60 



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



relative quantity, gets more intense. The second band at 473 in the 

 bine gets brighter as well as the one at 517. We have now bands 

 9 and 10 added. This reduced spacing increases the number of col- 

 lisions, so that Pb and Ba are added to Mg, Fe, and Mn. We have 

 the bands 2, 3, 4, 5, 6, 7, 8, 9, and 10. This is the condition which 

 gives, so to speak, the normal spectrum. 



(4) This increased action will give us a bright atmosphere round 

 each meteorite, only the light of the meteorite in the line of sight 

 will be absorbed : we shall now have much continuous spectrum from 

 the interspaces as well as the vapour of carbon. The absorption 

 Hidings will pale, and the Mg flatings will disappear on account of the 

 higher temperature, while new ones will make their appearance. 



(5) Greater nearness still will be followed by the further dimming 

 of the bright carbon flutings including the one at 517. The blue end 

 of the spectrum will shorten as the bands fade, narrow, and increase 

 in number. If the star be bright, it will now put on the appearance 

 of a. Orionis ; if dim, only the flutings of Fe and Mn (1), bands 2 and 

 3, will remain prominent. 



(6) All the flutings and bands gradually thin, fade, and disappear. 

 A star of the third group is the result. 



In the latter higher-temperature stages we must expect hydrogen 

 to be present, but it need not necessarily be visible, as the bright 

 lines from the interspaces may cancel or mask the absorption in the 

 line of sight of the light of the meteorites ; but in case of any violent 

 action, such as that produced by another swarm moving with great 

 velocity, we must expect to see them bright, and they are shown 

 bright in a magnificent photograph of o Ceti, taken for the Draper 

 Memorial, which I owe to the kindness of Professor Pickering. I 

 shall return to this question. 



Stages antecedent to those recorded by Duner. 



So far I have referred to the swarms observed by Daner. The 

 result of the discussion has been to show that all the phenomena are 

 included in the hypothesis that the final stages we have considered 

 are antecedent to the formation of stars of Group III, bodies which 

 give an almost exclusively line absorption, though these bodies are 

 probably not yet stars, if we use the term star to express complete 

 volatilisation, similar to that observed in the case of our sun. 



The qnestion then arises, Are all the mixed fluting stages really 

 included among the objects already considered ? 



It will be remembered that in my former communication I adduced 

 evidence to the effect that the mixed fluting stage was preceded by 

 others in which the swarms were still mere dispersed, and at a lower 

 temperature. Th 6 first condition gives us bright hydrogen ; the last 

 little continuous spectrum to be absorbed, so that the spectrum is one 



