132 



MR. F. McCLEAN ON THE COMPARATIVE PHOTOGRAPHIC 



TABLE of Distribution of Gaseous Neblure and of Stellar Types. 

 Stars to the 3| Magnitude. 



NOTF. The gaseous nebulce are those given in the table in FROST'S edition of 

 SCHEIXEK'S 'Astronomical Spectroscopy.' 



Wo gather from this table that as the stellar types of spectra become more 

 advanced they are found to be more evenly distributed in space. It suggests the 

 idea that stars of the solar type Division IV. started on their career as helium stars 

 of Division I., before the condensation of the galaxy. 



The Procyon stars of Division III. possibly followed in the same course after the 

 galaxy was formed. The paucity of stars of this type in the lower polar region, 

 coupled with their even distribution in tbe other areas, suggests the idea that the 

 sun itself is situated near the lower boundary of the galaxy. 



The distribution of the Sirian stars Division II. is irregular, and further 

 information is required as to their distribution in the southern areas. 



The Orion stars Division I. are mostly confined to the galactic zones. It has 

 been already conjectured that they are still in the first stage of stellar development 

 from the gaseous nebulas. 



It has been throughout assumed that the successive types or divisions are merely 

 the manifestations of the successive physical states, through which every star 

 naturally passes in the course of its career. 



