xxvin PROGNOSTICATIONS FROM COMETS 303 



immediate future, but that it has them stored up and 

 buried deep within by the laws of the universe. The 

 comet which appeared in the consulship of Paterculus 

 and Vopiscus fulfilled the anticipations of this kind 

 entertained by Aristotle, and for that matter by 

 Theophrastus ; for there were everywhere severe 3 

 and prolonged storms, while in Achaia and Macedonia 

 cities were overturned by earthquakes. The slow- 

 ness of the comets' motion, Aristotle says, is a proof 

 that they are rather heavy, containing much earthy 

 matter. So are their orbits too, for they are usually 

 confined to the neighbourhood of the poles. 



XXIX 



BOTH statements are false. Let me take them in i 

 their order. Well, it is asserted, is it, that all 

 bodies are heavy that move more slowly ? What ! 

 is the planet Saturn, which accomplishes its circuit 

 most slowly of all the planets, heavy? It has, in 

 fact, a proof of lightness in being higher than all 

 the rest. But, you 'say, it takes a wider sweep, and 

 does not go more slowly than the others, but only 

 a longer distance. Let me suggest that I can 

 make the same statement of the comets ; even if 

 their ; course is more sluggish, they have farther 

 to go. But it is a falsehood to assert that they 2 

 move more slowly. For this last comet traversed 

 within six months half the span of heaven ; the 

 previous one withdrew from sight in a shorter 

 period. But again, it is urged, on account of their 

 weight, they are borne down lower. Well, in the first 

 place, a comet is not borne down, bat round. In 

 the second, this recent one began its motion in the 



