( 140 ) 



therefore repeated the computation after exclusion of the c and the 

 ac stars. 



The table (see p. 139) contains the results for all the classes of Maury 

 separately ; class XV is divided into three subdivisions : XV A are 

 those whose spectra agree with that of a Boötis, XV C are those which 

 agree with the redder « Cassiopeiae, while XV ^ embraces all those 

 that cannot with certainty be classed among one of the other two 

 groups. 



The values for T4.0 and g'4.0 differ very little from those of the 

 preceding table. If we take the value of the velocity of the solar 

 system =: 4.2 earth's distances from the sun, the ^''s divided by 4.2 

 yield the mean parallax of stars of different spectral classes for the 

 magnitude 4.0 (.T0.4). Reversely, we derive from the q'^ the relative 

 brightness of these stellar types, for which we have here taken the 

 number which expresses how many times the brightness exceeds 

 that of magnitude 4.0 when placed at a distance for which g = 0". 10,' 

 hence with the parallax 0".024. Finally the last column 2t/5' contains 

 the relation between the mean linear velocities of tlie group of stars 

 and our solar system. 



In the following table we have combined these values in the same 

 way as before. 



Spectrum | Typical 

 Maury I Dr. Cat. star 



4.0 



-74.0 



4.0 



L for 



7=0". 10 



Irjg 



I— III 



IV— V 



VI— VIII 



IX -XII 



XIII— XIV 



XV 

 XVI— XX 



B 

 B-A 

 A 

 F 

 G 

 K 



0.005-' 



0.013 



0.040 



0.101 



182 



0.120 



0.050 



014 

 0.03G 

 0.0G3 

 0.141 

 . 224 

 09G 

 061 



8 

 0.7 

 1.3 

 1.4 

 l.G 

 2.5 

 l.G 



^ 4. Conclusions from this table. The numbers of the last column 

 are not constant but show a systematic variation. Hence the mean 

 linear velocity is not constant for all kinds of stars but increases 

 as further stages of development in the spectral series are readied. 

 (Whether the decrease for the 3''^ type, class M, is real must for 

 the present be left out of consideration). That the linear speed of the 

 Orion stars is small is known and appears moreover from the 



