Appendix Ii

The following list includes a number of double and multiple stars, clusters, and nebulæ, which may be fairly well seen with instruments up to 3 inches in aperture. A few objects have been added on account of their intrinsic interest, which may prove pretty severe tests. The places given are for 1900, and the position-angles and distances are mainly derived from Mr. Lewis's revision of Struve's 'Mensuræ Micrometricæ,' Royal Astronomical Society's Memoirs, vol. lvi., 1906. For finding the various objects, Proctor's larger Star Atlas, though constructed for 1880, is still, perhaps, the most generally useful. Cottam's 'Charts of the Constellations' (Epoch 1890) are capital, but somewhat expensive. A smaller set of charts will be found in Ball's 'Popular Guide to the Heavens,' while Peck has also published various useful charts. The student who wishes fuller information than that contained in the brief notes given below should turn to Gore's exceedingly handy volume, 'The Stellar Heavens.'

The brighter stars are generally known by the letters of the Greek alphabet, prefixed to them by Bayer. When these are used up, recourse is had either to the numbers in Flamsteed's Catalogue, or to those in Struve's 'Mensuræ Micrometricæ.' The Struve numbers are preceded by the Greek [Sigma]. A few of the more notable variable and red stars are included; these are generally marked by capital letters, as V. AQUILÆ. The order of the notes is as follows. First is given the star's designation, then its place in hours and minutes of right ascension and degrees and minutes of declination, N. and S. being marked respectively by + and -; then follow the magnitudes; the position-angles, which are measured in degrees from the north, or bottom point of the field, round by east, south, and west to north again; the distances of the components from one another in seconds of arc; and, finally, short notes as to colour, etc. According to Dawes, one inch aperture should separate the components of a 4·56″ double star, two inches those of a 2·28″, three those of a 1·52″, and so on. If the observer's glass can do this on good nights there is little fault to find with it. Double stars may be difficult for other reasons than the closeness of the components; thus, a faint companion to a bright star is more difficult to detect than a companion which is not far below its primary in brightness. Clusters and nebulæ, with a few exceptions, are apt to prove more or less disappointing in small instruments. The letters of the Greek alphabet are as follows:

ANDROMEDA.

M. 31: 0 h. 37 m. + 40° 43′. Great Spiral Nebula. Visible to naked eye near Andromedæ. Rather disappointing in small glass.

AQUARIUS.

M. 2 : 21 h. 28 m. - 1° 16′. Globular cluster; forms flat triangle with [alpha] and .

AQUILA.

M. 11 : 18 h. 46 m. - 6° 23′. Fine fan-shaped cluster. Just visible to naked eye.

V : 18 h. 59 m. - 5° 50′. Red star, variable from 6·5 to 8·0.

ARGO NAVIS.

M. 46 : 7 h. 37 m. - 14° 35′. Cluster of small stars, about 1/2° in diameter.

ARIES.

AURIGA.

(Capella) [alpha] : 5 h. 9 m. + 45° 54′. Spectroscopic binary; period 104 days.

M. 37 : 5 h. 46 m. + 32° 31′. Fine cluster. M. 36 and M. 38 also fine. All easily found close to straight line drawn from [kappa] to Aurigæ.

: 5 h. 52 m. + 44° 57′. Spectroscopic binary, period 3·98 days.

41: 6 h. 4 m. + 48° 44′ : 5·2-6·4 : 353·7 : 7·90″. Yellowish-white, bluish-white.

BOÖTES.

CAMELOPARDUS.

V. : 3 h. 33 m. + 62° 19′. Variable, 7·3 to 8·8. Fiery red.

CANCER.

Præsepe: Cluster, too widely scattered for anything but lowest powers.

CANES VENATICI.

M. 51 : 13 h. 26 m. + 47° 43′. Great spiral. 3° S.W. of Ursæ Majoris.

M. 3 : 13 h. 38 m. + 28° 53′. Fine globular cluster; on line between Cor Caroli and Arcturus, rather nearer the latter.

CANIS MAJOR.

M. 41 : 6 h. 43 m. - 20° 38′. Fine cluster, visible to naked eye, 4° below Sirius.

CANIS MINOR.

(Procyon) [alpha] : 7 h. 34 m. + 5° 30′ : 0·5-14 : 5° 4·46″. Binary, companion discovered, Lick, 1896, only visible in great instruments.

CAPRICORNUS.

M. 30 : 21 h. 35 m. - 23° 38′. Fairly bright cluster.

CASSIOPEIA.

H. vi. 30 : 23 h. 52 m. + 56° 9′. Large cloud of small stars.

CEPHEUS.

S : 21 h. 36 m. + 78° 10′. Variable, 7·4 to 12·3. Very deep red.

CETUS.

(Mira) [omicron] : 2 h. 14 m. - 3° 26′. Variable. Period about 331 days. Maxima, 1·7 to 5; minima, 8 to 9. Colour, deep yellow to deep orange.

COMA BERENICES.

M. 53 : 13 h. 8 m. + 18° 42′. Cluster of faint stars.

CORONA BOREALIS.

R : 15 h. 44 m. + 28° 28′. Irregularly variable, 5·5 to 10·1.

CORVUS.

CRATER.

R. : 10 h. 56 m. - 17° 47′. Variable. About 8 magnitude. Almost blood-colour.

CYGNUS.

(Albireo) : 19 h. 27 m. + 27° 45′ : 3-5·3 : 55° : 34·2″. Orange-yellow, blue. Easy and beautiful.

Z : 19 h. 58 m. + 49° 45′. Variable, 7·1 to 12. Deep red.

RS : 20 h. 10 m. + 38° 27′. Variable, 6 to 10. Deep red.

U : 20 h. 16 m. + 47° 35′. Variable, 7 to 11·6. Very red.

V : 20 h. 38 m. + 47° 47′. Variable, 6·8 to 13·5. Very red.

RV : 21 h. 39 m. + 37° 33′. Variable, 7·1 to 9·3. Splendid red.

DELPHINUS.

V : 20 h. 43 m. + 18° 58′. Variable, 7·3 to 17·3. Period 540 days. Widest range of magnitude known.

DRACO.

H. iv. 37 : 17 h. 59 m. + 66° 38′. Planetary nebula, nearly half-way between Polaris and [gamma] Draconis. Gaseous; first nebula discovered to be so.

EQUULEUS.

ERIDANUS.

GEMINI.

M. 35 : 6 h. 3 m. + 24° 21′. Magnificent cluster; forms obtuse triangle with and .

: 6 h. 58 m. + 20° 43′. Variable, 3·8 to 4·3. Period 10·2 days. Non-eclipsing binary.

(Castor) [alpha] : 7 h. 28 m + 32° 7′ : 2-2·8 : 224·3° : 5·68″. White, yellowish-green. Finest double in Northern Hemisphere.

HERCULES.

M. 13 : 16 h. 38 m. + 36° 37′. Great globular cluster, two-thirds of way from to .

M. 92 : 17 h. 14 m. + 43° 15′. Globular cluster; fainter than M. 13.

HYDRA.

V : 10 h. 47 m. - 20° 43′. Variable, 6·7 to 9·5. Copper-red.

W : 13 h. 44 m. - 27° 52′. Variable, 6·7 to 8·0. Deep red.

LACERTA.

LEO.

LEO MINOR.

LEPUS.

R : 4 h. 55 m. - 14° 57′. Variable, 6·7 to 8·5. Intense crimson.

LIBRA.

M. 5 : 15 h. 13 m. + 2° 27′. Globular cluster, close to star 5 Serpentis. Remarkable for high ratio of variables in it--1 in 11.

LYNX.

LYRA.

T : 18 h. 29 m. + 36° 55′. Variable, 7·2 to 7·8. Crimson.

(Vega) [alpha] : 18 h. 34 m. + 38° 41′ : 1-10·5 : 160° : 50·77″. Very pale blue. The faint companion is a good test for small telescopes. Vega is near the apex of the solar way.

{ [epsilon]^1 : 18 h. 41·1 m. + 39° 30′ : 4·6-6·3 : 12·4° : 2·85″. [epsilon] { Pale yellow, pale orange yellow. { [epsilon]^2 : 4·9-5·2 : 127·3° : 2·15″. Both pale yellow.

: 18 h. 41 m. + 37° 30′ : 4·2-5·5 : 150° : 43·7″. Easy, both pale yellow.

: 18 h. 46 m. + 33° 15′ : 3-6·7 : 149·8° : 45·3″. 3 variable, 12·91 days. Spectroscopic binary.

M. 57 : 18 h. 50 m. + 32° 54′. Ring Nebula, between and [gamma]. Faint in small telescope. Gaseous.

MONOCEROS.

OPHIUCHUS.

: 16 h. 19 m. - 23° 13′ : 6-6 : 355° : 3·4″.

39 : 17 h. 12 m. - 24° 11′ : 5·5-6 : 358° : 15″. Pale orange, blue.

ORION.

(Rigel) : 5 h. 10 m. -8° 19′ : 1-8 : 202·2° : 9·58″. Bluish-white, dull bluish. Fair test for small glass.

M. 42 : 5 h. 30 m. - 5° 28′ : 6-7-7·5-8. Great Nebula of Orion.

: 5 h. 36 m. - 2° 0′ : 2-6 : 156·3° : 2·43″. Yellowish-green, blue.

U : 5 h. 50 m. + 20° 10′. Variable, 5·8-12·3. Period 375 days.

PEGASUS.

M. 15 : 21 h. 25 m. + 11° 43′. Fine globular cluster, 4° N.E. of [delta] Equulei.

PERSEUS.

H. VI. 33·34 : 2 h. 13 m. + 56° 40′. Sword-handle of Perseus. Splendid field.

M. 34 : 2 h. 36 m. + 42° 21′. Visible to naked eye. Fine low-power field.

(Algol) : 3 h. 2 m. + 40° 34′. Variable, 2·1 to 3·2. Period 2·8 days. Spectroscopic eclipsing binary.

PISCES.

SAGITTA.

SAGITTARIUS.

M. 20 : 17 h. 56 m. - 23° 2′. The Trifid Nebula.

SCORPIO.

: 15 h. 59·6 m. - 19° 31′ : 2-5 : 25° : 13·6″. Orange, pale yellow.

(Antares) [alpha] : 16 h. 23 m. - 26° 13′ : 1-7 : 270° : 3″. Difficult with small glass.

SCUTUM SOBIESKII.

M. 24 : 18 h. 12 m. - 18° 27′. Fine cluster of faint stars on Galaxy.

M. 17 : 18 h. 15 m. - 16° 14′. The Omega Nebula. Gaseous.

R : 18 h. 42 m. - 5° 49′. Irregular, variable, 4·8 to 7·8.

SERPENS.

SEXTANS.

TAURUS.

M. 1 : 5 h. 28 m. + 21° 57′. The Crab Nebula. Faint in small glass.

TRIANGULUM.

URSA MAJOR.

(Mizar) : 13 h. 20 m. + 55° 27′ : 2·1-4·2 : 149·9° : 14·53″. Fine pair, yellow and yellowish-green. Alcor, 5 magnitude in same field with low power, also 8 magnitude star.

URSA MINOR.

(Polaris) [alpha] : 1 h. 22 m. + 88° 46′ : 2-9 : 215·6° : 18·22″. Yellow, bluish, test for 2-inch.

VIRGO.

VULPECULA.

M. 27 : 19 h. 55 m. + 22° 27′. The Dumb-bell Nebula. Just visible with 1-1/4-inch. Gaseous.

INDEX

Achromatic. See Telescope

Adams, search for Neptune, 198-201

Aerolites, 227

Airy, search for Neptune, 197-201

Albireo, colour of, 236

Alcor, 241

Alcyone, 256

Aldebaran, 234; colour of, 235

Algol, spectroscopic binary, 246; diameter and mass of components, 246; period of, 250; variables, 250

Alps, lunar, 116; valley of, 116, 117

Altai Mountains, 117

Altair, 234

Altazimuth, 25-28

Anderson discovers Nova Aurigæ, 253; discovers Nova Persei, 254

Andromeda, great nebula of, 263, 264

Andromedæ [gamma], colour of, 236

Andromedes, 214, 215, 225, 226

Annular eclipse, 69, 70

Antares, 234

Anthelme observes new star, 252

Apennines, lunar, 116

Archimedes, 117

Arcturus, 234

Argelander, number of stars, 235

Ariadæus cleft, 119

Arided, 234

Arietis [gamma], observed by Hooke, 240

Aristillus, 117

Asteroids, number of, 150; methods of discovery, 150, 151

Asterope, 256

Astræa, discovery of, 150

Atlas, 256

Atmosphere, solar, 75

Autolycus, 117

Auzout, aerial telescopes, 4

Bacon, Roger, 1

Bailey, cluster variables, 259

Ball, Sir R., 154, 262; 'Popular Guide to the Heavens,' 278

Barnard, measures of Venus, 89; markings on Venus, 95; on Mars, 133; measures of asteroids, 152; discovers Jupiter's fifth satellite, 167; measures of Saturn, 172; drawing of Saturn, 172; rotation of Saturn, 174; on Saturnian markings, 184-185; observation of Comet 1882 (iii.), 218

Bayer, lettering of stars, 278

Beer. See Mädler

Bélopolsky, rotation of Venus, 96

Bessel, search for Neptune, 197

Betelgeux, 234; colour of, 235

Biela's comet, 213, 214, 215, 224, 225

Birmingham observes Nova Coronæ, 252

Bode's law, 148, 149

Bond, G. P., discovers rifts in Andromeda nebula, 264

Bond, W. C., discovers Crape Ring, 178; discovers Saturn's eighth satellite, 187; verifies discovery of Neptune's satellite, 201

Boötis [epsilon], double star, 242

Bouvard, tables of Uranus, 197

Bradley uses aerial telescope, 4

Bremiker's star-charts, 200

Brooks' comet, 210; observation of comet 1882 (iii.), 218

Brorsen's comet, 213

Calcium in chromosphere, 73

Campbell, atmosphere of Mars, 140; bright projections on Mars, 141; spectroscopic investigation of Saturn's rings, 180

Canals. See Mars

Canes Venatici, great spiral nebula in, 265

Canopus, 234

Capella, 234

Capricorni [alpha], naked-eye double, 241

Carpathians, 117

Carrington, solar rotation, 59

Cassegrain. See Telescope, forms of

Cassini uses aerial telescope, 4; discovers four satellites of Saturn and division of ring, 4; observations on Jupiter, 160; discovers division in Saturn's ring, 177; four satellites of Saturn, 184, 186, 187

Cassiopeiæ , double star, 242; Nova, 252

Castor, 234; double star, 242; binary, 245

Caucasus, lunar, 116

Cauchoix constructs 12-inch O.G., 6

Celaeno, 256

Celestial cycle, 18

Centauri [alpha], 231, 234

Ceres, discovery of, 149; diameter of, 152; reflective power, 152

Ceti , naked-eye double, 241; Mira ([omicron]) variable star, 248; period, 249

Challis, search for Neptune, 199

Chambers, G. F., on comets, 208-209; number of comets, 209

Chromosphere, 71, 73, 76; depth of, 73; constitution of, 73

Clark, Alvan, constructs 18-1/2-inch, 8; 26-inch, 8; 30-inch Pulkowa telescope and 36-inch Lick, 8; 40-inch Yerkes, 9

Clavius, lunar crater, 113, 114, 120

Clerke, Miss Agnes, 60, 73; climate of Mercury, 85; on Mars, 139; albedo of asteroids, 152; Jupiter's red spot, 161; on comet 1882 (iii.), 218; on Mira Ceti, 248

Clerk-Maxwell, constitution of Saturn's rings, 179

Cluster variables, 259

Clusters, irregular, 256; globular, 258

Coggia's comet, 211

Coma Berenices, 256

Comas Solà, rotation of Saturn, 174

Comet of 1811, 206; of 1843, 206, 215, 216; of Encke, 207; of Halley, 207, 213; Brooks, 210; Donati, 205, 210; Tempel, 211; 1866 (i.), 214, 224; Winnecke, 211; Coggia, 211; Holmes, 211; Biela, 213; and Andromeda meteors, 214, 215, 224, 225; great southern (1901), 211; Wells, 213; of 1882, 213, 216-219; De Vico, 213; Brorsen, 213; of Swift 1862 (iii.), and Perseid meteors, 214, 224; great southern (1880), 216; of 1881, 216; of 1807, 216

Comets, 203 et seq.; structure of, 205; classes of, 206-208; number of, 209; spectra of, 211-213, 218; constitution of, 212, 218; connection with meteors, 214, 215, 224; families of, 215-218; observation of, 219-222

Common 5-foot reflector, 12; photographs Orion nebula, 262

Constellations, formation of, 237, 238

Contraction of sun, 79

Cooke, T., and Sons, 25-inch Newall telescope, 8; mounting of 6-inch refractor, 31

Copernicus, prediction of phases of Venus, 92; lunar crater, 114; ray system of, 120, 121

Corona, 71, 72, 76; tenuity of, 71; variations in structure, 71; minimum type of, 71, 72; maximum type of, 72; constitution of, 72

Corona Borealis, 238; Nova in, 252

Coronal streamers, analogy with Aurora, 71

Coronium, 72, 73

Cottam, charts of the constellations, 278

Crape ring of Saturn, 178

Craters, lunar, 109, 112; ruined and 'ghost,' 111; number and size, 112; classification of, 112

Cygni, 61, 231; [alpha], 234; , colour of, 236

Darwin, G. H., evolution of Saturnian system, 186

Dawes discovers crape ring, 178; search for Neptune, 199, 200

Deimos, satellite of Mars, 143

Delphinus, 237

Denning, absence of colour in reflector, 22; measuring sun-spots, 51, 53; on naked-eye views of Mercury, 82; abnormal features on Venus, 94; on canals of Mars, 136; observations of cloud on Mars, 139, 140; changes on Jupiter, 159, 160; rotation of Saturn, 174; visibility of Cassini's division, 182; number of meteor radiants, 225; classification of sporadic meteors, 227; meteoric observation, 227, 228; stationary radiants, 229

Deslandres, calcium photographs of sun, 60; on form of corona, 72; photographs chromosphere and prominences, 74

De Vico's comet, 213

Dew-cap, 39

Digges, supposed use of telescopes, 1

Dollond, John, invention of achromatic, 5; 5-foot achromatics, 6

Donati, comet of 1858, 205, 210; spectrum of comet Tempel, 211

Doppler's principle, 180

Dorpat refractor, 6, 7, 31

Douglass, markings on Venus, 95

Draco, planetary nebula in, 266

Dunér, rotation of sun, 59

Earth-light on moon, 105

Eclipse, Indian, 1898, 70; 1878, July 29, 72; 1870, December 22, 74

Eclipses, solar, 68-70; of moon, 105, 106

Electra, 256

Electrical influence of sun on earth, 63

Elger on lunar Maria, 111; lunar clefts, 119; lunar chart, 125

Elkin observes transit of comet 1882 (iii.), 212

Encke discovers division in ring of Saturn, 177; search for Neptune, 200

Equatorial mountings, 29-31, 36

Equulei [delta], short-period binary, 245

Erck, Dr. Wentworth, satellites of Mars, 144

Eros, discovery of, distance of, 151; variability of, 152

Fabricius observes Mira Ceti, 248

Faculæ, 59; rotation period of, 59

Faculides, 60

Finder. See Telescope

Finlay, transit of comet 1882 (iii.), 212

Flamsteed, catalogue of stars, 278

Fomalhaut, 234

Fowler, 'Telescopic Astronomy,' 17

Fracastorius, 111

Galaxy. See Milky Way

Galilean telescope. See Telescope, forms of

Galileo Galilei, invention of telescope, 2; loss of sight, 47; discovery of phases of Venus, 92; on lunar craters, 112; discovers four satellites of Jupiter, 166; observations of Saturn, 175, 176

Galle discovers Neptune, 200

Gassendi observes transit of Mercury, 87; lunar crater, 119

Geminorum [alpha]. See Castor

George III. pensions Herschel, 193

Georgium Sidus, 194

Gore, period of Algol, 250; globular clusters, 259; 'The Stellar Heavens,' 278

Gregorian. See Telescope, forms of

Grubb, 27-inch Vienna telescope, 8; on telescopic powers, 41

Gruithuisen, changes on moon, 126

Hale, calcium photographs of sun, 60

Hall, Asaph, discovers satellites of Mars, 8, 143; rotation of Saturn, 173, 174

Hall, Chester Moor, discovers principle of achromatic, 5

Halley's comet, 207, 213

Harding discovers Juno, 149

Hebe, discovery of, 150

Hegel proves that there are only seven planets, 149

Helium in chromosphere, 73

Helmholtz, speed of sensation, 48; solar contraction, 79

Hencke discovers Astræa and Hebe, 150

Henry, 30-inch Nice telescope, 8

Heraclides promontory, 117

Hercules, 237

Herculis [alpha], double star, 242

Herodotus, valley of, 118, 119, 126

Herschel, Sir John, drawing of Orion nebula, 262

Herschel, Sir William, 4-foot telescope, 13; impairs sight, 47; misses satellites of Mars, 143, 144; rotation of Saturn, 173; discovers Saturn's sixth and seventh satellites, 186, 187; early history, 190, 191; discovers Uranus, 191; discovers two satellites of Uranus, 196; binary stars, 244; gaseous constitution of nebulæ, 260; distribution of nebulæ, 267; translation of solar system, 269

Herschelian. See Telescope, forms of

Hevelius, description of Saturn, 176

Hind discovers Nova Ophiuchi, 252

Hirst, colouring of Jupiter, 159

Hirst, Miss, colouring of Jupiter, 159

Holden on solar rotation, 59, 60

Holmes, Edwin, telescope-house, 38; comet, 211

Holmes, Oliver Wendell, 'Poet at the Breakfast-table,' 13

Holwarda observes [omicron] Ceti, 248

Hooke, observation of Gamma Arietis, 240

Howlett, criticism of Wilsonian theory of sun-spots, 61

Huggins, atmosphere of Mars, 140; gaseous nature of nebulæ, 210; spectrum of Winnecke's comet, 211; discovers nebula in Draco to be gaseous, 260; spectrum of Andromeda nebula, 264

Humboldtianum, Mare, 111

Humboldt observes meteor-shower of 1799, 224

Hussey, search for Neptune, 197

Hussey, W. J., period of [delta] Equulei, 245

Huygens, improvement on telescopes, 3; aerial telescopes, 4; discovers nature of Saturn's ring and first satellite of Saturn, 177, 186; observation of [theta] Orionis, 240; of great nebula in Orion, 261

Huygens, Mount, 116

Hydrogen in chromosphere, 73

Hyginus cleft, 119

Imbrium, Mare, 116

Iron in chromosphere, 73

Jansen, Zachariah, claim to invention of telescope, 1

Janssen, photographs of sun, 57

Journal of British Astronomical Association, 23, 38

Juno, discovery of, 149; diameter of, 152

Jupiter, brilliancy compared with Venus, 90; period of, 155; distance of, 155; diameter of, 155; compression, volume, density, 155; brilliancy, 156; apparent diameter of, 156; belts of, 157 et seq.; colouring, 158, 159; changes on surface of, 159, 160; great red spot, 160-164; rotation period, 163-165; resemblance to sun, 164-166; satellites of, 166-169; observation of, 169-171; visibility of satellites, 166; diameters of, 167; occultations of, eclipses of, transits of, 167

Kaiser sea, Mars, 145

Keeler, report on Yerkes telescope, 9; rotation of Saturn, 174; constitution of Saturn's rings, 180; photographic survey of nebulæ, 267

Kelvin, solar combustion, 78, 79

Kepler, suggestion for improved refractor, 3; predicts transit of Mercury, 87; lunar crater, ray-system of, 120, 121; observes new star, 252

Kirchhoff, production of Fraunhofer lines, 75

Kirkwood, theory of asteroid formation, 153; periodic meteors, 214

Kitchiner, visibility of Saturn's satellites, 188

Klein's Star Atlas, 255

Lampland, photographs of Mars, 137

Langley, heat of umbra of sun-spot, 50; changes in sunspots, 55

Lassell, 4-foot reflector, 37; discovers Saturn's eighth satellite, 187; discovers satellite of Uranus, 196; search for Neptune, 200; discovers satellite of Neptune, 201; drawing of Orion nebula, 262

Leibnitz, mountains, 117

Lemonnier, observations of Uranus, 193

Leonid, meteors, 214, 224, 225, 226

Leonis [gamma], colour of, 236

Leverrier, search for Neptune, 199-201

Lewis, revision of Struve's 'Mensuræ Micrometricæ,' 278

Lick, 36-inch telescope, 8

Light, speed of, 231

Light-year, 230

Lippershey, claim to invention of telescope, 1

Lohrmann, lunar chart of, 122

Lowell, rotation of Mercury, 85; surface of Mercury, 86; surface of Venus, 95; rotation of Venus, 96; 'oases' of Mars, 137, 138; projections on Mars, 141

Lunar observation, 123-125

Lyræ [epsilon], double double, 241, 242; , variable star, 249; spectroscopic binary, 250

Lyra, ring nebula in, 265; photographs of, 266

Lyrid, meteors, 214, 224, 226

M. 35, cluster, 257; M. 13, number of stars in, 258; M. 92, 259; M. 3 and M. 5, variables in, 259; M. 51, 265

MacEwen, drawing of Venus, 94, 95

Mädler, heights of lunar mountains, 118; lunar chart, 122, 124, 128

Maginus, 120

Magnesium in chromosphere, 73

Maia, 256

Maintenance of solar light and heat, 78, 79

Marius, Simon, description of Andromeda nebula, 264

Markwick, Colonel, 117

Mars, distance, diameter, rotation, year of, phase of, 130-132; oppositions of, 130, 131; polar caps, 132; canals, 135-137; dark areas, 133; 'oases,' 137, 138; atmosphere of, 139, 140; projections on terminator, 141; satellites of, 142-144; visibility of details of, 144

Maunder, Mrs., photographs of coronal streamers, 70

Maunder, E. W., adjustment of equatorial, 22, 23; electrical influence of sun on earth, 63; 'Astronomy without a Telescope,' 238

Mee, Arthur, on amateur observation, 17; visibility of Cassini's division, 183

Melbourne 4-foot reflector, 12

Mellor, lunar chart, 124

Mendenhall, illustration of sun's distance, 48

Mercury, elongations of, 81; diameter of, 82; orbit, 83; bulk, weight, density, reflective power, 83; phases, 84; surface, 84; rotation period, 85; transits, 87, 88; anomalous appearances in, 87

Merope, 256

Merz, Cambridge (U.S.A.), and Pulkowa refractors, 6

Messier, lunar crater, 126; 'the comet ferret,' 219; catalogue of nebulæ, 258

Meteors, 222 et seq.; shower of 1833, 223; of 1866, 224; Perseid, 214, 224, 225; Leonid, 214, 224, 225; Lyrid, 214, 224, 226; Andromedes, 214, 215, 224, 225; radiant point, 223, 224; sporadic, 226; observation of, 227-229

Metius's claim to invention of telescope, 1

Milky Way, 239; clustering of stars towards, 240; nebulæ in, 240

Mira, [omicron] Ceti, 248; period of, 249

Mizar, 240, 241

Montaigne, 219

Month, lunar and sidereal, 103

Moon, size, orbit, area, volume, density, mass, force of gravity, 100; lunar tides, 101, 102; phases, 102; synodic period, 103; reflective power, 104; 'old moon in young moon's arms,' 104; earth's light on, 105; lunar eclipses, 105, 106; 'black eclipses,' 105; Maria of, 109-111; craters of, 109, 112-114; mountain ranges, 109, 116-118; clefts or rills, 109, 118, 119; ray systems, 109, 120, 121; atmosphere of, 126; evidence of change, 127, 128

Mountings. See Telescope

Nasmyth, willow-leaf structure of solar surface, 57; lunar clefts, 119; on lunar ray systems, 121; and Carpenter, lunar chart, 125; on powers for lunar observation, 127

Nebula of Orion, 261-263; drawings of, 262; photographs, 262; distance of, 263; of Andromeda, 263, 264; photographs of, 264; spectrum, 264

Nebulæ, few in neighbourhood of Galaxy, 240; Messier's catalogue of, 258; gaseous, 260 et seq.; spiral, 263-265; ring, 265; planetary, 266; number of, 267

Neison on lunar walled plains, 115, 120; lunar chart, 125

Neptune, 148, 196 et seq.; diameter, distance, period, spectrum, satellite of, 201

Newall, 25-inch refractor, 8

Newcomb on scale of solar operations, 77, 78; on markings of Venus, 93; phosphorescence of dark side of Venus, 97; ratio of stellar increase, 235; 'Astronomy for Everybody,' 238; stars in galaxy, 240; spectroscopic binaries, 248; on Nova Persei, 254; on constitution of stars, 268; apex of solar path, 271

Newton, Sir Isaac, invents Newtonian reflector, 10

Nice, 30-inch refractor, 8

Nichol on M. 13, 258

Nilosyrtis, 145

Noble, method of observing sun, 67; visibility of Saturn's satellites, 188

Nova Cassiopeiæ, 252; Coronæ, 252; Cygni, 253; Andromedæ, 253; Ophiuchi, 252; Aurigæ, 253; spectrum of, 253; changes into planetary nebula, 254; Persei, 254; photographs of, 254; nebulosity round, 254; Geminorum, 255; colour, spectrum of, 255

Object-glass, treatment of, 19, 20; testing of, 20-23

Observation, methods of solar, 65-67

Olbers discovers Pallas and Vesta, 149; theory of asteroid formation, 150, 152

Oppolzer, E. von, discovers variability of Eros, 152

Opposition, 130 (note); of Mars, 130, 131

Orion, 237; great nebula of, 261-263

Orionis [theta], observation of, 240; , naked-eye double, 241; [theta], multiple star, 243; [sigma], multiple star, 243

Palisa discovers asteroids, 151

Pallas, discovery of, 149; diameter of, 152

Peck, 'Constellations and How to Find Them,' 238; star-charts, 278

Pegasi [kappa], short-period binary, 245

Pegasus, 237

Perihelion of planets, 131 (note)

Period, synodic, of moon, 103

Perrine discovers Jupiter's sixth and seventh satellites, 167

Perseid, meteors, 214, 224, 225

Perseus, sword-handle of, 257

Petavius cleft, 119

Peters discovers asteroids, 151

Phillips, Rev. T. E. R., polar cap of Mars, 134; canals of Mars, 137; clouds on Mars, 140

Phobos satellite of Mars, 143

Phosphorescence of dark side of Venus, 97

Photosphere, 75

Piazzi discovers Ceres, 149

Pickering, E. C., number of lucid stars in northern hemisphere, 233; parallax of Orion nebula, 262

Pickering, W. H., on lunar ray systems, 120, 121; changes on moon, 126; on polar cap of Mars, 134, 135; discovers Saturn's ninth and tenth satellites, 187; photographs Orion nebula, 262

Planetary nebulæ, 266; spectra of, 266; nebula in Draco, 266

Plato, 117, 126

Pleiades, number of stars in, 233, 256, 257; nebula of, 257

Pleione, 256

Polarizing eye-piece, 66

Pollux, 234

Præsepe, 256

Procellarum Oceanus, 111

Proctor, 2; method of finding Mercury, 82; on state of Jupiter, 166

Proctor on the Saturnian system, 181; visibility of Cassini's division, 182; on Challis's search for Neptune, 199; Star Atlas, 278

Procyon, 234

Projecting sun's image, 67

Projections on terminator of Mars, 141

Prominences, 73, 74

Ptolemäus, 112

Pulkowa, 30-inch refractor, 8, 9

Radiant point of meteors, 223, 224; number of, 225; stationary, 229

Ranyard Cowper on parallax measures, 231

Regulus, 234

Reversing layer seen by Young, 74; spectrum photographed by Shackleton, 75; depth of, 75

Riccioli observes duplicity of Ursæ Majoris, 240

Rigel, 232, 234; colour of, 235

Ritchey, 5-foot reflector Yerkes Observatory, 12

Roche's limit, 186

Rosse, Earl of, 6-foot reflector, 12; colouring of Jupiter, 158, 159; telescope, resolution of Orion nebula, 260; drawing of Orion nebula with, 262; spiral character of M. 51, 265

Rotation period of Mercury, 85; of Venus, 95, 96

Satellite of Venus, question of, 97, 98; of Mars, 142-144; of Jupiter, 166-169

Saturn, orbit of, sun-heat received by, period of, diameter of, compression and density of, 172; features of globe, rotation period, 173; varying aspects of rings, 178; measures of rings, 178; constitution of rings, 179; satellites of, 186-189; satellites, transits of, 189

Scheiner, construction of refractors, 2

Scheiner, Julius, spectrum of Andromeda nebula, 264

Schiaparelli, rotation of Mercury, 85; surface of Mercury, 86; rotation of Venus, 96; discovery of Martian canals, 135-137; connection of comets and meteors, 214, 224

Schmidt, lunar map, 114; observation of comet 1882 (iii.), 217, 218; observes Nova Cygni, 253

Schröter, observations of Venus, 94; lunar mountains, 118; rills, 118; lunar atmosphere, 126

Schwabe, discovery of sun-spot period, 61, 62

See, Dr., duration of sun's light and heat, 80

Serenitatis, Mare, serpentine ridge on, 110, 111; crossed by ray from Tycho, 120

Shackleton photographs spectrum of reversing layer, 75

Sidereal month, 103

Siderites and siderolites, 227

Sinus Iridum, 117

Sirius, companion of, discovered, 8; brightness, 234; colour, 235; brilliancy compared with Venus, 90; with Jupiter, 156

Sirsalis cleft, 119

Smyth, Admiral, on amateur observers, 18, 19, 45

Sodium in chromosphere, 73

Solar system, translation of, 269-272

South, Sir James, 12-inch telescope, 6

Spectroscope, 73, 76

Spectroscopic observations of rotation of Venus, 96; of Martian atmosphere, 140; investigations of Saturn's rings, 180; of Uranus, 195

Spectrum of reversing layer, 75; of chromosphere, 73

Spencer, Herbert, relation of stars and nebulæ, 267

Spica Virginis, 234

Stars, distance of, 231; number of, 232, 233; magnitudes, 234; numbers in different magnitudes, 235; colours, 235-237; change of colour in, 236, 237; constellations, 237, 238; double, 240; multiple, 243; binary, 244; spectroscopic binaries, 245-248; variable, 248-251; new or temporary, 251-255; constitution of, 268

Struve, F. G. W., 'Mensuræ Micrometricæ,' 278

Struve (Otto) discovers satellite of Uranus, 196; verifies discovery of Neptune's satellite, 201

Sun, size, distance, 47, 48; rotation period of, 57-59; methods of observing, 65-67; atmosphere of, 75; light and heat of, 78

Sun-spots, 49, 50; rapid changes in, 54, 55; period of, 62; zones and variation of latitude of, 62

Synodic period, 103

Syrtis Major, 145

Swift, Dean, satellites of Mars, 142

Swift's comet, 214, 224

Taygeta, 256

Telescope, invention of, 1, 2; refracting, 3; achromatic, 5; reflecting, 10, 11; forms of reflecting, Newtonian, Gregorian, Herschelian, Cassegrain, 10, 11; mirrors of reflecting, 11, 12; finders, 23, 24; mountings of, Altazimuth, 25-28; equatorial, 30, 31; house for, 37, 38; management of, 39, 40; powers of, 40, 41

Tempel's comet, 211

Terminator of moon, 107; of Venus, 94

Titius, discovery of Bode's law, 148

Turner discovers Nova Geminorum, 255

Tycho, 114; ray-system of, 108, 120, 121; Brahé observes Nova Cassiopeiæ, 252

Uranus, 190; distance from sun, period, diameter, visibility, 194; spectrum and density, 195; satellites, 196

Ursæ Majoris , duplicity of, 240; binary, 244; spectroscopic binary, 247

Variable stars, 248-251

Variation in sun-spot latitude, 62

Vega, 234; colour of, 235; apex of solar path, 271

Venus, diameter, 89; orbit and elongations, 89; visibility of, 89, 90; brilliancy, 90; reflective power, 90; phases, 92; as telescopic object, 93; atmosphere, 93; blunting of south horn, 94; rotation period, 96; 'phosphorescence' of dark side, 97; question of satellite of, 97, 98; transits, 98; opportunities for observation, 98, 99

Vesta, discovery of 149; diameter of, 152; reflective power, 152

Vienna, 27-inch refractor, 8

Vogel, atmosphere of Mars, 140; discovery of spectroscopic binaries, 245, 246

Washington, 26-inch refractor, 8

Watson, asteroid discoveries, 151, 153

Webb, Rev. J. W., remarks on telescope, 17; on amateurs, 18; on cleaning of eye pieces, 20; visibility of Saturn's rings, 181; lunar chart, 124; 'Celestial Objects,' 124; colouring of Jupiter, 158; description of planetary nebula in Draco, 267

Williams, A. Stanley, seasonal variations in colour of Jupiter's belts, 159; periods of rotation (Jupiter), 163; rotation of Saturn, 174

Wells's comet, 213

Wilson, theory of sun-spots, 60, 61

Winnecke's comet, 211

Wolf, asteroid discoveries, 151

Yerkes observatory, 40-inch refractor, 8, 9; 5-foot reflector, 12

Young, illustrations from 'The Sun,' 48; electric influence of sun on earth, 63; observations of prominences, 74; of reversing layer, 74

Zöllner, reflective power of Jupiter, 156

THE END

BILLING AND SONS, LTD., PRINTERS, GUILDFORD.

Transcriber's Note

- - indicates italic print; = = indicates bold print; + + indicates Old English font; ^ or ^{} indicates a superscript. ° indicates hours (or degrees); ′ indicates minutes (prime = minutes = feet); ″ indicates seconds (double prime = seconds = inches).

Sundry missing or damaged punctuation has been repaired.

Illustrations (or Plates) which interrupted paragraphs have been moved to more convenient positions between paragraphs.

A few words appear in both hyphenatd and unhyphenated versions. A couple have been corrected, for consistency; the others have been retained.

Page x: 'XI' corrected to 'IX'

"IX. THE ASTEROIDS 148"

Page 4: Corrected 'lengthwas' to 'length was'.

"... with a glass whose focal length was 212-1/4 feet."

Page 25: 'familar' corrected to 'familiar'.

"... or, to use more familiar terms,..."

Page 90: "... more especially if the object casting the shadow have a sharply defined edge,..."

'have' is correct, and has been retained (subjunctive after 'if').

Page 92: 'firstfruits' corrected to 'first-fruits'. (OED, and matches 2 other occurrences.)

"The actual proof of the existence of these phases was one of the first-fruits which Galileo gathered by means of his newly invented telescope."

Page 109: 'eyeryone' corrected to 'everyone'.

"... --'the man in the moon'--with which everyone is familiar."

Page 118: 'of' added - missing at page-turn.

"They embrace some of the loftiest lunar peaks reaching...."

Page 128: 'lnnar' corrected to 'lunar'.

"The lunar night would be lit by our own earth,..."

Page 157: 'imch' corrected to 'inch'.

"[Illustration: FIG. 25.

JUPITER, October 9, 1891, 9.30 p.m.; 3-7/8-inch, power 120.]"

Page 158: 'eyepiece' corrected to 'eye-piece', to match all the rest.

"... and a single lens eye-piece giving a power of 36."

Page 205: removed extraneous 'of'.

"The nucleus is the only part of a comet's structure"

Page 209: 'unconsidreed' corrected to 'unconsidered'.

"... that some unconsidered little patch of haze...."

Page 240: 'Ursae' corrected to 'Ursæ' to match entries in the Index, and for consistency.

"... though Riccioli detected the duplicity of Zeta Ursæ Majoris (Mizar), in 1650,..."

Page 248: 'in once and a half times,'. 'once' is as printed (and may have been intended). As it is part of a quote, it has been retained.

"'Once in eleven months,' writes Miss Clerke, 'the star mounts up in about 125 days from below the ninth to near the third, or even to the second magnitude; then, after a pause of two or three weeks, drops again to its former low level in once and a half times, on an average, the duration of its rise.'"

Page 256: Page 256: 'Celæno' appears here in the text; 'Celaeno, 256' is the Index entry. Both are as printed.

Page 281: '285·9″' corrected to '285·9°'

"EQUULEUS.

This follows the pattern of preceding

DRACO.

Page 282: '3·80°' corrected to '3·80″' to match pattern.

"[Sigma] 2161 or : 17 h. 20 m. + 37° 14′ : 4-5·1 : 314·4° : 3·80″. 'Gem of a beautiful coronet' (Webb)."

Page 288: 'Lyrae' corrected to 'Lyræ'.

"Lyræ [epsilon], double double, 241, 242;"

Page 291: 'obsering' corrected to 'observing'.

"methods of observing, 65-67;"

Page 292: 'elongagations' corrected to 'elongations'.

"orbit and elongations, 89;"

Page 292: 'GUIDFORD' corrected to 'GUILDFORD'.

"BILLING AND SONS, LTD., PRINTERS, GUILDFORD."