 10 F Faculæ of the Sun, 37 Fire ball of 1869, 375 Fire balls, 374 "Fixed" stars, 503 Flamsteed, first Astronomer-Royal, 311; his Historia Cœlestis, 311 Focus of planetary ellipse, 137–139 Fomalhaut, 413 Fraunhofer, 478 Fraunhofer lines, 48 Fundy, Bay of, tides in, 538 G Galileo, achievements of, 10; and Jupiter's satellites, 267; and Saturn's rings, 273, 274; and the Pleiades, 418 Galle, Dr., and Neptune, 328–330 Gassendi, and the transit of Mercury, 164; and the transit of Venus, 178; lunar crater named after him, 90 Gauss, and the minor planet Ceres, 232 Gemini, constellation of, 303, 420 Geminids, the, 400 Geologists and the lapse of time, 453 Geometers, Oriental, 5 Geometry, cultivation by the ancients of, 6 George III. and Sir W. Herschel, 299, 306 Giant's Causeway, 407 Gill, Dr. D., 27; and Juno, 243; and the minor planets, 242; and the parallax of α Centauri, 451; and the parallax of Mars, 214 Glacial period, 518 Gravitation, law of, 122–149; and binary stars, 437; and precession, 497; and the Earth's axis, 495, 497, 499; and the parabolic path of comets, 340; and the periodical return of comets, 343; and the weight of the Earth, 203, 204; illustrated by experiments, 123, 124, 127, 129–132; its discovery aided by lunar observations, 108, 125; its influence on the satellites, 149; its influence on stars, 149; its influence on tides, 149; Le Verrier's triumphant proof of, 330; Newton's discoveries, 125, 126, 147; on the Moon, 96; universality amongst the heavenly bodies, 128, 373 Great Bear, 27, 28, 241; configuration, 410; double star in the, 438; positions of, 409, 411 Green, Mr., and Mars, 220 Greenwich Observatory, 26, 311 Griffiths, Mr., and Jupiter, 252 Grimaldi, 90 Grubb, Sir Howard, 14 "Guards," the, 412 Gulliver's Travels and the satellites of Mars, 228 H Hadley's observations of Saturn, 282 Hall, Professor Asaph, and the satellites of Mars, 225 Halley, and the periodicity of comets, 341–343; and the transit of Venus, 180 Heat, bearings on astronomy, 513; in the interior of the Earth, 197–199, 514; of the Sun, 515–526 Heliometer, the, 243 Helium, 55 Henderson, and the distance of α Centauri, 442, 451 Hercules, star cluster in, 269, 462 Herodotus (lunar crater), 90 Herschel, Caroline, 299, 465 Herschel, Sir John, address to British Association, 328; address on the presentation of gold medal to Bessel, 443; and Biela's comet, 357; and nebulæ, 464; letter to Athenœum on Adams's share in the discovery of Neptune, 330 Herschel, Sir W., and double stars, 435, 436; and Saturn, 279; and Saturn's satellites, 295; and the Empress Catherine, 301; and the movement of solar system towards Lyra, 457; discovery of satellite of Uranus by, 308, 309; discovery of Uranus by, 305, 308; early life of, 299; friendship with Sir W. Watson of 302; he makes his own telescopes, 301; "King's Astronomer," 307; method of making his telescopes, 302; musical talent of, 299; organist of Octagon Chapel, Bath, 300; pardon for desertion from George III., 299; passion for astronomy of, 300, 301; relinquishes musical profession, 307; sidereal aggregation theory of, 529; study of the nebulæ by, 464–465, 529 Herschelian telescope, 19 Historia Cœlestis, 311 Hœdi, the, 414 Holmes's, Mr., comet (1892), 355 Horrocks, and the transit of Venus, 179 Howard, Mr., and the Benares meteorite, 392 Huggins, Sir W., 479, 483; and nebulæ, 472 Huyghens, and Saturn's rings, 275–278; discovers first satellite of Saturn, 293 Hyades, the, 419 Hydrogen in Sirius and Vega, 479; in the Sun, 50 Hyginus, 93 Hyperion, 559 I Iapetus, 559 Iberians, the, 3 Inquisition, the, and Galileo, 10 Iris, 242 Iron, dust in the Arctic regions, 408; in the Sun, 50; of meteorites, the, 396; spectrum of, 50 J Janssen, M., 34, 53; and the transit of Venus, 177 Juno, 233, 238 Jupiter, ancient study of, 6; and the Leonids, 386; attraction of, 248; axial rotation of, 558; belts of, 252; brilliancy of, 257; composition of, 250; covered with an atmosphere of clouds, 253, 254; density of, 558; diameter of, 247, 558; distance from the Earth of, 110, 111; distance from the Sun of, 246, 558; habitability of, 257; heat received from the Sun by, 256; internal heat of, 252, 256, 515; lack of permanent features of, 253; lack of solidity of, 248, 253, 254; moment of momentum of, 554, 555; occultation of, 255; orbit of, 114, 115, 246; path of, perturbed by the attraction of Saturn, 316; periodic time of, 558; a planet, or "wanderer," 111; red spot in 1878, 253; revolution of, 246; rotation of, 201, 202; satellites of, 247, 249, 257–261, 265, 559; satellites of, and gravitation, 266; satellites of, and the Copernican theory, 267; shadow from satellites of, 257; shape of, 201, 202, 247, 252; size of, compared with the Earth, 19, 246, 248, and other planets, 114; and the Sun, 114; storms on, 256; tides on, 555; weight of, 248, 250, and Encke's comet, 350 K Keeler, Professor, and Saturn's ring, 288 Kempf, Dr., and the Sun's velocity, 484 Kepler, and comets, 360; and laws of planetary motion, 10; and meteors, 386; and the orbit of Mars, 209; explanation of his laws, 147, 148, 533; his discovery of the shape of the planetary orbits, 136, 138; his first planetary law, 138; lunar crater called after him, 90; prediction of the transit of Venus and Mercury, 163, 178; second law, 141; third law, 142 Kids, the, 414 Kirchhoff, and spectrum analysis, 478 Kirkwood, Professor, and the movements of Saturn's satellites, 296 Klinkerfues, Professor, 390 L Lagrange, and the theory of planetary perturbation, 320–322; his assumption of planetary rigidity, 531 L'Aigle meteorites, the, 392 Lalande, and Neptune, 332, 333 Landscapes, lunar, 98 Lane, Mr. J. Homer, 522 Laplace, and the nebular theory, 526; and the satellites of Jupiter, 266; and the theory of planetary perturbation, 320 Lassell, Mr., and Saturn's eighth satellite, 296; discovers Neptune's satellite, 334 Law of gravitation (see Gravitation) Laws of Planetary Motion (see Planetary Motion) Lead in the Sun, 50 Ledger, Mr., and Mercury, 163 Leibnitz, lunar mountains named after him, 93 Lemonnier, and Uranus, 312 Leo, and shooting stars, 380, 420 Leonids, attractions of planets on, 386; breadth of stream of, 387; change of shape of, 383; decrease of, 385; enormous number of, 382; historical records, 383; length of stream of, 387; Le Verrier, and the cause of their introduction into the solar system, 388; meteor shoal of, 382; periodic return of, 382; their connection with comets and Professor, Schiaparelli, 388 Leonis γ, value of velocity of, 484 Leverage by equatorial protuberance, 498 Le Verrier, and Mars, 214; and the discovery of Neptune, 324–332; and the introduction of the Leonids into the solar system, 388; and the weight of Mercury, 349 Lexell's comet, 370 Libration, 84 Lick Observatory, 16 Light, aberration of, 503–512; velocity of, 261, 262, 265, 505, 512 Linné, 87, 94 Lion, the, 420, 421 Little Bear, the, 412 Little Dog, the, 420 Livy, and meteorites, 393 Lloyd, Provost, 407 Lockyer, Sir Norman, and Betelgeuze, 482; and solar light, 52 London, tides at, 538 Louvain, F. Terby, and Titan, 295 Lowell, Mr., and Mercury, 165 Lunar tides, 548, 549 Lyra, motion of solar system towards, 459 Lyre, the, 424; Nebula in, 469 Lyrids, the, 400 M Mädler, and the lunar craters, 88, 90, 91 Magellanic clouds, 463 Magnesium, colour of flame from, 46; in the Sun, 50 Magnetism, connection with Sun spots, 42 Manganese in the Sun, 50 Maraldi, and the rings of Saturn, 279 Mare crisium, 83; fœcunditatis, 83; humorum, 83; imbrium, 83, 98; nectaris 83; nubium, 83; serenitatis, 83; tranquillitatis, 83; vaporum, 83 Mars, ancient study of, 6; appearance of, through the telescope, 218; atmosphere of, 222; axial rotation of, 558; canals on, 220; density of, 558; diameter of, 558; distance, from the Earth of, 213; distance from the Sun of, 213, 558; gravitation on, 225; Le Verrier's discovery of, 214; life improbable on, 224; marking on, 218; movements of, 211–213; opposition of, 209–211; orbit of, 116, 209, 210, 213; orbit of, and the laws of Kepler, 209; parallax (1877), and Dr. D. Gill, 214; periodic time of, 558; a planet or "wanderer," 111; "Polar Caps" on, 218, 219; proximity to the Earth of, 110; rising and setting of, 209; rotation of, 218; satellites of, 225–228, 558; size of compared with other planets, 116, 216; tides on, 551; water and ice on, 219, 224 Maximilian, Emperor, 393 Mayer, Tobias, and Uranus, 312 Measurement of the Earth, 193–196 Mediterranean, tides in the, 537 Mercury, ancient study of, 6; antiquity of its discovery, 155–157; atmosphere of, 166; attraction on comets of, 347; climate of, 163; comparative proximity to the Earth of, 111; composition of, 160; crescent-shaped, 160; density of, 558; diameter of, 558; distance from the Sun of, 151, 558; habitability of, 163; movement of, 160, 161; its elliptic form, 139, 161; orbit of, 114; period of revolution of, 161; periodic appearances of, 158; periodic time of, 558; perturbations of, 350; a planet or "wanderer," 111; revolution of, 165; rotation of, and Professor Schiaparelli, 165; size of, compared with other planets, 116; surface of, 162; transit of, 152; transit of, and Gassendi's observations, 164; transit of, predicted by Kepler, 163; velocity of, 162; weight of, 166, 349 Meridian circle, 22, 24 Messier's Catalogue of Stars, 529 Meteors (see Stars, shooting) Meteorites, 391; Alban Mount, 393; ancient accounts, 392, 393; Benares, 392; Butsura, 397; Chaco, 398; characteristics of, 397; Chladni's account of discovery in Siberia, 392; composition of, 397–399; Ensisheim (1492), 393; Hindoo account of, 391; L'Aigle, 392; not connected with comets, 400; not connected with star showers, 400; Orgueil, 399; origin, 400–408; Ovifak, 407; Rowton, 395–396; Wold Cottage, 392 Micrometer, 86 Milky Way, 462–3, 474–6 Mimas, 559 Minor planets, 229–244 Mira Ceti, 430, 482 Mizar, 438, 486 Moment of momentum, the, 552–554 Month of one day, 547 Moon, The, absence of air on, 85, 99; absence of heat on, 95; agent in causing the tides, 70, 535–537; ancient discoveries respecting, 5; apparent size of, 73; attraction to the Earth of, 75; brightness of, as compared with that of the Sun, 71; changes during the month of, 71, 74; chart of surface of, 81; craters on, 83, 84, 87–98, 514; density of, 558; diameter of, 558; distance from the Earth of, 73, 75, 568; eclipses of, 6, 77–80; illustration of the law of gravitation, 96, 131, 133; landscapes on, 98; life impossible on, 99; measuring heights of mountains, etc., of, 85, 86; micrometer, 86; motion of, 75; mountains on, 83, 85, 88, 89, 91, 93; phases of, 71, 76; plane of orbit of, 310, 500, 501; poets and artists and, 72; pole, 500; possibility of ejecting meteorites, 402; possibly fractured off from the earth, 543; prehistoric tides on, 548, 549; produces precession, 497–499; proximity to the Earth of, 73, 75; receding from the Earth, 545; relative position of with regard to the Earth and the Sun, 76, 77; revolution of, round the Earth, 75, 76, 558; "seas" on, 82, 83; shadows of, 85; size of, compared with that of the Earth, 74; test for chronometers, a, 80; thraldom of terrestrial tides, 549; waterless, 100; weather not a affected by the phases of, 82; weight of, 74 Motion, laws of planetary, 138, 141, 142, 147, 148 Mountains of the Moon, 83, 85, 93 N Nasmyth, Mr., and the formation of lunar craters, 95 Natural History Museum, meteorites, 394 Nautical Almanack, 189 Neap Tides, 538 Nebula, in Andromeda, 469; annular, in Lyra, 469; in Orion, 269, 461, 466–469; colour of, 468; magnitude of, 468; nature of, 467; planetary, in Draco, 470; simplest type of a, 528; various grades of, 528 Nebulæ, 464–472; condensation, 528; distances of, 464; double, 470; Herschel's labours respecting, 464–465, 528, 529; number of, 466; planetary, 470; self-luminous, 464; smallest greater than the Sun, 464; spiral, 470 Nebular theory, the, 526 Neptune, 112; Adams's researches, 324–326, 332; Challis's observations of, 326–328; density of, 558; diameter of, 333, 558; disc of, 332; discovery (1846) of, 315; distance from the Sun of, 334, 558; Lalande's observations of, 332, 333; Le Verrier's calculations, 324–332; moment of momentum of, 554; orbit of, 117; periodic time of, 558; revolution of, 334; rotation of uncertain, 333; satellite of, discovered by Mr. Lassell, 559; size of, compared with other planets, 119; vaporous atmosphere of, 333; weight of, 333 Newall, Mr. H.F., and Capella, 487; and the values of velocity of stars, 483 Newcomb, Professor, 9, 264, 267, 522 Newton, Professor, and meteoric showers, 377, 384 Newton, Sir Isaac, discovery of gravitation verified Kepler's laws, 144; dynamical theory, 214; illustrations of his teaching, 144–147; law of gravitation and, 125, 126, 537; parabolic path of comets and, 338–340; reflecting telescope, 19; weight of the Earth and, 203 Nickel in the Sun, 50 Nineveh, astronomers of, 156 Nordenskjöld, and the Ovifak meteorite, 407 Nova Cygni, 431; brilliancy of, 454; decline of, 455; distance of, 456; parallax of, 455 November meteors, 376, 377, 379 Nutation, and Bradley, 501 O Oberon, 309, 559 Object-glasses, 11, 12, 14, 16, 19 Observatories, 9–28 Observatory, Cape of Good Hope, 27; Dunsink, 12, 184; Greenwich, 26, 314; Lick, 16; Paris, 22; Uraniborg, 10; Vienna, 14; Washington, 226; Yerkes, 16 Occultation, 102, 215 Oceanus Procellarum, 83 Opera-glass, 27, 28 Opposition of Mars, 209 Orbital moment of momentum, 552 Orbits of planets, 114, 115, 117; dimensions, 139–143; elliptical form, 138–140; minor planets, 232, 234, 239; not exactly circles, 135; of satellites of Uranus, 310; Sun the common focus, 139 Orgueil meteorite, the, 399 Orion, 4, 418 Orion, belt of, 418, 467; brilliancy of, 418; nebula in, 269, 461, 466–469 Orionis, α, 418, 482 Orionis, θ, a multiple star, 318, 467 Ovifak meteorite, the, 407 P Palisa and the minor planets, 234 Pallas, 233, 238 Parabolic path of comets, 338–340 Parallactic ellipse, 444 Parallax, 181, 182, 214, 443; of stars, 507 Paris telescope, 22, 23 Pegasus, great square of, 413, 414 Peg-top, the, and the rotation of the Earth, 494 Pendulum for determining the force of the Earth's attraction, 205 Penumbra of Sun-spot, 51 Perihelion, 163 Periodic times of planets, 139–143, 558 Periodicity of Sun-spots, 41 Perseids, 400 Perseus, 415, 416, 429; sword-handle, 462 Perturbation, planetary, 317–324, 346 Perturbations, theory of, 296 Petavius, 93 Peters, Professor, and charts of minor planets, 234; and the derangement of Sirius, 427 Phases of the Moon, 71, 76 Phobos, 226, 551, 558 Photography, and practical astronomy, 25; and the distance of 61 Cygni, 449; Dr. Roberts and the nebula in Andromeda, 469; Mr. Common and the nebula in Orion, 469; Sir W. Huggins and the spectra of nebulæ, 473 Photosphere, the, 37, 54 Physical nature of the stars, 477 Piazzi, discoverer of the first known minor planet, 203 Pickering, Professor, 218, 220, 255, 265; and Betelgeuze, 482; and planetary nebulæ, 474; and Saturn's satellites, 296; and spectroscopic binaries, 486, 487 Pico, 89 Planetary motion, Kepler's laws of, 138, 141, 142, 147, 148 Planetary nebulæ, 470 Planetary perturbation, 317–324 Planets, ancient ideas respecting, 2, 6; approximate number of, 112; attract each other, 148, 317; attracted by comets,360; Bode's law, 230; comparative sizes of, 118, 119; distance of, from the Earth, 109–111; distance of, from the Sun, 558; how distinguished from stars, 111; irregularity of motions of, 317–324; Lagrange's theory of rigidity of, 531; light of, derived from the Sun, 113; minor, 229–244; orbits of the four giant, 117; orbits of the four interior, 114; orbits have their focus in the centre of the Sun, 139; orbits not exactly circles, 135; orbits take the form of an ellipse, 136–138; origin of, as suggested by the nebular theory, 526; periodic times of, 139–143, 558; relative distances of, 229; uniformity of direction in their revolution, 120, 322; velocity of, 139–142, 144, 146, 237 Plato (lunar crater), 89 Pleiades, 241, 416; invisible in the summer, 416 Pliny, the tides and the Moon, 535 Plough, the, 28 Pogson, Mr., 390 Pointers in the Great Bear, 28, 411 Polar axis, 196 Polar caps on Mars, 218, 219 Pole, the, distance of from Pole Star lessening, 494; elevation of, 195; movement of, 492; near α Draconis, 494; near Vega or α Lyra, 494 Pole Star, 194; belongs to the Little Bear, 412; distance of, from the pole of the heavens, 412, 492, 494; position of, 411; slow motion of, 412 Pollux, 420, 480; value of velocity of, 484 Pons, and the comet of 1818, 345 Posidonius, 87 Potassium in the Sun, 50 Præsepe, 422 Precession and nutation of the Earth's axis, 492–502 Proctor, and the stars in Argelander's atlas, 476 Prism, the, 45; its analysing power, 46 Pritchard, Professor, stellar photographic researches of, 449 Procyon, 420; value of velocity of, 484 Prominences on the Sun, 53–59 Ptolemy, his theory of astronomy, 6; lunar crater named after him, 92 Q Quarantids, the, 400 R Radius of the Earth, 193, 512 Rainbow, the, 45 Ram, the, 420 Reflectors, 19, 21, 25 Refraction by the prism, 45 Refractors, 11, 14, 16 Regulus, 421, 479 Reservoir formed from tidal water, 538 Retina, the, and the telescope, 10, 11 Rhea, 559 Rigel, 418, 420, 480 Rigidity of the planets, 532, 533 Roberts, Dr. Isaac, and the nebula in Andromeda, 469; and the nebula in Orion, 469 Roemer, and the velocity of light, 261 Romance, planet of, 151–154 Rosse telescope, the, 19, 20, 468, 470 Rotational moment of momentum, 553 Rowland, Professor, and spectral lines, 491 Rowton Siderite, 395 Royal Astronomical Society and Bessel, 442 S Sappho, 242 Satellites of Jupiter, 249, 250, 257–261, 266, 559; confirmation of the Copernican theory, 267 Satellites of Mars, 209, 225–228, 551, 558 Satellites of Neptune, 334, 559 Satellites of Saturn, 559; Bond's discoveries, 296; Cassini's discoveries, 294; distances, 559; Herschel's discoveries, 295; Huyghens' discovery, 293; Kirkwood's deduction, 296; Lassell's deduction, 296; movements, 296; origin as suggested by the nebular theory, 526 Satellites of Uranus, 308, 309, 310, 559 Saturn, ancient study of, 6; attraction on Uranus, 322; axial rotation of, 558; beauty of, 209; comparative proximity to the Earth of, 110; density of, 558; diameter of, 271, 558; distance of, from the Sun, 268, 271, 558; elliptic path of, 271; gravitation paramount, 283; internal heat of, 272, 515; Leonids and, 386; low density of, 272; moment of momentum of, 554; motion of, 271; orbit of, 117, 118; path of, perturbed by the attraction of Jupiter, 316; periodic time of, 558; period of revolution of, 269; picturesqueness of, 291; position of, in the solar system, 269; rings of, 269; rings, Bonds discovery, 280; rings, Cassini's discovery, 278; rings, consistency, 286; rings, Dawes's discovery, 281; rings, Galileo's discovery, 273, 274; rings, Hadley's observations, 282; rings, Herschel's researches, 279; rings, Huyghens' discovery, 275–278; rings, Keeler's measurement of the rotation, 288; rings, Maraldi's researches, 279; rings, rotation of, 285, 288; rings, spectrum of, 291; rings, Trouvelot's drawing, 278; satellites of, 293, 294, 295, 296, 559; size of, compared with other planets, 119, 269, 272; spectrum of, 291; unequal in appearance to Mars and Venus, 269; velocity of, 271; weight of, compared with the Earth, 272 Savary and binary stars, 436 Schaeberle, Mr., and Mars, 224 Scheiner, and the values of velocity of stars, 483; observations on Sun-spots, 36 Schiaparelli, Professor, and Mars, 220; and the connection between shooting-star showers and comets, 388; and the rotation of Mercury, 165 Schickard, 90 Schmidt, and Nova Cygni, 454, 489; and the crater Linné, 87; and the Leibnitz Mountains, 93 Schröter, and the crater Posidonius, 87 Schwabe, and Sun-spots, 40 Seas in the Moon, 82 Secchi, and stellar spectra, 479 Shoal of shooting stars, 377; dimensions, 377 Shooting stars (see Stars, shooting) Sickle, the, 421 Sidereal aggregation theory of Sir W. Herschel, 529 Siderite, Rowton, 395 Sinus Iridum, 83 Sirius, change in position of, 425; companion of, 427, 428; exceptional lustre of, 110; irregularities of movement of, 426; larger than the Sun, 110; most brilliant star, 419; periodical appearances of, 157; proper motion of, 425; spectrum of, 479; velocity of, 426; weight of, 427 Smyth, Professor C.P., 493 Sodium, colour of flame from, 49; in the Sun, 50 Solar corona, prominences etc. (see under Sun) Solar system, 107–121; Copernican exposition of the, 7; influence of gravitation on, 149; information respecting, obtained by observing the transit of Venus, 174; island in the universe, 121; minor planets, 229–244; moment of momentum, 554; movement of, towards Lyra, 457; origin of, as suggested by the nebular theory, 526; position of Saturn and Uranus in, 297, 305 South, Sir James, 12 Spectra of stars, 479 Spectro-heliograph, 58 Spectroscope, 43–56; detection of iron in the Sun by the, 50 Spectroscopic binaries, 487 Spectrum analysis, 47; dark lines, 49, 50; gaseous nebulæ, 474; line D, 48, 49 Speculum, the Rosse, 20 Spica, 423, 487 Spider-threads for adjusting the micrometer, 86; for sighting telescopes, 22 Spots on the Sun, 36–43; connection with magnetism, 42; cycles, 41; duration, 41; epochs of maximum, 42; motion, 36; period of revolution, 40; Scheiner's observations, 36; zones in which they occur, 39 Star clusters, 461–464; in Hercules, 462; in Perseus, 462 Stars, apparent movements due to precession, nutation, and aberration, 504; approximate number of, 28; attraction inappreciable, 316; catalogues of, 310, 311, 409, 431; charts of, 325, 328; circular movement of, 505–507 Stars, distances of, 441; Bessel's labours, 442–449; Henderson's labours, 442; method of measuring, 443–445; Struve's work, 442, 448, 449; parallactic ellipse, 444–449 Stars, double, 434; Bode's list, 435; Burnham's additions, 439; Cassini, 434; Herschel, 435, 436; measurement, 435, 436; revolution, 436; Savary, 436; shape of orbit, 436; variation in colour, 438 Stars, elliptic movement of, 506; gravitation and, 149; how distinguished from planets, 111; physical nature of, 477; probability of their possessing a planetary system, 121; real and apparent movements of, 504; really suns, 32, 121 Stars, shooting, attractions of the planets, 386; connection with comets, 388–390; countless in number, 372; dimensions of shoal, 377; features of, 373; length of orbit, 387; orbit, 378; orbit, gradual change, 386; period of revolution, 384; periodic return, 378, 379; shower of November, 1866, 377, 379–380; shower of November, 1866, and Professor Adams, 384, 386; shower of November, 1866, radiation of tracks from Leo, 380; shower of November, 1872, 389; showers, 376; showers and Professor Newton, 377; track, 377; transformed into vapour by friction with the Earth's atmosphere, 374, 376; velocity, 373, 386 Stars, spectra of, 479; teaching of ancients respecting, 3; temperature of, 515; temporary, 430, 488; values of velocity of, 484; variable, 429 Stoney, Dr. G.J., 387 Strontium, flame from, 46; in the Sun, 50 Struve, Otto, and the distance of Vega, 442, 447; and the distance of 61 Cygni, 448, 449 Sun, The, and the velocity of light, 265; apparent size of, as seen from the planets, 117, 118; as a star, 32; axial rotation of, 558; compared with the Earth, 29; connection of, with the seasons, 4; corona of, during eclipse, 62–64; density of, 65, 558; diameter of, 558; distance of, from Mars, 213; distance of, from Saturn, 271; distance of, from the Earth, 31, 114, 184, 240, 558; eclipse of, 6, 53; ellipticity of, 558; faculæ on surface of, 37; focus of planets' orbits, 138; gradually parting with its heat, 95; granules on surface of, 34; heat of, and its sources, 515–526; heat of, thrown on Jupiter, 256; minor planets and, 240; movement of, towards Lyra, 457; nebular theory of its heat, 526; photographed, 34; precession of the Earth's axis, 497; prominences of, 53–59; relation of, to the Moon, 71; rising and setting of, 2; rotation of, 40, 201; size of, 29; spectrum of, 48; spots on, 36–43; spots, connection with magnetism, 42; storms and convulsions on, 42, 43; surface of, gaseous matter, 34; surface of, mottled, 34; teaching of early astronomers concerning, 3–7; temperature of, 30, 31, 516; texture of, 34; tides on, 530; velocity of, 484; weight of, compared with Jupiter, 250, 350; zodiacal light and, 67; zones on the surface of, 39 Sunbeam, revelations of a, 44 Swan, the, 424, 439, 445 Sword-handle of Perseus, 462 Syrtis major, 222 T Taurus, constellation of, 231, 419 Tebbutt's comet, 353 Telescope, construction of the first, 10; equatorial (Dunsink), 12–14, 185; Greenwich, 26; Herschelian, 19; Lick, 16, 19; Paris, 22, 23; reflecting, 19, 21; refracting, 11, 14; Rosse, 19, 20, 468, 470; sighting of a, 23; structure of the eye illustrates the principle of the, 10; Vienna, 14–16; Washington, 226; Yerkes, 16 Temporary stars, 430, 488 Tethys, 559 Theophilus, 92 Tides, The, actual energy derived from the Earth, 539; affected by the law of gravitation, 149, 535; affected by the Moon, 70, 535–537; at Bay of Fundy, 538; at Cardiff, 538; at Chepstow, 538; at London, 538; at St. Helena, 538; excited by the Sun, 537; formation of currents, 538; in Bristol Channel, 538; in Mediterranean, 537; in mid-ocean, 538; Jupiter and, 552; length of the day and, 541; lunar, 548, 549; moment of momentum and, 552; neap, 537; rotation of the Earth, and revolution of the Moon, 549; satellites of Mars, 551; solar, 550; spring, 537; variations in, 538; waste of water power, 538; work effected, 539 Tin in the Sun, 50 Titan, 294, 295, 559 Titania, 309, 559 Transit of Mercury, 152, 163, 164 Transit of Venus, 152; Captain Cook, 184; Copeland's observations of, 189; Crabtree's observations of, 180; Gassendi's observations of, 178; Halley's method, 180, 181; Horrocks' observations of, 179, 180; importance of, 173; Kepler's prediction of, 163; observations of, at Dunsink, 184–188 Transit of Vulcan, 152–153 Triesnecker, 84, 93 Trouvelot, Mr. L., and Saturn's rings, 278 Tschermak, and the origin of meteorites, 400, 401 Tycho (lunar crater), 91 Tycho Brahe, and the Observatory of Uraniborg, 9, 10, 430 U Umbra of Sun-spot, 51 Umbriel, 309, 559 Unstable dynamical equilibrium, 543 Uraniborg, Observatory of, 10 Uranus, 112; attraction of Saturn, 322; Bradley's observations of, 312; composition of, 308; density of, 558; diameter of, 308, 558; diameter of orbit of, 305; disc of, 308; discovery of, by Herschel, 305, 308; distance from Sun of, 558; ellipse of, 313; first taken for a comet, 304; Flamsteed's observations of, 311, 312; formerly regarded as a star, 311, 312; investigations to discover a planet outside the orbit, 323–324; irregular motion of, 314, 323; Lemonnier's observations of, 312; Leonids and, 386; Mayer's observations of, 312; moment of momentum of, 554; orbit of, 117, 310; periodic time of, 558; period of revolution of, 312; rotation of, 308; satellites of, 559; satellites, discovery by Herschel, 308; satellites, movement nearly circular, 309; satellites, periodical movements, 309; satellites, plane of orbits, 309, 310; size of compared with the Earth, 308; and with other planets, 119; subject to another attraction besides the Sun, 314 Ursa major (see Great Bear) V Variable Stars, 429 Vega, 414, 423, 424, 479; Struve's measurement of, 442 Velocity, of light, 261, 262, 265; of light, laws dependent upon, 511; of planets, 140–143, 146, 237; of stars, values of, 483–4 Venus, ancient study of, 6; aspects of, 171; atmosphere of, 189; brilliancy of, 168; density of, 558; diameter of, 191, 558; distance of, from the Sun, 191, 558; habitability of, 173; movement of, 168; neighbour to the Earth, 109; orbit of, 114, 135; orbit form of, 139, 191; periodic time of, 558; a planet or "wanderer," 111; rotation of, 191; shape of, 169; size of, compared with other planets, 116, 169; surface of, 171; transit of, 152, 176–190; transit, importance of, 173; transit predicted by Kepler, 163; velocity and periodic time of, 142, 143, 191; view of the ancients about, 157 Vesta, 233, 238 Victoria, 242 Vienna telescope, 14–16 Virgo, 423 Vogel and Algol, 485; and Spica, 486, 487; and the spectra of the stars, 479, 483 Volcanic origin of meteorites, 400; outbreaks on the Earth, 197 Von Asten and Encke's comet, 349, 350; and the distance of the Sun, 351; and the weight of Mercury, 166 Vortex rings, 469 Vulcan, 152, 153; and the Sun, 3 W Wargentin, 90 Watson, Professor, and Mercury, 154 Watson, Sir William, friendship with Herschel, 302 Wave-lengths, 60 Weather, not affected by the Moon, 82 Wilson, Mr. W.E., and the nebula in Orion, 469 Witt, Herr G., and Eros, 236 Wold Cottage meteorite, the, 392 Wright, Thomas, and the Milky Way, 474 Y "Year of Stars," the, 377 Yerkes Observatory, Chicago, 16 Young, Professor, account of a marvellous Sun-prominence, 42; and Sun-spots, 38; observations on magnetic storms, 39 Z Zeeman, Dr., and spectral lines, 491 Zinc in the Sun, 50 Zodiac, the, 5 Zodiacal light, 67 Zone of minor planets, 234

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