Chapter VII: The Construction of the Heavens (2)

Aldebaran, 403, 404, 407, 415, 421, 423, 427

Algol, 407, 415, 453, 457, 469–474

Almagest, 4, 6

Al-Mamûm’s school of astronomy at Baghdad, 5

Alphard, 409, 415

Alphonsine tables, 6

Al-Sûfi, description of the stars, 5;
Alphard, red, 415;
Algol, red, 472

Altair, 404, 427

Altazimuth, 184, 202

Altitude, 65

Amplitude, 66

Anderson, Dr., discovery of new star, 489

Andromeda nebula, 409, 529–532

Andromedæ, Gamma, 412, 417

— Nova, 489, 491

Andromede meteor-showers, 393, 394

Angelot, lunar volcanic action, 293

Annular eclipse, 113

— nebulæ, 526, 527

Antares, 404, 415

Anthelmus, new star, 484

Antlia, 468

Aphelion, 75

Apogee, 89

Apse Line, 75

Aquilæ, Eta, 467

Arago, nature of meteorites, 392;
parallax of 61 Cygni, 422

Arc of meridian, 130

Arcturus, 403, 405, 406, 415, 423, 427

Argelander, solar translation, 28;
survey of the heavens, 38;
comet of 1811, 357;
estimate of stars of ninth magnitude, 541

Argo Nebula, 522, 523, 549

— Eta, 462–464

Argon, not a solar element, 250;
peculiar qualities, 255;
found in meteorites, 389

Aries, first point of, 67

Aristarchus, heliocentric system, 4

Aristotle, description of a comet, 358

Asteroids, position in solar system, 229, 230, 310;
discoveries, 311, 314;
diameters, 312, 315;
computation of orbits, 314;
numbers and joint mass, 315;
distribution, 316;
groups, 317;
origin, 318

Asterope, 498, 499

Astronomy, Greek, 3, 4;
Arab, 4–6;
Tartar, 5;
of the Invisible, 31;
gravitational, 11, 33;
spectroscopic, 33–36;
photographic, 36–38

Astrophysics, foundation of, 36

Atmosphere, of the sun, 240, 271;
of Mercury, 277;
of Venus, 278, 279;
of the earth, 286, 313;
of the moon, 294, 313;
of Mars, 299, 307;
of Vesta, 312–313;
presence dependant upon mass, 313;
of Jupiter, 326;
of Uranus, 345

Atmospheric refraction, 52

Augmentation of moon’s diameter, 144

Aurigæ Beta, 404, 454, 456, 457

— New Star, 489

Auroræ, magnetic relations, 17, 288

Auwers’ reduction of Bradley’s observations, 19;
proper motion of Sirius, 437

Azimuth, 65

B

Babinet, rarity of cometary matter, 366

Baden-Powell, Sir George, eclipse-expedition, 259;
coronal photographs, 271

Bailey, Prof., 441, 464, 511, 513, 539

Ball, Sir Robert, 422, 433

Barnard, Prof., photograph of corona of January 1, 1889, 268–9;
effect of totality, 270;
zodiacal counterglow, 272;
photograph of eclipsed moon, 296;
drawing of Mars, 302;
seas of Mars, 306;
measurements of asteroids, 312;
markings on Jupiter’s satellites, 330;
discovery of fifth satellite, 331;
measures of Saturn, 335;
of ring-system, 330;
disappearance of rings, 337;
eclipse of Japetus, 338;
compression of Uranus, 343, 344;
Encke’s comet, 366;
comet-photographs, 378–381;
Swift’s comet, 383;
Nova in Auriga, 494;
Alcyone, 500;
curved nebulosity stretching over constellation of Orion, 520;
annular nebulæ, 526;
stars in streams, 551;
vacancies in the Milky Way, 554

Base line, 131

Baxendell, 484

Bayer, 404, 529

Behrmann, 400, 433, 541

Bellatrix, 408

Bélopolsky, spectrographic determination of Jupiter’s rotation, 325;
absolute velocity of 61 Cygni, 427;
spectroscopic examination of Castor, 451;
observation of Delta Cephei, 456;
Beta Lyræ, 466–467

Berberich, variability of Encke’s comet, 360

Berson, aeronautic ascent, 286

Bessel, _Fundamenta Astronomiæ_, 19;
astronomy of the invisible, 31, 32;
measurement of the Pleiades, 37;
Halley’s comet, 355;
comet of 1807, 362;
Epsilon Lyræ, 411

Betelgeuse, 404, 408, 415, 427

Bianchi, 459

Bianchini, rotation of Venus, 280

Biela, discovery of a comet, 365

Bigelow, theory of Zodiacal Light, 272

Binary stars, 431

Biot, meteoric fall, 387

Bird, quadrants, 19, 20

“Bird, Red,” 415

Birmingham, 417, 485, 486

“Blaze Star,” 485, 487

Bliss, astronomer-royal, 19

Bode’s law, 145, 232, 311, 317, 349

Boeddicker, Dr., heat-phases of eclipsed moon, 295

Bolometer, 226, 239

Bompas, 430

Bond, W. C., discoveries of Hyperion and of Saturn’s dusky ring, 25,
336, 341;
celestial photography, 36, 37;
the great nebula, 530

Bradley, discoveries of aberration and nutation, 18, 20;
reduction of his observations, 19;
Saturn’s rings, 337;
the distance of stars, 419–420;
Gamma Virginis, 445–446

Brahé, Tycho, the moon’s variation, 5;
career, 8;
scheme of the celestial movements, 9

Bredichin, theory of comets’ tails, 369, 370.
(_See also_ Tycho.)

Brenner, ashen light of Venus, 279;
rotation of Venus, 280

Brightest stars, 403, 404, 546

Brinkley, 422

British catalogue, 15, 16

Brooks’ cometary discoveries, 365, 371, 380

Bunsen, foundation of spectrum analysis, 33

Burnham, 433, 437, 441, 448, 509

C

Calcium, represented in Fraunhofer spectrum, 230;
in chromospheric and prominence-spectra, 258, 261, 262

Calendar, 86

Callandreau, capture of comets, 372

Campbell, Prof., spectrum of Mars, 306;
mountains on, 307

Canals of Mars, 301–305

Cancri, S., 474

— Zeta, 439, 440

Canis Majoris, R, 473

Canopus, 403

Capella, 403, 406, 415, 427

Capricornus, 411

Capture-theory of comets, 372

Carbon in sun, 242, 250;
in comets, 368;
in meteorites, 389

Cardinal points, 51

Carrington, sun-spot zones, 247;
sun’s rotation, 248, 249

Casey, 433

Cassegrain telescope, 180

Cassini, rotation of Venus, 280;
red spot on Jupiter, 323;
division of Saturn’s rings, 336;
discoveries of Saturnian satellites, 341

Cassiopeia, Chair of, 405, 481, 549

Cassiopeiæ, Eta, 413, 450

Castor, 404, 406, 413, 450, 451

Catalogues of stars, 70

Celoria, 433, 442, 540

Centauri, Alpha, 410, 413, 422, 440, 441

— Omega, 512, 513, 516, 539

— R, 478

Cephii Delta, 417, 456, 466

— U, 474

Ceraski, luminous night-clouds, 286;
discovery of U Cephei, 474

Ceres, discovery, 311;
diameter, 312

Cerulli, rotation of Venus, 280

Ceti, Mira, 458

Challis, search for Neptune, 32

Chandler, 462, 472, 476

Charlois, asteroidal discoveries, 314

Chemistry, universal, 35, 36;
solar, 250, 255;
of prominences, 256;
of chromosphere, 258;
of comets, 368, 370, 384;
of meteorites, 389

Chromosphere, 253, 258

Chronograph, 175

Chronometer, 175

Circle, meridian, 198;
transit, 198;
position, 208

Circumpolar stars, 46

Clairaut, verification of Newton’s law, 11;
calculation of Halley’s comet, 16

Clark, Alvan, great refractors, 26

— — G., detection of the companion of Sirius, 26, 437

Clarke, dimensions of earth, 134

Clausen, groups of comets, 361

Clerke, Agnes, appearance of R Sculptoris, 416;
examination of Pickering’s catalogue of stars, 541;
estimate of total light of stars to magnitude 9½, 543

Clock, astronomical, 174;
driving, 186;
sidereal, 68

Clock stars, 82

Clusters, globular, 507–517;
irregular, 497–507

“Coal sacks” in Milky Way, 554

Coelostat, 194

Collimation of transit instrument, 200

Collimator of spectroscope, 215

Colours of double stars, 417

Comæ Berenices, 434, 502, 549

Comet, Aristotle’s, 352, 353;
of 1743, 354;
Newton’s, 355;
of 1843, 358, 359;
Tebbutt’s, 362, 368;
Donati’s, 362, 369;
Lexell’s, 365, 370, 371;
Brooks’, of 1889, 365;
of 1893, 380;
Winnecke’s, 368, 371, 372;
Brorsen’s, 370;
Tuttle’s, 372, 393;
Wolf’s, 377;
Rordame’s, 383;
Gale’s, 383;
Leonid, 393, 395

— Halley’s, return in 1759, 16, 17;
status in solar system, 230, 232;
return in 1835, 335, 336;
type of tail, 369;
a client of Neptune, 371, 372

— Encke’s, disturbed by Mercury, 273;
rarefaction, 366;
acceleration, 307;
exempt from Jupiter’s influence, 371

— of 1811, structure, 356, 357;
type of tail, 369;
bulk, 383

— of 1843, surprising appearance, 358;
conditions of movement, 359

— of 1882, photographs, 38, 361;
transit, 359, 361;
period, 300;
spectrum, 369

Comet, Biela’s, discovery, 365;
duplication, 366;
related meteor-swarm, 393, 394

— Wells, spectrum, 368

— photographically detected, 377

Comets, orbits of, 108;
periodic, 109;
domiciled in solar system, 230, 371, 372;
granular nuclei, 353, 379, 384;
tenuity, 354, 384;
classification by Olbers, 358, 383;
groups, 359, 361, 362;
disruption, 360, 366, 379;
photographs, 361, 377, 380;
chemistry, 368, 370, 385;
luminous by electricity, 309, 384;
lost, 370;
short-period, 370, 371;
capture by planets, 371, 372, 384;
share sun’s translation, 372;
meteoric relationships, 384, 393, 394

— tails, multiple, 354, 355, 361, 377;
electrical theory, 357, 369, 383;
passage of the earth through, 302, 365;
three types, 369;
structure shown in photographs, 377, 383

Common, Dr., 25, 510, 520, 532, 534

Conjunctions, 99, 103

Constant of aberration, 59

Constellations, 45

Contacts in eclipse, 114

Copeland, Dr., cometary spectra, 368;
Nova in Auriga, 490;
helium, 519

Copernicus, residence in Italy, 7;
theory of planetary revolutions, 8, 9, 418

Cornelius, Gamma, 479

Corona Borealis, Eta, 437

— — Gamma, 442

— solar, 253;
compound nature of light, 202;
daylight photography, 267;
periodicity of type, 208, 270, 272;
photographs, 268–271;
rarefaction, 271, 361;
connexion with Zodiacal Light, 272, 273

Coronium, 238, 262

Co-tidal lines, 165

Coudé telescope, 27, 296

Crateris, R, 478

Craters, lunar, 292, 307

Crema meteorite, 386

Cross, Southern, 410, 416, 549

Crosswires, 195, 199, 206

Crucis, Kappa, 506

Cygni Beta, 417

— Chi, 460

— (_34_), 482

— (_61_), 422, 427

— Rho, new star near, 486

— Y, 474

Cygnus, 407

D

D’Alembert, verification of Newton’s Law, 11

D’Arrest, asteroidal orbits, 316;
comet, 371, 372

Darwin, G. H., tidal friction, 236;
origin of the moon, 236, 237;
density of Saturn, 333

Day and night, 52

— apparent solar, 79;
mean solar, 79

Declination, 66

De la Rue, celestial photography, 36, 295

Delphini, Beta, 435

— Gamma, 412

Deneb, 407

Denning, rotation of Saturn, 334;
discovery of a comet, 370;
August meteors, 391;
meteor-radiants, 395, 396

Density of earth, 160

Deslandres, prominence-photography, 261;
photographs of the sun as a bright-line star, 262;
daylight coronal photography, 267;
eclipse of 1893, 270;
rotation of Jupiter, 325

Dewar, atmospheric resistance to meteorites, 388

Dhurmsala meteorite, 389

Diameters, determination of, 141

Diamonds in meteorites, 390

Diffraction grating, 216

Direct movement, 89

— vision spectroscope, 216

Distance of the stars, 417

Doberck, Dr., 441, 442, 447, 450, 451

Dollond, invention of achromatic lenses, 21

Donati, discovery of a comet, 362;
cometary spectrum, 368

Double-slit method of photography, 261

Draconis, Gamma, 419, 420

Draper, Henry, photograph of the moon, 36

Dubjago, 435

Dunér, spectroscopic measurement of the sun’s rotation, 249;
R Hydræ, 462;
Y Cygni, 474;
Z Herculis, 475

E

Earth, shape of, 41, 134;
size of, 42, 134;
rotation of, 47, 48, 283, 284;
revolution of, 57;
orbit of, 59, 72;
varying speed of, 75;
real path of, 77;
shadow of, 110;
mass of, 159;
internal heat, 284, 285;
age, 285;
atmosphere, 286, 289;
magnetic relations, 287, 288

Easton, 532, 548

Eccentricity of ellipse, 74

Eclipse, solar, of 1842, 253;
of 1860, 254;
of 1868, 254;
of 1870, 258;
of 1896, 259, 271;
of 1882, 260, 268;
of 1878, 268;
of 1889, 268, 270;
of 1893, 270

Eclipses, lunar, 111;
partial, 111, 114;
annular, 113;
magnitude of, 113;
total of sun, 113;
duration of solar, 115;
number of in a year, 118;
recurrence of, 119;
of satellites, 121;
varieties of lunar, 295;
of Jupiter’s satellites, 329;
of Saturn’s, 342

Ecliptic, 56

— obliquity of, 61

Electrical theory of photospheric radiance, 242;
of corona, 271, 272;
of comets’ tails, 357, 358, 383;
of cometary luminosity, 369, 384

Electra, 498, 499

Elements of an orbit, 106

Elevating floor, 193

Elger, lunar _maria_, 290

Elkin, Dr., transit of great comet, 359;
meteorograph, 396;
measurements, 421–423, 425, 433, 438

Ellipse, properties of, 73;
eccentricity of, 74;
foci of, 74;
to draw an, 74

Elliptical nebulæ, 529–533

Elongations, 99

Encke, discovery of a comet, 366;
resisting medium, 367

Enoch, Book of, 404

Equation of time, 79

Equator, terrestrial, 50;
celestial, 66

Equatorial coudé, 193

Equatorial telescope, 185

Equinoxes, 55;
precession of, 69, 167, 170

Equulei, Delta, 433

Eridani, (_40_), 444

Espin, 460, 482, 494

Establishment of a port, 165

Ether of space, 546

Euler, lunar theory, 11

Evening star, 100

Evolution, of solar system, 235, 310;
of terrestrial, 236, 237, 283

Eye-pieces, 182

F

Fabricius, 458, 483

Fabry, cometary orbits, 372

Faculæ, associated with sun-spots, 244;
rotation, 249;
photographed, 262

Faye, planetary origin, 235, 350;
water on Mars, 299

Fényi, solar eruptions, 259, 260

Finder of telescope, 187

First Point of Aries, 67

Fixed stars, 45, 423

Flammarion, rotation of Venus, 280;
canals of Mars, 304;
condition of Mars, 309

Flamsteed, first astronomer-royal, 15;
stellar parallax, 18;
Flamsteed’s star, 461

Fleming, Mrs., 460, 465, 489, 494–496

Fletcher, 447

Fomalhaut, 404

Fontana, pseudo-satellite of Venus, 282

Forbes, ultra-Neptunian planets, 231

Foucault’s pendulum, 48–50

Fraunhofer, improvement of telescopes, 21;
solar spectrum mapped by, 34

Fraunhofer lines, 34, 249, 259, 271;
interpreted, 35, 250;
reflected in spectrum of Uranus, 346;
in spectra of comets, 368

Fritsche, 433

Frost, spectrograph of Uranus, 346

Froley, 434

G

Galaxy. _See_ Milky Way

Galileo, telescopic observations, 9;
double-star method of parallaxes, 28, 418

Gaseous nebula, 517

Gemini, star cluster in, 504

Geminorum, Zeta, 468

Gemma, Cornelius, 479

Gemmill, 554

Geocentric positions, 70

Geodesy, 129

Gill, Dr., photographs of comet of 1882, 38, 361;
parallax of Sirius, 421;
parallax and velocity, Lacaille, 424;
Omega Centauri, 513

Glasenapp, 433–434

Gledhill, red spot on Jupiter, 323

Globular clusters, 507

Gnomon, 125

Goodricke, 465, 466, 470

Gould, Dr., photographic measurement of the Pleiades, 37;
planetary photography, 327;
Pi Gruis and R Sculptoris, 416;
Kappa Crucis, 506;
stars in Southern Hemisphere, 541;
belt of stars intersecting the Milky Way, 551

Graduated circles, 171

Grating spectroscope, 216

Gravity, surface, on Mercury, 274;
on Venus, 278;
on the moon, 293;
on Mars, 298;
on Saturn, 335;
on Uranus, 345;
on Neptune, 349

Gravitation, laws of, 153;
universal, 156

Greenwich observations, 15, 19, 20

Groombridge, 424

Grosch, corona of 1867, 268

Grubb, Sir Howard, great refractors, 26

— Thomas, Melbourne reflecting telescope, 24

Guinand, optical glass, 21

Gully, Ludovic, 488

Gylden, 423

Gyroscope, 50

H

Hadley, improvement of reflecting telescopes, 21

Hale, spectrographs of prominences, 261;
calcium light pictures of sun and surroundings, 262;
double-slit method of coronal photography, 267

Hall, Prof. Asaph, discovery of the moons of Mars, 26, 309;
rotation of Saturn, 334

— Chester More, invention of achromatic lenses, 20

— Maxwell, 472

Halley, law of gravitation, 10;
acceleration of the moon, 12;
astronomer-royal, 16;
comet calculated by, 16;
transits of Venus, 17;
discovery of proper motion in stars, 423;
discovery of the star cluster in Hercules, 507

Harding, 548

Hartwig, 488

Harvest moon, 95

Heavens, diurnal motion of, 45

Heis, 400, 401, 541

Heliocentric positions, 70

Heliometer, 209

Helium, a chromospheric element, 255, 258;
extracted from clevite, 255

Helmholtz, maintenance of sun’s heat, 234;
past duration of sunlight, 285

Hencke, asteroidal discoveries, 314

Henderson, 422, 447

Henry’s belts of Uranus, 343

Hepidannus, 479

Herculis, Alpha, 413, 416

— Zeta, 435

— Z, 475

Herschel, Sir John, mathematical analysis at Cambridge, 15;
observations of nebulæ, 23, 31;
Magellanic clouds, 30, 31;
survey of the heavens, 31;
photography of sun-spots, 36;
telescope, 180;
great spot-group in 1837, 244;
cyclonic theory of sun-spots, 252;
Halley’s comet, 355;
comet of 1843, 358;
Biela’s comet, 365;
red stars, 416;
orbit of Gamma Virginis, 446;
Kappa Crucis, 506;
2 Messier, 511–512;
22 Messier, 514;
nebula round Eta Argus, 522–523;
30 Doradus, 524;
the trifid nebula, Sagittarius, 525;
planetary nebula, 528–529;
the Nubecula Major, 534–536;
Milky Way, crossed by zone of large stars, 552;
observations in the Southern Hemisphere, 554

— Sir William, the sun’s translation, 19, 28;
reflecting telescopes, 21–23;
discovery of Uranus, 21, 22;
of binary stars, 28;
comprehensive designs, 27, 29;
nebular theory, 30, 35;
rotation of Jupiter’s satellites, 331;
variability of Japetus, 341;
discovery of Uranian moons, 347;
binary stars, 419, 431;
motion real and apparent, 428;
Zeta Herculis, 435;
Xi Ursæ Majoris, 440;
70 Ophiuchi, 441;
5 Messier, 510

Hevelius, 459, 462, 484

Hind, 433, 474, 482, 484

Hipparchus, construction of a star catalogue, 3;
mathematical standpoint, 4

Holden, Prof., solar rotation, 249;
names of asteroids, 315;
helical nebulæ, 528

Holmes, discovery of a comet, 379

Holwarda, Phocylides, 458

Hooke, law of gravitation, 10;
observations of Greek letter Draconis, 18;
Gamma Arietis, 412;
parallax of Gamma Draconis, 419–420

Horizon, visible, 41;
sensible, 44;
celestial, 44;
rational, 44

Horrebow, satellite of Venus, 282

Hour circle, 186

Howlett, depression of sun-spot umbræ, 251

Huggins, Dr., stellar and nebular spectra, 35;
photographed, 37;
observations of prominences, 255;
daylight coronal photography, 267;
prismatic occultation of a star, 294;
spectrum of Mars, 306;
of Jupiter, 326;
of Uranus, 345;
of Winnecke’s comet, 368;
spectrograph of Tebbutt’s comet, 368;
measurement of motion in the line of sight, 426;
spectroscopic examination of new star, 493;
spectroscopic examination of the “fish-mouth” nebula, 518;
discovery of gaseous spectrum, 528

Humboldt, meteoric shower of 1799, 392;
temporary star of 1572, 479–481

Hussey, cometary forms, 380;
photograph of Rordame’s comet, 383

Huygens, 417, 517

Hyades, 407, 549

Hydræ, R, 462

Hydrogen, ultra-violet spectrum in stars, 37;
a gaseous metal, 250;
a constituent of prominences and chromosphere, 255, 258;
velocity of molecules, 313;
free in atmospheres of Uranus and Neptune, 346, 349;
assumed constituent of comets’ tails, 369, 370

Hypothesis of external galaxies, 546

I

Infinity of Space, 546

J

Jacob, 433, 447

Jacoby, measures of photographs, 37

Janssen, photograph of the sun, 243;
spectroscopic method of prominence-observation, 254;
double-slit method, 261

Japetus, remarkable eclipse, 338;
variability, 341;
plane of orbit, 342

Jesse, luminous night-clouds, 286

Job, Book of, 404

Johnson, 450

Juno, discovery, 311;
diameter and albedo, 312, 316;
a twin of Clotho, 317

Jupiter, long inequality, 12, 17;
disturbance of Halley’s comet, 16;
influence upon asteroidal distribution, 316–318;
mass and figure, 318;
rotation, 318, 325, 326;
density, 319, 326;
reflective power, 320;
belts and streamers, 321, 322, 326;
spots, 323, 325;
photographs, 327;
disturbance of comets, 371

Jupiter’s satellites, Galilean quartette, 9, 327, 328;
transits, 329;
constitution, 330;
fifth satellite, 331, 332

K

Kapteyn, 422, 556, 561–563

Keeler, drawings of Jupiter, 321;
description of markings, 322;
spectroscopic test of the meteoric constitution of Saturn’s rings,
339;
measuring velocities of nebula in line of sight, 428;
spectra of the Orion nebula, 519–520

Kelvin, Lord, subterranean temperature, 285

Kepler’s Laws, 10, 155, 339, 417

Kirch, 460, 470, 510

Kirchhoff, spectrum analysis, 33;
Fraunhofer’s lines, 34

Kirkwood, distribution of asteroids, 316, 317;
divisions in Saturn’s rings, 338

Kleiber, number of shooting stars, 390

Koch, 461

Kreutz, relations of great southern comets, 360

Krüger, 442

L

Lacaille, southern nebulæ, 30

Lagrange, verified principle of gravitation, 11;
stability of solar system, 13

Lajoye, 488

Lamp, fate of Brorsen’s comet, 370

Lane’s law, 242

Langley, solar radiation, 238, 239;
spectroscopic effects of sun’s rotation, 249;
temperature of the moon, 294;
fireball, 386

Laplace, verified Newton’s law, 11;
lunar acceleration, 12;
_Mécanique Céleste_, 13, 14;
nebular hypothesis, 235

Lassell, large reflectors, 24;
discoveries of Hyperion, Ariel, and Umbriel, 24, 341, 347;
Saturn’s dark ring, 336

Latitude, terrestrial, 50, 125;
celestial, 68;
of sun, 77;
geocentric, 135;
geographical, 135;
astronomical, 136;
variation of, 136

Leland, Miss, 511

Leonid meteors, 391–395

Leonis, Gamma, 413

— R, 461

Lepaute, Madame, computation of Halley’s comet, 16

Leverrier, discovery of Neptune, 32;
intra-Mercurian planet, 232;
mass of asteroids, 315;
orbit of November meteors, 395

Lewis, 426

Libræ, Delta, 473

Librations, of Mercury, 277;
of Venus, 281;
of the moon, 93, 289

Lick observatory, 25, 26

Light-equation, 329

“Light journey,” 420

Limited number of visible stars, 538, 545

Limiting apertures, 212

Lippershey, inventor of the telescope, 9

Lockyer, spectroscopic observations at the sun’s limb, 254;
classification of prominences, 250;
solar tornadoes, 259

Loewy, Coudé telescope, 27;
lunar photography, 296

Longitude, terrestrial, 50, 125;
celestial, 68

Lowell, rotation of Mercury, 277;
observations of Venus, 279, 281;
lakes of Mars, 301, 302;
relation to canals, 302–304

Luminous night-clouds, 286

Lunar distances, 129

— ecliptic limit, 112

Lyncis (_12_), 450

Lyra, annular nebula in, 526

Lyræ, Beta, 465

Lyraid meteors, 393, 395

M

Maclear, 464

Mädler, search for Martian moons, 309;
compression of Uranus, 343

Madrid meteorite, 385

Magellanic clouds, 30, 534–537

Magnetism, terrestrial, 287, 288

Magnitude, of eclipses, 113;
of stars, 212

Magnitudes, star, 403, 404

Mann, 433

Maps, 133

Maraldi, 462, 470, 511

Marchand, observations of the Zodiacal Light, 273

Markwick, Col., 547

Mars, phases of, 104;
parallax of, 147;
a superior planet, 297;
seasons, 298, 301, 302;
snow-caps, 299, 303, 306;
land and water, 299–301, 305, 306;
continents, 300, 301;
canals, 301, 304;
duplication, 301, 305;
spectrum, 306;
atmosphere, 307, 313;
mountains, 307;
climate, 308;
moons, 309, 310

Marth, Neptune’s satellite, 350

Mascari, rotation of Venus, 280

Maskelyne, astronomer-royal, 19;
founded _Nautical Almanac_, 20;
star-motions, 28

Mass, defined, 151;
sun, 156;
planets, 157;
moon, 158;
of asteroids, 158;
earth, 159;
satellites, 159

Maunder, 460, 488, 493

Maxwell, Clerk, constitution of Saturn’s rings, 337, 340

Mayer, Tobias, lunar tables, 11;
star-motions, 28

Mazapil meteorite, 396

Measurement, of earth, 42, 129;
of sun’s distance, 146;
of binary stars, 208;
of planets, 208

_Mécanique Céleste_, character, 13, 14

Megrez, 402

Mercury, Copernican theory of movements, 8;
transit of, 101;
phases of, 101;
orbit, 273, 274;
atmosphere, 274, 275;
rotation, 275–277;
as an abode of life, 277;
capture of Encke’s comet, 372

Meridian, 50;
line, 51;
arc of, 130;
circle, 198;
photometer, 214

Merope, 498, 499

Messier (_3_), 509

— (_5_), 510

— (_11_), 506

— (_22_), 514

— (_37_), 505

— (_51_), 533

— (_57_), 526

— (_80_), new star in, 485

— (_92_), 509

— (_99_), 534

— discoveries of nebulæ, 30

Metonic cycle, 92

Meteoric systems, 231, 390, 391;
radiants, 392, 395, 396

Meteorites, falls, 385–387;
legal status, 387;
velocities, 387, 388, 390;
thumb-marks, 388;
chemical composition, 389;
enclosed diamonds, 390

Meteors, Perseid, 391, 393;
Leonid, 391–393;
Andromede, 393–394, 396;
relations to comets, 393, 395

Micrometer, wire, or pillar, 205;
evolution of, 207

Michell, prevision of binary stars, 28

Midnight sun, 63

Milky Way, 402, 430, 555, 557

— — star streams, 9;
disc theory, 29

Minimum deviation, 215

Mira Ceti, 458, 459

Mitchell, 421, 431

Mizar, 402, 411, 455, 457

Molyneux, 419, 420

Montanari, 471

Month, 91

Moon, acceleration, 12;
_contumax sidus_, 16;
observations, 19;
apparent motion of, 87;
orbit of, 88, 94;
phases of, 89;
sidereal period of, 89;
synodic period of, 91;
rotation of, 92;
librations of, 93;
harvest, 95;
high and low, 97;
shadow of, 115;
distance of, 143;
size of, 144;
mass of, 158;
possible disintegration, 233;
origin, 236, 237;
rotation, 289;
cones and craters, 290, 292, 293;
rays and rills, 293;
absence of air and water, 294, 313;
temperature, 294, 295;
eclipses, 295;
photography, 295–297

Morning star, 100

Müller, surface of Mercury, 275;
photometry of asteroids, 312;
albedo of Jupiter, 320;
of Saturn, 334;
of Neptune, 349

Muscæ, R, 468

N

Nadir, 45

Nasir Eddin, planetary tables, 5

Nasmyth, conjunction of Mercury and Venus, 278

Nearest fixed stars, 417

Nebula, Orion, 23, 25, 30

Nebulæ, structure, 23;
spiral, 24;
photographs, 23, 25;
first discoveries, 29, 30;
status, 30, 31;
gaseous nature, 30, 35;
annular, 526, 527;
elliptical, 529, 533;
gaseous, 517–524;
planetary, 527–529;
spiral, 533, 534

Nebular hypothesis, 30, 35, 235, 530

Nebulous stars, 529

Neptune, discovery, 32, 229;
distance from the sun, 232;
dimensions, 349;
compression, 351;
retrograde rotation, 351;
planets as viewed from, 351, 352;
family of comets, 371, 372

Neptune’s satellite, discovery, 24;
plane of revolution, 350;
precessional disturbance, 351

Newall, 25-inch refractor, 26

Newcomb, Prof., past duration of sunlight, 285;
light changes of Ariel, 347;
satellite of Neptune, 351;
the runaway star, 424;
proper motion of Alcyone, 501

New stars, 477–497

Newton, H. A., capture of comets, 372;
meteoric cult, 387;
daily number of shooting stars, 390

— Sir Isaac, law of gravitation, 10, 11;
invention of reflecting telescope, 21;
comet of 1680, 355;
decay of comets, 366

Newtonian telescope, 179

Nichol, Dr., 508

Niesten, rotation of Venus, 280;
mass of asteroids, 315

Nodes, 94

North polar distance, 66

Nova Andromedæ, 488

— Aurigæ, 489

— Cassiopeiæ, 479

— Cygni, 486

— Ophiuchi, 484

— Serpentarii, 483

— Vulpeculæ, 484

Nubecula Major, 534

— Minor, 535

Number of visible stars, 538–544

Nutation, 169

O

Oases of Mars, 302–305

Object-glass, achromatic, 177;
photographic, 195;
photo-telescope, 196

Objective prism, 223

Obliquity of ecliptic, 61

Observatories, 191

— Lick, 189, 190, 202

— Nice, 192

— Yerkes, 189

Occultations, 121

— of stars, by the moon, 294;
by comets, 366

Olbers, discovery of Pallas and Vesta, 311;
origin of asteroids, 311, 316;
electrical theory of comets, 357;
classification, 358, 383;
comet discovered by, 371

Ophiuchi, Nova, 483–485

— (_70_), 441

— U, 473, 476

Opposition, 103, 105

Orbit, of earth, 72, 76;
of moon, 88;
elements of a planetary orbit, 106;
of binary stars, 432

Orion, 406, 408, 417

— great nebula in, 517–521

Orionis, Alpha (Betelgeuse), 404, 408, 415, 427

— Iota, 414

— Sigma, 414

— Theta, 414

“Owl,” nebula, 528

P

P (_34_) Cygni, 482

Palisa, discoveries of asteroids, 314

Palitzsch, 470

Pallas, discovery, 311;
diameter, 312

Parallax of stars, 419, 420

— diurnal, 140;
equatorial horizontal, 140;
horizontal, 140;
of sun, 146;
of Mars, 147

Parmentier, distribution of asteroids, 316

Pegasus, Square of, 409

Pegasi, Kappa, 433

— (_85_), 434

— U, 469

Pendulum observations, 135;
compensated, 174

Penumbra, of earth’s shadow, 111

Percentage of stars in Milky Way, 547, 548

Perigee, 89

Perihelion, 75

Perrotin, rotation of Venus, 280;
of Uranus, 343;
markings on Uranus, 344

Persei, Beta (Algol). _See_ Algol

Perseid meteors, 391;
associated with Tuttle’s comet, 393

Perseus, 407

— star clusters in, 503

Perturbations, 158

Peters, 428

Phases of moon, 89;
of Venus, 101;
of Mars, 104

Phocylides Holwarda, 458

Photographic telescopes, 194

Photography of nebulæ, 23, 25, 38;
of sun-spots, 36, 243, 244;
of the moon, 36, 295–297;
of stellar spectra, 37;
of comets, 38, 354, 377–383;
celestial, 194;
of spectra, 219, 223;
of the eclipsed sun, 254;
of the reversing layer, 259;
of prominence-spectra, 260;
of prominences and faculæ, 261, 262;
of the corona, 267, 269–271;
planetary, 327; meteoric, 396

Photoheliograph, 197

Photometers, wedge, 213;
meridian, 214

Photosphere, visible structure, 242

Piazzi, five-foot circle, 20;
discovery of Ceres, 311

Pickering, Prof. E. C., photometric measures of asteroids, 312;
photograph of Jupiter, 327;
the spectrum of Alpha Centauri, 441;
the spectrum of Pleione, 498

Pickering, W. H., lunar photographs, 296;
mounting of telescopes, 297;
lakes and canals of Mars, 301, 304;
water area on Mars, 305;
star collisions, 495;
nebula surrounding Zeta Orionis, 520

Pigott, 467

“Pilgrim star,” 479–482

Planetary nebulæ, 527–529

Planets, apparent movements of, 98;
interior and exterior, 98;
conjunctions of, 99, 103;
phases of, 101, 104;
oppositions of, 103;
synodic periods of, 107;
times of revolution, 107;
relative distances of, 144;
distances of, 150;
terrestrial, 229;
giant, 229, 319, 343;
trans-Neptunian, 231;
intra-Mercurian, 232;
decay, 233;
comets captured by, 371, 372

— minor. _See_ Asteroids

Pleiades, 404, 407, 497–502, 539, 549

Pleione, 498

“Plough,” 400–402, 405

Plummer, short-period comets, 371;
Encke’s, 372

Podmaniczky, Baroness, 488

Pogson, 485

Polar axis, 185

Polaris. _See_ Pole Star

Pole, celestial, 46; terrestrial, 50;
movements of, 138

Pole Star, 46, 405, 412, 421, 427

Pollux, 404, 406, 415, 427

Pond, defects of Greenwich quadrant, 19;
astronomer-royal, 20

Position, angle, 208;
circle, 208

Poynting’s experiment, 160

Præsepe, 502

Precession, of equinoxes, 69;
effects of, 170;
luni-solar, 169

Prime vertical, 210

Principia, publication, 10, 13;
character, 14

Prism, action of, 215;
objective, 223

Prismatic camera, 223

— spectroscope, 215

Pritchard, Prof., 422, 424

Proctor, Saturn’s rings, 341;
distance of Uranus, 344;
Proctor’s chart, 548;
stars in streams, 550

Procyon, supposed satellite, 31, 32;
order of magnitude, 404;
parallax of Procyon, 421;
Procyon approaching the Earth, 427

Prominences, solar appendages, 253, 254;
spectrum, 254, 256, 258, 260;
daylight observations, 254, 255;
quiescent and eruptive, 256;
periodicity, 257;
rapid development, 259;
spectral photography, 260, 261

“Proper motions” of stars, 423–431

Ptolemaic system, 3, 4, 6

Q

Quadrature, 105

R

Rambaud, absorption in solar atmosphere, 240;
fireball, 380

Ramsay, terrestrial discovery of helium, 255

Ramsden, astronomical circles, 20

Raynard, the sun a nebulous body, 253;
future of Saturn’s ring-system, 340;
outflows from comets, 380;
star streams, 551

Ravené, gravitational disturbance by asteroids, 315

R Centauri, 478

Reading microscope, 172

Recurrence of eclipses, 119

“Red Bird,” 415

Red spot on Jupiter, 323, 324

Red stars, 416

Reduction of observations, 18, 19

Refracting telescope, 176

Refraction, 52

— in Venus, 278

Reflecting telescope, 178

Regression of moon’s nodes, 94

Regulus, 406, 410, 427

Retrogradation, 89, 103

Reversing layer, 249, 258, 271;
photographed, 259

Rich and poor regions, 549

Richaud, 440

Rigel, 404, 414, 427

Right ascension, 66

Roberts, Dr., 23, 107, 502, 503, 508, 511, 520, 525–528, 530, 533, 534,
539, 540

Roberts, A. W., 440, 441, 469

Roche, minimum distance of satellites, 340

Römer, velocity of light, 329

Rosse, Earl of, giant reflector, 24

Roszl, mass of 311 asteroids, 315

Rotation of earth, 47, 48;
of moon, 92

Rowland grating, 217

— solar elements, 250

Russell, photograph of Swift’s comet, 377;
Kappa Crucis, 506;
the “key-hole” nebula, 522;
the Magellanic clouds, 536

Rutherfurd, photographs of the moon, 295

S

Sacrobosco, treatise on the sphere, 6

Sagittarii, Zeta, 434

Saros, 120

Satellites, movements of Satellites, 108;
masses of Satellites, 159

— discoveries, 9, 23, 25, 26, 309, 347;
apportionment, 230;
formation checked by tidal friction, 277, 282;
planes of revolution, 328, 347, 348, 350;
transits, 329, 330, 342;
eclipses, 329, 342;
variability, 330, 341, 347;
rotation, 331, 341, 342, 347

Saturn, density, 333;
spectrum, 334;
rotation, 334, 339;
dimensions, 535

Saturn’s ring-system, dusky member, 25, 336, 338;
dimensions, 336;
constitution, 337, 339, 340;
albedo, 338

Sawyer, U Ophiuchi discovered, 473;
variability of R Canis Majoris detected, 473

Schaeberle, photographs of corona of 1893, 270;
land and water on Mars, 306

Scheiner, spectra of sun-spots, 251

Schiaparelli, rotation of Mercury, 275;
map of Mercury, 277;
rotation of Venus, 280, 281;
canals of Mars, 301;
duplication, 305;
climate of Mars, 308;
compression of Uranus, 343;
comets and meteors, 393;
theory of extinction of light, 544

Schiehallion experiment, 161

Schmidt, map of the moon, 290

Schönfeld, 461, 464, 466, 467, 473, 483

Schorr, 442

Schur, 433, 442

Schuster, photograph of eclipsed sun, 268

Schwabe, discovery of sun-spot periodicity, 245

Seasons, 61

Secchi, observations of prominences, 256;
spectrum of Uranus, 345

See, Dr., 413, 433–435, 440, 442, 447, 448

Seeliger, photometric measures of Saturn’s rings, 339

Serpentarii, Nova, 483

Sextant, 211

Shackleton, photograph of the reversing layer, 259

Ship, position of, 128

“Sickle” in Leo, 406

Siderostat, 194

Sidgreaves, elevations of chromosphere, 258

Sirius, proper motion, 17, 31;
companion, 32;
spectrum, 37;
size, 403;
position, 409;
colour, 414;
distance, 418, 421;
discovery of proper motion, 423;
a binary star, 437;
comparative magnitude, 438

Smyth, 447, 448, 502, 505, 508

Solar, constant, 239

— diagonal, 183

— eclipses, 113

— ecliptic limit, 118

— System, dominated by gravity, 29;
constitution, 229, 232;
dimensions, 231;
stability, 232;
origin, 235, 236

Southern Cross, 410, 416, 549

Shouting, 68, 198

Spectroheliograph, 225

Spectroscope, prismatic, 215;
direct vision, 216;
grating, 216;
Lick star-, 219;
Rowland, 217;
tele-, 219

Spectroscopic measurements of rotation;
the sun, 248;
Venus, 281;
Saturn, 339

Spectrum, solar, 34, 250;
of stars and nebulæ, 35, 37;
measurement of, 218;
sun-spot, 250, 251;
prominence, 254, 256, 261;
chromospheric, 258;
of Mercury, 275;
of Venus, 279;
auroral, 288;
of Jupiter, 326;
of Saturn’s rings, 338;
of Uranus, 345, 346;
of Neptune, 351;
of comets, 368

Spherical excess, 133

Spica, 404, 410

Spiral nebulæ, 533, 534

Spoerer, solar rotation, 249

Star of Bethlehem, 101

Star-charting, photographic, 38

— cluster, 17

— spectroscope, 219

— time, 68

Stars, temporary, 3, 8, 477;
proper motions of, 17, 19, 28, 425, 427;
fixed, 45;
circumpolar, 46;
diurnal motion of, 46;
aberration of, 58;
catalogues of, 71;
clock, 82;
morning and evening, 100;
magnitudes, 403, 404;
Pole, 405, 412;
double, 410;
coloured, 416;
red, 416;
nearest, 417;
binary, 431;
variable, 458

Stationary points, 103

Stone, mass of Titan, 342

Stoney, G. Johnstone, atmospheres of planets, 313

Stratonoff, sun’s rotation from faculæ, 249

Suess, theory of lunar formations, 292

Sun, translation, 28, 229;
apparent movements of, 55, 77;
midnight, 63;
apparent diameter of, 72;
mean, 79;
eclipses of, 113;
distance of, 146;
mass of, 156;
maintenance of heat, 234;
radiative power, 237–239, 241, 242;
temperature, 239, 240;
magnitude, 240, 241;
luminous surface, 242;
spots, 243–249, 251, 252;
periodicity, 246;
rotation, 247–249;
chemistry, 250;
theories, 252

Sun-dial, 78

Sun’s motion in space, 428

Sun-spots, observed by Galileo, 9;
construction, 243, 251;
zones, 245, 247;
periodicity, 245, 247;
irregular movements, 247–249;
spectra, 250–252

Sutton, 553

Swift, Lewis, comet discovered by, 377, 378, 383

Sykora, elevation of spotted areas on the sun, 252

Synodic period, of moon, 91;
of planets, 107

T

Tacchini, spectrum of Venus, 279;
rotation, 280

Talcott’s latitude method, 124

Tauri, Alpha. _See_ Aldebaran

— Lambda, 473

Tebbutt’s comet, 362, 368

Telescope, invention of, 9;
achromatic, 20, 21;
reflecting, 21, 24, 25, 178;
refracting, 20, 25–27, 176;
future improvement, 26, 27, 297;
Newtonian, 179;
Cassegrain, 180, 181;
Herschellian, 180;
Skew Cassegrain, 181;
magnifying power of, 184;
illuminating power of, 184;
altazimuth, 184;
equatorial, 185;
Rosse, 187;
Common, 5-foot, 188;
Lick, 190;
fixed, 194;
photographic, 194

Telespectroscope, 219

Tempel, 501

“Temporary stars,” 477–497

Theodolite, 205

Thiele, 435, 447, 451

Thome, comet of 1887, 360

Tidal evolution, 167

Tidal friction, 166;
in earth-moon system, 236, 283, 284;
on Mercury, 277;
effect on satellite-formation, 278, 282;
on Venus, 282;
on Phobos, 310;
on Saturnian satellites, 342

Tides, 162;
spring and neap, 164;
priming and lagging, 164

Time, apparent, 78;
equation of, 79;
mean solar, 79;
determination of, 82;
at different places, 83;
Greenwich mean, 83;
local, 83;
telegraphy, 84;
zone, 84;
balls, 85

Tisserand, revolutions of Jupiter’s fifth satellite, 331;
disturbance of Neptune’s satellite, 351;
capture of comets, 372

Todd, Miss M. L., drawing of corona, 268

— Prof., trans-Neptunian planet, 231

Toucani (_41_), 513

Transit circle, 198–202

— instrument, 202

— of Venus, 101, 148

Triangulation, 53

Troughton, instrumental improvements, 19, 20

Trouvelot, mountains of Venus, 279;
rotation, 280

Twilight, 53

Tycho Brahé, 5, 8, 9, 405, 418, 479, 481, 529

U

Ulugh Beigh, observations at Samarcand, 5

Umbra of earth’s shadow, 111

Uranus, discovery, 22, 229;
perturbations, 32, 231;
dimensions and markings, 343–345;
analogy with Neptune, 343, 351;
rotation, 344, 348;
spectrum, 345, 346;
satellites, 347, 348;
comets captured by, 371, 395

Ursa Major, stars in, 400, 401

Ursæ Majoris, Xi, 440

V

Variation of latitude, 136

Variable stars, 458

Vega, 403, 406, 414, 422, 427

Venus, phases observed by Galileo, 9;
transits, 17;
phases of, 101;
transit of, 101, 148;
atmosphere, 278, 281, 282;
ashen light, 279;
spectrum, 279;
rotation, 280, 281;
imaginary satellite, 282

Vernier, 172

Very, distribution of lunar heat, 295

Vesta, discovery, 311;
diameter and brightness, 312;
mass, 313

Villarceau, 433

Virginis, Alpha (Spica), 404, 410

— Gamma, 413, 444–450

— Tau, 456

— W, 469

Visible stars, number of, 538–546

Vogel, spectrum of Jupiter, 326;
of Uranus, 345;
binary or multiple system of Beta Lyræ, 466;
diameter of Algol, 472

Volcanic action, terrestrial, 284;
lunar, 290, 292

Von Gothard, 465

Vulpeculæ, Nova, 484

— S, 484

W

Ward, 488

Way, Milky, 402, 430, 549, 557

Webb, 528

Wedge, photometer, 213

Weight, defined, 151;
of the earth, 160

Wells’ comet, 368

Williams, A. Stanley, rotation of Venus, 280;
of Jupiter, 325;
photographs of Jupiter, 327;
spots on Saturn, 334

Wilson, Alexander, depression of sun-spots, 251

— W. E., temperature of the sun, 240

Winnecke, 422

Winnecke’s comet, 368, 371, 372

Wire micrometer, 205

Wolf, Max, photographic discovery of asteroids, 314;
comet discovered by, 377;
chart of the Pleiades, 499

Wrublewsky, 434

Y

Year, 85;
sidereal, 85;
tropical, 85;
leap, 86

Yendell, 474

Yerkes, 40-inch refractor, 26, 27

Young, solar eruption, 256;
spectrum of chromosphere, 258;
reversing layer, 258;
spectrum of Venus, 279;
brightness of Phobos, 309;
belts of Uranus, 343;
size of Uranus, 345;
the sun and planets, seen from Neptune, 349, 352;
Andromede meteors, 394

Z

Zenith, 45

— telescope, 210

Zodiac, 60

Zodiacal Light, 272, 273

Zöllner, albedo of Mars, 298, 334;
of Jupiter, 320;
of Neptune, 349;
estimate of sunlight, 543

Zone time, 84

THE END.

-----

Footnote 1:

There is a very complete paper on “How to find Easter,” by Dr.
Downing, in the _Journal_ of the British Astronomical Association,
vol. ii., p. 264.

Footnote 2:

The application of Kepler’s third law gives us P = _a_^{³⁄₂} years,
but as this is not strictly true, both P and _a_ must be given where
the greatest possible accuracy is desired.

Footnote 3:

The diagram is based upon one given by Prof. Albrech in the
_Astronomische Nachrichten_, No. 3333. The dotted part of the curve
could not be directly derived on account of insufficient observations.

Footnote 4:

The focal length of a lens is the distance from its centre at which an
image of a very distant object, such as the sun, is formed.

Footnote 5:

In a British inch there are 25·4 millimetres.

Footnote 6:

Proctor: “Old and New Astronomy,” p. 327.

Footnote 7:

Langley: “The New Astronomy,” p. 108.

Footnote 8:

The “bolometer,” invented by Langley, measures heat with exquisite
refinement by means of its electrical effects.

Footnote 9:

W. E. Wilson: _Monthly Notices_, vol. lv., p. 457.

Footnote 10:

_Observatory_, vol. xviii., p. 344.

Footnote 11:

Frost-Scheiner: “Astronomical Spectroscopy,” p. 177.

Footnote 12:

_Astronomische Nachrichten_, No. 3330.

Footnote 13:

_Knowledge_, vol. vi., p. 13.

Footnote 14:

“The Sun,” p. 206, first edition.

Footnote 15:

“Memoirs of the Royal Astronomical Society,” vol. xli., p. 435.

Footnote 16:

_Astronomy and Astro-Physics_, vol. xiii., p. 122.

Footnote 17:

_Comptes Rendus_, December 26, 1893.

Footnote 18:

_Knowledge_, vol. iv., p. 105.

Footnote 19:

“Rapport de la Mission envoyée an Sénégal,” p. 31.

Footnote 20:

“Harvard Annals,” vol. xix., part ii.; 1893.

Footnote 21:

“The Solar Corona discussed by Spherical Harmonics;” Washington, 1889.

Footnote 22:

_Bulletin Astronomique_, April, 1896.

Footnote 23:

According to G. Müller, _Potsdam Publicationen_, No. 30, p. 369,
Zöllner fixed the albedo of Mercury at 0·13.

Footnote 24:

_Astr. Nach._, No. 3171.

Footnote 25:

_Astr. Nach._, No. 3406.

Footnote 26:

_Ibid._, No. 2944.

Footnote 27:

_Astr. Nach._, No. 3332.

Footnote 28:

This was in principle suggested by Proctor in “The Old and New
Astronomy.”

Footnote 29:

_Nature_, vol. li., p. 227.

Footnote 30:

Kelvin, _Nature_, p. 440; Clarence King, _American Journal of
Science_, January, 1893.

Footnote 31:

_Ciel et Terre_, 16th March, 1895.

Footnote 32:

_Himmel und Erde_, Feb., 1889; _Astr. Nach._, No. 3347; A. Battandier,
_L’Astronomie_, 1894.

Footnote 33:

Balfour Stewart: “Ency. Brit.,” vol. xvi. pp. 164, 165.

Footnote 34:

A. Paulsen: _Ciel et Terre_, 1 Juillet, 1895, p. 202.

Footnote 35:

Elger: “The Moon,” p. 73.

Footnote 36:

“Publications, Astronomical Society of the Pacific,” vol. vii., p.
144.

Footnote 37:

“Harvard Annals,” vol. xxxii., part i., p. 109.

Footnote 38:

_Astronomy and Astro-Physics_, Nov., 1894, p. 718.

Footnote 39:

“Popular Astronomy,” 1895, p. 347.

Footnote 40:

_Astr. Nach._, No. 3271 (Schiaparelli).

Footnote 41:

“Popular Astronomy,” vol. i., p. 348.

Footnote 42:

_Scientific American_, Feb. 29, 1896.

Footnote 43:

Schiaparelli: _Astronomy and Astro-Physics_, Nov., 1894, p. 720.

Footnote 44:

_Astronomy and Astro-Physics_, August, 1894, p. 554.

Footnote 45:

“Publ. Astro. Soc. of the Pacific,” vol. iv., p. 196.

Footnote 46:

_Monthly Notices_, vol. lvi., p. 166.

Footnote 47:

Campbell: “Publ. A. S. P.,” vol. vi., p. 273.

Footnote 48:

_Ibid._, vol. ii., p. 248.

Footnote 49:

_Ibid._, vol. vi., p. 110.

Footnote 50:

_Astronomy and Astro-Physics_, October, 1894, p. 640.

Footnote 51:

_Potsdam Publicationen_, No. 30, 1893.

Footnote 52:

Barnard: _Monthly Notices_, vol. lvi., p. 55.

Footnote 53:

John Hopkins’ _University Circular_, Jan., 1895.

Footnote 54:

_Astr. Nach._, No. 3359.

Footnote 55:

_Monthly Notices_, vol. lvi., p. 250.

Footnote 56:

Barnard: _Astr. Journal_, No. 325, 1894.

Footnote 57:

“Publ. A. S. P.,” vol. ii., p. 286.

Footnote 58:

Maunder: _Knowledge_, vol. xix., p. 5.

Footnote 59:

_Monthly Notices_, vol. lvi., p. 143.

Footnote 60:

“Scientific Proceedings, R. Dublin Society,” vol. viii., p. 398.

Footnote 61:

_Astro.-Phys. Journal_, May, 1896, p. 394; “Rapport de l’Observatoire
de Paris,” 1895, p. 22.

Footnote 62:

Proctor: “Old and New Astronomy,” p. 584.

Footnote 63:

“The subject of slant-markings,” Mr. Stanley Williams remarks (_loc.
cit._), “has only just begun to be investigated.”

Footnote 64:

“Jupiter and his System,” by Ellen M. Clerke, p. 43.

Footnote 65:

_Comptes Rendus_, t. cxix., p. 581.

Footnote 66:

G. H. Darwin: _Harper’s Magazine_, June, 1889.

Footnote 67:

Barnard, _Monthly Notices_, vol. lvi., p. 163.

Footnote 68:

Lewis: _Observatory_, vol. xviii., p. 379.

Footnote 69:

_Monthly Notices_, vol. lii., p. 419.

Footnote 70:

“Abhandlungen Akad. der Wissensch.” München, Bl. xvi., p. 403.

Footnote 71:

_Astro-Physical Journal_, May, June, 1895.

Footnote 72:

“Old and New Astronomy,” p. 640.

Footnote 73:

“Phil. Trans.,” vol. lxxxii., p. 17.

Footnote 74:

“Publications Astr. Soc. of the Pacific,” vol. iii., p. 284.

Footnote 75:

_Astr. Journal_, No. 370.

Footnote 76:

Perrotin: “Vierteljahrsschrift Astr. Ges.,” Jahrg. xxiv., p. 267.

Footnote 77:

“Annales de l’Observatoire de Nice,” t. ii., 1887.

Footnote 78:

Keeler: _Astr. Nach._, No. 2927.

Footnote 79:

Gregory: _Nature_, vol. xl., p. 236.

Footnote 80:

“General Astronomy,” p. 372.

Footnote 81:

_Astronomical Journal_, No. 342.

Footnote 82:

Tisserand: _Astronomy and Astro-Physics_, vol. xiii., p. 291 (1894).

Footnote 83:

_Comptes Rendus_, t. cvii., p. 804.

Footnote 84:

_Astronomical Journal_, No. 186.

Footnote 85:

“General Astronomy,” p. 372.

Footnote 86:

“Observations at the Cape of Good Hope,” p. 396.

Footnote 87:

“Monat. Correspondenz,” Bd. xxv., pp. 3–22, 1812.

Footnote 88:

Fessenden: _Astro-Physical Journal_, vol. iii., p. 40.

Footnote 89:

_Astr. Nach._, No. 2837.

Footnote 90:

Guillemin: “The World of Comets,” p. 282.

Footnote 91:

_Astr. Nach._, No. 2437.

Footnote 92:

_Knowledge_, Feb., 1896, p. 41.

Footnote 93:

For an account of its spectral changes, see Campbell in _Astr. and
Astr.-Physics_, vol. xi., p. 698.

Footnote 94:

Barnard, _Knowledge_, vol. viii., p. 229.

Footnote 95:

Denning: _Astronomy and Astro-Physics_, vol. xii., p. 371.

Footnote 96:

_Astroph. Journal_, Jan., 1896, p. 42.

Footnote 97:

Ranyard: _Knowledge_, vol. ix., p. 159.

Footnote 98:

“Publications Astr. Pac. Society,” vol. vii., p. 166.

Footnote 99:

Hussey: _loc. cit._, p. 171.

Footnote 100:

Holden: “Publ. Astr. Pac. Society,” vol. ii., p. 19. H. A. Newton:
_Ibid._, vol. iii., p. 91.

Footnote 101:

“Report Bri. Ass.,” 1891, p. 805.

Footnote 102:

S. Meunier: “Encycl. Chimique,” t. ii., p. 461.

Footnote 103:

Young: “Gen. Astr.,” p. 435.

Footnote 104:

Cornish: _Knowledge_, vol. vi., p. 163.

Footnote 105:

_Journal Brit. Astr. Ass._, vol. vi., p. 432.

Footnote 106:

H. A. Newton: “Proc. Amer. Phil. Society,” vol. xxxii.

Footnote 107:

Quoted by Sir F. Palgrave: “Phil. Trans.,” vol. cxxx., p. 175.

Footnote 108:

_Observatory_, April, 1895.

Footnote 109:

_Observatory_, Jan., 1896.

Footnote 110:

It has been recently seen again in America.

Footnote 111:

_Journal of the British Astronomical Association_, March, 1891.

Footnote 112:

_Nature_, Feb. 13, 1896.

Footnote 113:

“Planetary and Stellar Studies,” p. 257.

Footnote 114:

See Chapter V.

Footnote 115:

_Comptes Rendus_, March 30, 1896.

Footnote 116:

_Nature_, April 30, 1896.

Footnote 117:

“Cape Observations,” p. 34.

Footnote 118:

_Journal of the British Astronomical Association_, vol. iv., No. 11,
p. 21.

Footnote 119:

_Journal of the British Astronomical Association_, vol. vi., No. 6, p.
312.

Footnote 120:

Recent observations show that the total variation is 2·71
magnitudes—the largest variation known for an Algol star.

Footnote 121:

“Cosmos,” Bohn’s edition, vol. iii., p. 205.

Footnote 122:

It was, however, asserted by Herlicius that he had seen it on Sept.
27.

Footnote 123:

The spectrum, however, seems to have since become continuous.

Footnote 124:

_Astronomical Journal_, No. 100.

Footnote 125:

_Journal of the British Astronomical Association_, March, 1892.

Footnote 126:

_Journal of the British Astronomical Association_, February, 1895,
vol. v. No. 4.

Footnote 127:

_Ibid._, April, 1895, p. 328.

Footnote 128:

_Journal of the British Astronomical Association_, February, 1892.

Footnote 129:

_The Observatory_, December, 1895.

Footnote 130:

“Planetary and Stellar Studies,” p. 188.

Footnote 131:

_Nature_, September 6, 1894.

Footnote 132:

_Nature_, June 4, 1896.

Footnote 133:

“Cosmos,” vol. iii., Bohn’s edition, p. 192.

Footnote 134:

Humboldt’s “Cosmos,” Bohn’s edition, vol. iv., pp. 327, 328.

Footnote 135:

_Monthly Notices_, Royal Astronomical Society, June, 1888.

Footnote 136:

“Old and New Astronomy,” p. 794.

Footnote 137:

_Nature_, June 4, 1896.

Footnote 138:

_Nature_, September, 1894.

Footnote 139:

_Ibid._, October 4, 1894.

Footnote 140:

“Outlines of Astronomy,” tenth edition, p. 657.

Footnote 141:

_Nature_, November, 21, 1895.

Footnote 142:

_Nature_, January 16, 1896.

Footnote 143:

_Nature_, August 9, 1888.

Footnote 144:

Humboldt’s “Cosmos,” Bohn’s edition, vol, iii., p. 143.

Footnote 145:

See _Knowledge_, June, 1895.

Footnote 146:

“The Universe and the Coming Transits,” p. 200.

Footnote 147:

_Journal of the British Astronomical Association_, May, 1895, p. 383.

Footnote 148:

_Knowledge_, May, 1896.

Footnote 149:

_Knowledge_, July, 1891.

Footnote 150:

_Knowledge_, January, 1894, p. 17.

Footnote 151:

_Journal of the British Astronomical Association_, April, 1895, p.
304.

Footnote 152:

The Italics are Herschel’s.

Footnote 153:

A full discussion of Struve’s views will be found in Chapter XVI. of
“The Visible Universe,” by the present writer.

Footnote 154:

“The Meteoritic Theory,” pp. 380, 381.

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