72 LIGHT SCIENCE FOR LEISURE HOURS. 



brightest of the Pleiades, as the central orb around 

 which all the stars revolve. 



Now to such a problem as this a problem whose 

 grandeur cannot but be recognised even by those who 

 reject the conclusions adopted by Madler the new 

 method of research is applicable with peculiar force. 

 For instance, if the stars of Taurus are circling round 

 a particular orb also in Taurus, it will be manifest, on 

 a moment's consideration, that they can have only a 

 slight motion either of recession or approach with re- 

 spect to the sun. When from our station on the earth 

 we see Venus or Mercury nearly in the same direction 

 as the sun, we know that at the moment either planet 

 has only a thwart motion, being then either at its 

 greatest or least distance from us. So that if the new 

 method were applied to stars in Taurus, and showed 

 that swift motions of recession or approach are there in 

 progress, it would at once dispose of the attractive but 

 too speculative theory of the German astronomer. 



This has not yet been accomplished; in fact, since 

 Dr. Huggins' instrument was mounted and in order, 

 the constellation Taurus has not been well placed for 

 observation by the new method. But in the meantime, 

 evidence of the most convincing nature has been ob- 

 tained to show that Madler's theory is unsound. 



We have seen that the theory was based, in the main, 

 on a certain general community of apparent motion 

 among the stars in Taurus. Madler took it for granted 

 that this community of motion is exceptional. It did 

 not occur to him to examine the motions of stars in 



