BOOK II. xxxviii. 104-XXXIX. 106 



the phenomena caused by the air, as most men 

 attribute the hurhng of thunderbolts and light- 

 ning to the winds' violence, and indeed hold that 

 the cause of the rain of stones that sometimes occurs 

 is that the stones are caught up by the wind ; and 

 Ukewise many other things. On this account more 

 facts have to be set out at the same time. 



XXXIX. Storms and rain obviously have some Rain. 

 regular causes, but some that are accidental, or at 

 all events not hitherto explained. For who can 

 doubt that summer and winter and the yearly 

 vicissitudes observed in the seasons are caused by 

 the motion of the heavenly bodies? Therefore as 

 the nature of the sun is understood to control the 

 year's seasons, so each of the other stars also has 

 a force of its own that creates effects corresponding 

 to its particular nature. Some are productive of 

 moisture dissolved into hquid, others of moisture 

 hardened into frost or coagulated into snow or 

 frozen into hail, others of a blast of air, others of 

 warmth or heat, others of dew, others of cold. But 

 it must not be thought that the stars are of the size 

 that they appear to the sight, since the consideration 

 of their immense altitude proves that none of them 

 is smaller than the moon. Consequently each of 

 them exercises its own nature in its own motion, a 

 fact which the transits of Saturn in particular make 

 clear by their storms of rain. Nor does this power rn/iumce oj 

 belong to the moving stars only, but also to many of ll^ig^on 

 those that are fixed to the sky, whenever they are weaUter, 

 impelled forward by the approach of the planets or 

 goaded on by the impact of their rays, as we observe 

 occurring in the case of the Little Pigs, the Greek 

 aame for which is consequently the Hyades, a word 



249 



