INDEX. 



457 



Tacchini' s observations on prominence 



lines, 344 



welling-up of metallic strata, 413 

 Taylor, Mr., abstract prepared by, 



392 



Telespectroscope, Newall's, 98, 99 

 Telluric lines, 65 

 Temperature, effect of, on spectrum 



of calcium, 241 

 effect of, on spectrum of lithium, 



241 



effect of, on spectrum of magne- 

 sium, 241 

 function of, 399 

 molecular grouping simplified by, 



explanation of, 260, 261 

 Thalen, cobalt in sun, 89 



comparison of lines of elements 



with Fraunhofer lines, 177 

 titanium in sun, 89, 92 

 method of work, 91 

 statement on basic lines, 371 

 Theory of exchanges, example of, 56 

 Thomson, Sir Wm., statement of 

 the bases of Stokes's explanation, 51 

 Titanium, experiments on, Thalen, 92 

 in sun, Thalen, 89 

 lines after reduction in, coincident 

 with those in other substances, 

 235 

 lines most widened in sun-spots, 



321 



Triplets, changes of, 293 

 origin of, probable, 334 

 in spectrum of iron, 333 

 Trouvelot, solar observations, 415 ; 



veiled spots, 409 

 Turner's observations of eclipse of 



1886, 364 



Tyndall's observations on spectrum of 

 lithium, 197 



U. 



Uranium in sun, 158 

 V. 



Vapour densities, 269, 281 

 potassium, Eoscoe, 277 

 sodium, Eoscoe, 277 

 Vapours, spectra of, with changing 



density, 283 



Variable bands, cause of, 43 

 Venus, spectrum of, observations on, 

 19 



Vibration, sympathetic, experiment 



in, 61 



Vogel quoted, 369 

 Vogel's list of lines in spectrum of 



prominences, 184 



W. 



Wave-lengths of light, determination, 



86 



Angstrom's map, 88 

 Wheatstone employs electricity in 



spectroscopic work, 73 

 Winds, solar, to some extent cyclonic, 



138 

 solar, at sun's limb, determination 



of velocity of, 134 

 solar, velocity of, 137 

 Winlock, ring-slit method, 114 

 Wollaston discovered that solar spec- 

 trum is not continuous, 10 

 first effects of purification of spec- 

 trum, 24 



first used slit in spectroscope, 23 

 founds spectrum analysis, 12 

 observations on spectrum of a 



candle, 28 



Wiillner's experiments on spectra of 

 elementary bodies, 193 



Young, accepts classification of pro- 

 minences, 116 



fine lines in spot-spectrum, 407 

 metallic prominence, 416 

 observation on reversal of hydro- 

 gen line on sun's disc, 117 

 observations on prominences, 417 ; 

 the spectrum of chromosphere, 

 327, 335 ; on the spectra of pro 

 minences, 185, 331 ; on sun- 

 spots, 255 



views on the new hypothesis, 352 

 on solar volcanoes, 423 



Z. 



Zinc, vapour of, 276 



present in solar atmosphere, 77 

 Zollner, accepts classification of pro- 

 minences, 116 



method of viewing forms of pro- 

 minences, 113 

 Zones of spots, 429 



