BOOK II. Lix. 149-LX. 151 



that the divining powers of Anaxagoras covered a 

 greater marvel, and that our understanding of the 

 physlcal universe is annihilated and everything thrown 

 into confusion if it is beheved either that the sun is 

 itself a stone or ever had a stone inside it. But it 

 will not be doubted that stones do frequently fall. A 

 stone is worshipped for this reason even at the present 

 day in the exercising ground at Abydos — one of 

 moderate size, it is true, but which the same Anax- 

 agoras is said to have prophesied as going to fall in the 

 middle of the country. There is also one that is wor- 

 shipped at Cassandria, the place that has been given 

 the name of Potidaea," and where a colony was 

 settled on account of this occurrence. I myself 

 saw one that had recently come down ^' in the territory 

 of the Vocontii. 



LX. The common occurr ences that we call rainbows Rairtbows. 

 have nothing miraculous or portentous about them, 

 for they do not reliably portend even rain or fine 

 weather. The obvious explanation of them is that 

 a ray of the sun striking a hollow cloud has its point 

 repelled and is reflected back to the sun, and that the 

 diversified colouring is due to the mixture of clouds, 

 fires and air. Rainbows certainly do not occur except 

 opposite to the sun, and never except in semi-circular 

 shape, and not at night time, although Aristotle 

 does state that a rainbow has been sometimes seen at 

 night, though he also admits that it cannot happen 

 except on the 14th day of the lunar month.'' Rain- 

 bows in winter occur chiefly when the day is drawing 

 in after the autumnal equinox ; when the day draws 

 out again after the vernal equinox they do not occur, 

 nor in the longest days about the solstice, but they 

 occur frequently in midwinter '^ ; also they are high 



287 



