xiii THEIR CAUSE 37 



some chance has so disposed the clouds that they 

 face one another, one of them reflects the image of 

 the sun, the other the image of his image. The 

 clouds that produce this effect must be dense, 

 smooth, bright and flat, analogous in character to 

 the sun. All phantoms of this kind are white and 

 resemble so many discs of the moon, for the reason 

 that the sun s light that they receive and reflect 

 back is always oblique. If the cloud, on the con- 3 

 trary, is beneath the sun and too near him, his rays 

 dispel it : or again, if situated too far away, it does 

 not reflect them nor produce any image. In 

 ordinary experience in the same way mirrors with 

 drawn to a distance from us do not reproduce our 

 features because our sight cannot carry back to us 

 from them. 



These suns, too to employ the name given by 

 the chroniclers, are an indication of rain, especially 

 if they have their position in a southern quarter, 

 from which the most heavily-charged clouds chiefly 

 come up. When such an image surrounds the sun 

 on both sides, then, if we are to believe Aratus, 

 a storm is brewing. 



XIV 



IT is now high time that I ran over the other i 

 varieties of celestial fires, whose forms are diverse 

 one from the other. Sometimes there is a shooting 

 star, sometimes there are glowing lights, which are 

 occasionally stationary, sticking to one spot, and at 

 times able to rush through the air. Several species 

 of these may be observed. There are, for example, 

 Bothynae (cave -like meteors) when within an 

 outer circle there is a blazing gulf in the sky like a 



