456 



INDEX. 



Spectra (continued) 



of elementary bodies, experiments 

 on, Wullner, 193 ; Schuster, 192 



of prominences. See Prominences. 



of simple and compound bodies, 160 



of vapours and lines in spots and 

 prominences, divergencebetween, 

 175 



stellar, -first class of, explanation of, 

 190 ; Fraunhofer, 19 ; Huggins, 

 187, 203 ; typical of, 189 ; varia- 

 tions in, 173 



Spectrometer, Angstrom's, 85 

 Spectroscope, description of, 70 



direct vision, use of, 27 



4-prism, Steinheil's, 71 



improved by Fraunhofer, 13 ; by 

 Simms, 25 ; by Swan, 26 



line slit, why used, 32 



slit of, first used by Wollaston, 23 



suggestion on, Janssen, 23 



telescope in, first used, 25 



theodolite, Fraunhofer, 15 

 Spectrum analysis, birth of, 5 



quantitative, 152 



Spectrum, candle, discovery on, Wal- 

 laston, 28 



of lithium 197 



of metallic vapour mixed _with a 

 gas, 150 



substances have more than one, 179 

 Spbrer accepts classification of promi- 

 nences, 116 



observations on spots, 407, 426, 



430, 434, 435 

 Spot spectra, 100 



compared with prominence spec- 

 tra, 342 



compared with, Liveing and 



Dewar's results, 299 

 Spots, Carrington's observations on, 

 431 



close connection between metallic 

 prominences, 421 



disturbances on following edge of, 

 428 



disturbed, 409 



faculae, follow the formation of a, 

 422 



fewest at equator and poles, 428 



formed along meridians, 433 



how caused, 408 



latitudes of, 421, 429, 430, 436, 

 438, 444 



locality of most rapid proper 

 motions of, Sporer, 428 



maxima and minima, 434, 435 



motion across disc, 426 



Spots (continued) 



observations on, 420 

 proper motion of, 433 

 quiet, 409 

 succession of, 431 

 veiled, 409 



Stellar spectra, Fraunhofer, 19 

 Stannyan first describes prominences, 



97 

 Stars, calcium in, spectrum of, 



Huggins, 246, 248 

 chemical nature of sun as regards, 



172 



genera of, 186 

 independent spectra, 22 

 solar coincidences in, 201 

 spectra of, hottest, lines of hydro- 

 gen in, 244 ; Huggins, 203 ; 

 Huggins and Miller, 173 ; 

 Rutherfurd, 173 ; Secchi, 173 

 variations in spectra of, 173 

 Strata in sun's atmosphere, 304 



metallic, 412 

 Stewart's (Balfour), explanation of 



D lines in solar spectrum, 56 

 law of equivalence of radiation and 



absorption, 63 

 theory of sun-spots, 101 

 Stokes explains cause of sodium in 



sun, 51 

 Stokes' s observations on spectrum of 



a candle, 52 



remark on electric spectra, 147 

 Stoney, 378 

 Strontium in sun, 158 



spectrum of, 380 



Sound, analogies from, Doppler, 133 

 Sulphur vapour, spectrum of, 283 

 Swan, improvement in spectroscope, 

 26 



T. 



Tables : metals in the sun, 219 

 final reduction of iron lines, 233 

 lines in prominences, 182 

 series of hydrocarbons, 265 

 lines most widened in spots, 317, 



321 

 variation of intensity in solar 



metals, 231 



lines observed in spots and pro- 

 minences, 328 

 Tacchini's additions to lines in spectra 



of prominences, 184 

 observations on chemical composi- 

 tion of prominences, 116,117>312 

 observations on variations of spectra 

 of prominences, 317 



