36 THE SIDEKEAL UNIVERSE. 



star Castor, whose constituents revolve around each other in 

 215 years; Gamma, in the constellation of the Virgin, whose 

 constituents revolve in 628 years ; Gamma of the Lion, whose 

 constituents revolve in 1200 years ; and Mizar and Alcor, in 

 the tail of the Great Bear, which, according to Professor 

 Nichol, would probably consume not much less than the in- 

 conceivable period of 190,000 years in completing a single 

 revolution around each other ! Others accomplish their revo- 

 lutions in much less than 100 years. 



By establishing the fact that rotatory and orbitual motions 

 are experienced by many of the stars, the extreme probability 

 is at the same time established on analogical grounds, that 

 similar motions are experienced, with, perhaps, some modifi- 

 cations, by all stars. We are, at least, not without strong, 

 not to say demonstrative evidence, that motions of this kind 

 are going on in the celestial spaces, on a much grander scale 

 than any we have yet described. By comparing the positions 

 of the stars in the modem heavens with their positions as rep- 

 resented in ancient catalogues, Sir William Herschel found 

 that in one quarter of the firmament, they were apparently 

 drawing nigher together, while in the opposite, quarter they 

 were apparently receding from each other. To account for 

 these changing appearances, Herschel conjectured that our own 

 sun, with all his retinue of planets, was moving in some grand 

 path toward a point in the constellation Hercules. After 

 much doubt and many critical examinations, subsequent 

 investigators have succeeded in establishing this opinion on 

 an indubitable basis. 



But in the hands of Argelander, Struve, Peters, and especi- 

 ally of Maedler, the theory of this solar motion was made to 

 assume still more definite form. Inferring, with others, from 

 analogy, that the path described by our luminary must be the 



