BOOK II. VI. 44-vn. 47 



30th day at latest sets out again on the same course — 

 being perhaps our teacher as to all the facts that it 

 has been possible to observe in the heavens ; (1) that 

 the year is to be divided into twelve monthly 

 spaces, because she herself that number of times 

 folloAvs the sun in his return to his starting point ; 

 (2) that she is governed by the sun's radiance as are 

 the rest of the stars, as in fact she shines with a hght 

 entirely borrowed from him, Hke the Hght which we 

 see flickering reflected in water ; (3) that conse- 

 quently she only causes water to evaporate with a 

 rather gentle and imperfect force, and indeed 

 increases its quantity, whereas the sun's rays dry it 

 up ; (4) also that the reason why she is seen to vary 

 in her light is that she is full only when opposite to 

 the sun, and on the remaining days shows as much 

 Hght from herself to the earth as she herself con- 

 ceives from the sun ; though (5) she is indeed 

 invisible when in conjunction with the sun, because 

 being turned towards him she gives back the entire 

 draught of Hght to the source from which she receives 

 it ; (6) but that the stars are undoubtedly nourished 

 by the moisture of the earth,'' since she is sometimes 

 seen spotted in half her orb, clearly because she has 

 not yet got sufficient strength to go on drinking — 

 her spots being merely dirt from the earth taken up 

 with the moisture ; (7) but that her ecHpses and EcHpxe 

 those of the sun, the most marvellous and indeed 

 portentous occurrence in the whole of our observa- 

 tion of nature, serve as indications of their dimensions 

 and shadow. VII. It is in fact obvious that the 

 sun is hidden by the passage across it of the moon, 

 and the moon by the interposition of the earth, and 

 that they retaHate on one another, the same rays of 



197 



