INTRODUCTION. 5 



thus retain the highly ancient, simple,, and natural division 

 of creation into the Heavens and the Earth, as preserved to 

 us in the earliest monuments of all nations. 



If already, in the course of the last volume, in passing 

 from the consideration of the heaven of the fixed stars in 

 which countless suns shine either singly, or revolving round 

 each other, or are known to us only as constituting the faint 

 light of distant nebulae, we felt the transition to our own 

 planetary system to be a descent from the great and universal 

 to the relatively small and special, the field of contemplation 

 becomes restricted within yet far narrower limits, in passing, 

 as we are now to do, from the totality of the varied solar 

 system to one only of the planets which circle round its 

 central luminary. The distance of the nearest of the fixed 

 stars, a Centauri, is still 263 times greater than the dia- 

 meter of the solar system taken to the aphelion of the comet 

 of 1680, and yet the latter distance is itself 853 times 

 greater than that of our Earth from the Sun. (Kosmos, 

 Bd. iii. S. 582; Engl. p. 261). These numbers (in which 

 the parallax of a Centauri is taken at 0"*9187) assign 

 approximately the distance of a comparatively near region 

 of sidereal space from the conjectured outermost limit of the 

 solar system, and the distance of this latter limit from the 

 Earth. 



Uranology, which occupies itself with the contents of the 

 remote regions of space, still preserves its ancient prerogative 

 of affecting the imagination by the most powerful impres- 

 sions of the sublime, the inconceivable vastness of the rela- 

 tions of space and number which it presents, the recognised 

 order and law which govern the movements of the celestial 

 bodies, and lastly, from the tribute of our admiration called 



