1888.] 



of the various Species of Heavenly Bodies. 



83 



vapours at a very high temperature — teste the line-absorption spectrum 

 now beginning to replace the flutings — balance the absorption of the 

 meteoric nuclei. 



Anything which in this condition of light-equilibrium will increase 

 the amount of incandescent gas and vapour in the interspaces will- 

 bring about the appearance of the hydrogen lines as bright ones. 

 The thing above all things most capable of doing this in a most 

 transcendental fashion, is the invasion of one part of the swarm by 



Fig. 18. — Explanation of the variability of bodies of Group II. (2.) Medium 

 variation. In this case, there will be a greater number of collisions at perias- 

 tron than at other parts of the orbit. The variation in the light, however, will 

 not be very great under the conditions represented, as the revolving swarm never 

 gets very near the middle of the central one. 



another one moving with a high velocity. This is exactly what I 

 postulate. The wonderful thing under these circumstances then 

 would be that bright hydrogen should not add itself to the bright 

 carbon, not only in bright-line stars, but in those the spectrum of which 

 consists of mixed flutings, bright carbon representing the radiation. 



I now propose to use this question of variability in Group II as t 

 further test of my views. 



G 2 



