54 Mr. J. N. Lockyer. On the Classification [Apr. 12, 



as already pointed out, great accuracy in this part of the spectrum 

 cannot be expected. 



It may here be mentioned that in the maps which accompany this 

 paper, the compound structure of the hot carbon flutings has been 

 omitted, because the details are not, as a rule, seen in the spectra of 

 heavenly bodies in which there are indications of carbon. The 

 flutings are represented as simple ones beginning at the brightest edge 

 and fading off gradually. 



Chemical Substances indicated by the Absorption Flutings and Bands, 



I may state that I have now obtained evidence to show that the 

 origin of the following absorption flutings is probably as under : — 



Wave-length of 

 less refrangible 

 Ware-length of end, given by Duner 



darkest most as measured in 



No. of Fluting. Origin, refrangible edge. a Orionis. 



2 Fe 616 628 



3 Mn(2) 585 595 



4 Mn(l)* 558 564 



5 ...... Pb(l)t 544 550 



6 BaJ 524 526 



7 Mg 521 517 



8 Mg 500 495 



These flutings are characteristic of the whole class, and D liner's 

 catalogue consists chiefly of a statement of their presence or absence, 

 or their varying intensities, in the different stars. 



He gives other bands and wide lines which he has measured, 

 specially in a Orionis. I have also discovered the origin of the 

 majority of these. They are as follows : — 



Ware -length. 



I. Fluting of Cr (1) 581 



II. ? V 570—577 



III. Fluting of Pb (2) 567 



IV. ? 543 



V. Line of Mn seen in bunsen 538 — 540 



VI. Band of Ba 532—534 



Jl. Fluting of Cr (2) 559§ 

 2. „ „ (3) 536 



3. Line of Cr seen in bunsen 520 



* Means strongest fluting. 



f The second Pb band has been seen in o Scorpii and a Orionis. Owing to an 

 error in the map in the former paper, this fluting was ascribed to zinc. 



% This is the second brightest band, wave-length 525. The first at wave-length 515, 

 is masked by the radiation fluting at 516. See post. 



§ This is not given by Duner. It would be masked by the Mn fluting in the 

 star. I have inserted it to show that we could not be dealing with the 3rd fluting 

 of Cr at 536 if we could not explain the apparent absence of the 2nd. 



