Soret, solar temperature,218
South, observations of double stars,45;12-inch lens,113Rosse reflector,117occultation by Mars,276
Spectroscopic binaries,387-391
Spectrum analysis, defined,130;first experiments,131132applied to the sun,133-135156to the stars,133372373Kirchhoff's theorem,135elementary principles,139140effects on science,141142radial motion determined by,201386investigations of comets by,342343of new stars,393399of nebulæ,401-403
Spencer, position of nebulæ,422
Spitaler, attendants on Brooks's comet,366
Spitta, transits of Jupiter's satellites,292
Spörer, solar rotation,148149;chromosphere,199200
Stannyan, early notice of chromosphere,68
Star catalogues,28,31,32,60,414415;spectroscopic,381385386photographic,412-414photometric,420421
Star-drift,426
Star-gauging,13,19,47
Star-maps,77,78,81,284413415;photographic,413414
Stars, movements, 9,10,35,39,415426;radial,386387406comparative brightness,13,49,50,420421distances, 35-37,416-418chemistry,372381382spectroscopic orders,373colours,374development,375-377actual magnitudes,422gregarious,426
Stars, double, physical connection surmised,17;proved,18,442masses,38,42catalogues,43,45,47,50,418419orbits,46,418discoveries,43,46,47,418419435photographs,409evolution,420
Stars, gaseous,377-380
Stars, temporary,24,392-401
Stars, variable, early discoveries,9;η Carinæ,48,49,379sun-spot analogy,128392spectra,379Algol class,390391catalogues,391392
Stefan, law of cooling,219
Steinheil, stellar photometry,420;silvered glass reflectors,429
Stewart, Balfour, Kirchhoff's principle, 135note;solar investigations,154155
Stewart, Matthew, solar distance by lunar theory,230
Stokes, prevision of spectrum analysis,138
Stone, E. J., reversal of Fraunhofer spectrum,172;distance of the sun,231232236transit of Venus,240Cape catalogue,415proper motions,426
Stone, O., star catalogues,415;measures of double stars,419
Stoney, carbon in photosphere,152;dynamical theory of planetary atmospheres,288perturbations of Leonids,338status of red stars,375
Stratonoff, star counts in Pleiades,411
Stroobant, satellite of Venus,256
Struve, F. G. W., stellar parallax,35;career and investigations,43-45occultation by Halley's comet,106Russo-Scandinavian arc,261262
Struve, Ludwig, solar translation,40
Struve, Otto, parallax of η Cassiopeiæ,38;solar velocity,40his father's successor at Pulkowa,45eclipse of 184262,64Neptune's satellite,84research on Saturn's rings,300301variable nebula,403
Stumpe, solar translation,40
Sun, Herschel's theory, 54-57,70,149;atmospheric circulation,58,59chemical composition,135211-213mode of rotation,146147Kirchhoff's theory,149Faye's,150-152convection currents in,150152165dissociation,152206-210luminous outbursts,159-161explosions,205heat emission,216217221222225226temperature,217-220226problem of distance,227results from transits,230232236240from oppositions of Mars,231237from light-velocity,232241from measurements of minor planets,238concluded value,242maintenance of heat supply,310-313past and future duration,312
Sun-spots, speculations regarding,52,53;Wilson's demonstration,53,154distribution,53,58,148cyclonic aspect,58,144157158periodicity,126128162163magnetic relations,127160161meteorological,129164auroral,129130160162photographs,145154level,155spectra,156207208volcanic hypothesis,158Lockyer's rationale,159planetary influence,163relation to Jovian markings,297[Pg 487]relation to Jovian markings,297Swan, chromosphere,70;sodium line,132
Swift, E., discovery of a comet,368
Swift, L., fallacious glimpse of Vulcan,181250;discovery of a comet,368
Tacchini, eclipse of 1883181;white prominences,184prominences and chromosphere,199200spectrum of Venus,254
Talbot, Fox, spectrum analysis,131;spectroscopic method of determining stellar orbits,387
Tarde, nature of sun-spots,52
Taylor, eclipse expedition,187;spectrum of Uranus,305achromatic lenses,431
Tebbutt, comets discovered by,326352;comet of 1882359
Telescopes, achromatic,112431432
Telescopes, equatoreal,84,120121
Telescopes, reflecting, Short's,4,109115121;Herschel's,12,109-111Lassell's,83,114121varieties of construction,109110Rosse's,115-119434Common's,407412429
Telescopes, refracting, Fraunhofer's,34,35,121;Clark's,114429430433436Grubb's,430433with bent and horizontal mountings,436-438
Tempel, red spot on Jupiter,294;comet discoveries,327cometary observations,352362Andromeda nebula,394discovery of Merope nebula,410
Temperature, of the sun,217-220226;of the moon,269270of space,270on Mars,277
Tennant, eclipse observations,168169174
Terby, surface of Mars,278279281;secondary tail of comet,355
Thalén, basic lines,207;map of solar spectrum,210solar elements,212
Thollon, line-displacements by motion,202364;atlas of solar spectrum,211440lunar atmospheric absorption,264
Thome, comet discovered by,361
Thomson, Sir William (Lord Kelvin), solar chemistry,138;magnetic influence of the sun,161tidal strains,257rotation of the earth,273dynamical theory of solar heat,311312
Thraen, period of Wells's comet,357
Tidal friction, effects on moon's rotation,271272318;month lengthened by,316318influence on planets,319-322on development of binary systems,420
Tietjen, asteroidal orbits,284
Tisserand, capture of comets,98;lunar acceleration,273revolutions of Neptune's satellite,305stationary radiants,341perturbations of Algol,391director of Paris Observatory,414
Titius, law of planetary intervals,71,72,85
Todd, eclipse of 1887185;solar distance,236241trans-Neptunian planet,306
Tornaghi, halo round Venus,254
Transit instrument,120
Trépied, reversal of Fraunhofer spectrum,172
Troughton, method of graduation,122
Trouvelot, veiled spots,148;chromosphere in 1878175intra-Mercurian planets,181250observations of prominences,184196204of Mercury,245247rotation of Venus,252red spot on Jupiter,296
Trowbridge and Hutchins, carbon in sun,212
Tschermak, origin of meteorites,339
Tupman, transit expedition,235;results,236
Turner, polariscopic coronal photography,189;employment of cœlostat,190438stationary radiants,341
Ulloa, eclipse of 177869
United States, observatories founded in,6,7
Uranus, discovery,5,74,111;unexplained disturbances,78,79,307satellites,87,303equatoreal markings,303304spectrum,304305retrograde rotation,313315322
Valerius, darkening of sun's limb,221
Vassenius, description of prominences,68
Venus, transits,4,229232;of 1874233-236of 1882239240atmosphere,236253254mountains,252253spectrum,254albedo,255ashen light,255256pseudo-satellite,256effects upon, of solar tidal friction,320
Very, temperature of sun,220;lunar heat,270
Vesta, discovery,75,76;diameter,287spectrum,288
Vicaire, solar temperature,218
Vico, comet discovered by,97;rotation[Pg 488]rotationof Venus,251Cytherean mountain,253
Violle, solar temperature,218219;solar constant,225Vogel, H. C., solar rotation,202;solar atmospheric absorption,222224spectrum of Mercury,245of Venus,255of Vesta,288of Jupiter,290of Jupiter's satellites,293of Uranus,304rotation of Venus,252ashen light,256intrinsic light of Jupiter,291cometary spectra,342343355357carbon in stars,374; stellar development,375376spectrum of Γ Cassiopeiæ,378of Nova Cygni,393of Nova Andromedæ,395spectroscopic star catalogue,381radial motion of Sirius,386period of Mizar,388eclipses of Algol,390components of Nova Aurigæ,397spectrographic determinations of radial motion,405406
Vogel, H. W., spectrum of hydrogen, 206note,383
Vulcan, existence predicted,248;pseudo-discoveries,249250
Wadsworth, coronal photography,189
Ward, Nova Andromedæ,394
Waterston, solar temperature,218;meteoric infalls,311
Watson, fallacious observations of Vulcan,181250;asteroidal discoveries,284
Webb, comet of 1861326
Weber, Baily's Beads,62;illusory transit of Vulcan,249
Weinek, study of lunar photographs,268
Weiss, comets and meteors,332334
Wells, comet discovered by,356
Wesley, drawings of corona,175
Wheatstone, spectrum of electric arc,132;method of ascertaining light-velocity,232
Whewell, stars and nebulæ,422
Williams, A. Stanley, canals of Mars,279;markings on Jupiter,295297; rotation,296Nova Persei,400
Wilsing, solar rotation from faculæ,155;density of the earth,261system of, 61 Cygni,419
Wilson, Alexander, perspective effects in sun-spots,53,154
Wilson, H. C., red spot on Jupiter,295;compression of Uranus,304exterior nebulosities of Pleiades,411
Wilson, W. E., solar temperature,220222;ultra-Neptunian planets,306
Winnecke, comet discovered by,94;distance of the sun,231Donati's comet,324347
Wisniewski, last glimpse of 1811 comet,99
Witt, discovery of Eros,284
Wolf, C., objections to Faye's cosmogony,315;origin of Phobos,321
Wolf, Max, photographic discoveries of minor planets,283284;Nova Andromedæ,394Nova Aurigæ,396nebula near Nova Persei,401photographic nebular survey,412galactic nebulosity,425
Wolf, R., sun-spot and magnetic periodicity,128162163;analogy of variable stars,128392auroræ,129suspicious transits,249
Wollaston, ratio of moonlight to sunlight,49;flame spectra,131lines in solar spectrum,133
Woods, coronal photography,179180;Cape Durchmusterung,412
Wrangel, auroræ and meteors,335
Wright, G. F., Ice Age in North America,260
Wright, Thomas, theory of Milky Way,14;structure of Saturn's rings,299
Wright, W. H., polarisation of cometary light,355;spectrum of nebulæ,400
Yerkes, donation of a telescope,433
Young, Miss Anne, nebular hypothesis,314
Young, C. A., spectrum of sun-spots,156;origin,158spectrum of corona,170177detection of reversing layer,171172prominences and chromosphere,194-196200photograph of a prominence,197spectroscopic measurement of sun's rotation,202solar cyclones and explosions,204205basic lines,207spectrum of Venus,254red spot on Jupiter,294observations of Uranus,303304Andromedes of 1892337spectrum of Tebbutt's comet,355of Nova Andromedæ,395
Young, Thomas, absorption spectra,136
Zach, Baron von, promotion of astronomy,5,6,28;Baily's Beads,62search for missing planet,72rediscovery of Ceres,74use of a heliostat,120
Zantedeschi, lines in solar spectrum,134;lunar radiation,269[Pg 489]lunar radiation,269
Zenger, observations on Venus,253255
Zenker, cometary tails,348
Zezioli, observation of Andromedes,334
Zodiacal light, relation to medium of space,94;to solar corona,176; meteoric constitution,310
Zöllner, electrical theory of comets,99,344346347;solar constitution,158observations of prominences,194196reversion spectroscope,202solar temperature,220Mercurian phases,245albedo of Venus,255of Jupiter,290of Saturn,303of Uranus,304condition of Venus,256of great planets,289Jovian markings,297ages of stars,375polarising photometer,420421