452 



INDEX. 



Gold-copper alloys, research on, 152 

 results of Faraday's researches, 



279 



Grating, diffraction, devised by 

 Frarmhofer, 83 ; method of 

 making, 85 

 Angstrom's use of, 86 ; Mascart's, 



86 

 Rutherfurd's, 85 



H. 



Hastings, Prof., on absorbing vapour 



in solar atmosphere, 407, 408 

 arrangement for comparison of 



spectra, 103 

 Herschel, Sir William, theory of sun 



destroyed, 80 



Sir John, device for recording 

 spectrum observations, 36 ; ex- 

 periments on coloured lights, 

 35 ; first points out absorption 

 of light, 37 



Captain, observes reversal of 

 hydrogen lines on sun's disc, 

 117 



Hittorf's observation on fluted spec- 

 tra, 179 

 results on multiple spectra, 



190 



Hodgkinson, memorandum on La- 

 voisier's views, 58 

 Hofmann's investigation on spectra 



of metals, 79 

 Holtzmann, Dr., 401 

 Huggins's method of observing pro- 

 minences, 113 

 remarks on spectrum of calcium in 



stars, 248 

 work on stellar spectra, 173, 187, 



203 

 and Miller's list of elements in 



A'ldebran, 187 

 Hunt (Sterry), view on dissociation 



of elements, 206 

 Hydrocarbons, hypothetical spectra 



of, considered, 292 

 table of series of, 265 

 Hydrogen, combination of carbon 



and, 264 

 ejections of, 131 

 in solar atmosphere, explanations 



on, 168 



effect of, in crucibles, 393 

 lines on sun's disc, reversal of, 



Herschel, 117 

 lines widened by pressure, 127 



I, 



Impurities, coincident lines due to, 



154 

 in spectra, method of elimination, 



225 ; result of theory, 251 

 Integration of arc light, 384 

 Intensities, of metals in sun, list of 



variations of, 231 

 variation of experiments on, 239 

 Iodine vapour, spectrum of, 284 



absorption of, 41, 202 

 Iron in sun-spots, lines due to, 317 

 expansion of volume on reaching 



photosphere, 422 

 in sun, 75 



final reduction of spectrum of, 232 

 spectrum of, after reduction, ex- 

 planation of, 234 

 in arc, 384 



in solar atmosphere, 362 

 Kirchhoff, 74 



triplets in spectrum of, 333 

 Iron-lines after reduction, coincident 



with lines in other substances, 



table of, 233 



change of refrangibility of, 347,351 

 change of intensity in, 332 et seq. 

 frequency of, in sun-spots, 340 

 individuality of, 349 

 in spectrum of chromosphere, 335 

 in spots and prominences, Thalen, 



372, 374 ; Angstrom, 372, 374 

 in sun-spots, 338 

 most widened in sun-spots, 320 



J. 



Janssen first applied the method of 



artificial eclipses, 107 

 proves that absorption lines in 

 solar spectrum are due to aqueous 

 vapour, 66 



Janssen's map of telluric lines, 67, 68 

 suggestion on spectroscope, 26 



K. 



Kepler, 5 

 Kirchhoff, 56 



comparison of lines of elements 

 with Fraunhofer lines, 177 



establishes laws for light rays, 54 



hypotheses as regards the sun, 69, 

 161 



investigation on spectrum of 

 metals, 79 



