CHANGE IN THE HEAVENS. 115 



grouping of the stars (on which we have commented in 

 Book L), the Ram, the Bull, the Twins, the Crab, the Lion, 

 the Virgin, the Balance, the Scorpion, the Archer, the Cow, 

 the Water-bearer, the Fishes. There are twelve, three for 

 each season. The constellations represented by these figures, 

 so singularly chosen, spread over the whole celestial vault, 

 that is, over an extent of 360. 



To resume. 



The heavens, like earth, have their annals : everything 

 changes there as in the human world. In the age of Hip- 

 parchus, or some two thousand years ago, the sun entered, 

 at the spring equinox, into the zodiacal sign of Aries ; in 

 the summer solstice, it entered into that of Cancer; at the 

 autumnal equinox, into Libra; and at the winter solstice, 

 into Capricorn. These signs then corresponded exactly to 

 the constellations which they represent. 



Now, whatever Aristotle and his disciples may say, the 

 firmament is not incorruptible (apdagro;) and immovable ; 

 even the fixed stars, as we call them, change their place in 

 time. We have seen that the whole celestial vault or " right 

 sphere" runs, from east to west, around the poles of the 

 world; we have seen also that the sun moves, on his own 

 account, from west to east, around the poles of the oblique 

 sphere, or the Ecliptic. Well, this does not suffice; there 

 is a third movement to be observed, that of the right sphere 

 itself round the poles of the Ecliptic ; and this, not like that 

 of the sun, from west to east, but inversely, from east to west. 



