o68 SCIENTIFIC RECORD FOR 1885. 



discrepancy, had himself at one time or another registered the star as 

 being- of the second type, i.e., without bands, or- else had especially re- 

 marked on the extreme feebleness of the bands which he thonght he 

 saw. There are, however, three stars observed by D'Arrest for which 

 the evidence of change seems stronger, viz, Lai. 24034, D M. + 60°, 

 1461, and DM. + 36°, 2772. Professor Dnuer has also failed to find 

 Schjellerup 249, which is, perhaps, a long period variable, and he draws 

 special attention to R AudromediB, a star the spectrum of which, 

 though of type III a, presents some very marked peculiarities. Great 

 care has been taken in the determination of the position of the bands in 

 the different spectra. It is clear, as many spectroscopists have already 

 observed, that the bands of type III a occupy the same i)Ositions in all 

 the spectra of the type, and the same is true for the bands of type III 

 1). With regard to the former class, the sharp dark edges on the more 

 refrangible sides of the bands generally coincide with strong metallic 

 lines. Thus one of the most prominent bands is terminated by the b 

 lines of magnesium. The nature of the connection between the bands 

 and these metallic lines is not at all clear at present, the symmetrical ar- 

 rangement of the bands seeming to suggest that they are due to some 

 one substance rather than to several. Thethree principal bands of the 

 spectra of the other type Professor Dun6r considers to be unmistakably 

 those of a carbon compound, and to correspond to the bright bands so 

 familiar in the spectra of comets. The determinations of the wave- 

 lengths of the bands in spectra of this type are necessarily not quite so 

 accurate as those of the bands in spectra of type III a, but if Professor 

 Dun^r's measures are accepted, this most important corresj)()ndence 

 may be considered fully established. But apart from the value of these 

 measures. Professor Dun^r's catalogue, with the fnll and clear descrip- 

 tions he has appended to every star, will be of the utmost service to 

 future observers of these interesting and beautiful objects." {Observa- 

 tory, November, 1885.) 



Bright lines in stellar spectra. — "Mr. O. T. Sherman has continued his 

 researches on the spectra of ;/ CassiopeiiB and /i Lyrre. and announces in 

 the American Journal of Science for December the discovery of no fewer 

 than fifteen bright lines in the spectrum of the former star and seventeen 

 in that of the latter. The lines seen in ;/ Cassiopeia are as follows : Ho', 

 A 6356, 6160, D3, A 5840, 5557-5, 5422, 5309-8, 5167-5, 4990, H/i, A 4623, 

 B.y, A 4180, and ^6, bright lines; and A 6280, 5760, 5020, 4920, 4673-5, 

 and 3993, dark lines. The bright lines agree closely in position with 

 the principal lines observed by Professor Young in the spectrum of the 

 chromosphere. Mr. Sherman has also examined a large number of 

 other stars, and Hn each case many or few bright lines have been seen, 

 lines, so far as I know, formerly unsuspected,' It is clear, if Mr. Sher- 

 man's observations can be satisfactorily confirmed, that we have here 

 a most important discovery J but, looking to the fact that these stars 



