BOOK II. VI. 32-36 



and among tliem the sun and moon, follow a course 

 contrary to that of the world, namely to the left, 

 the world always running to the right. (3) Although 

 they are borne on by it and carried westward with an 

 unceasing revolution of immeasurable velocity, 

 nevertheless they travel with an opposite motion 

 along their respective tracks. (4) Thus it comes 

 about that the air is not massed in a dull lethargic 

 ball by revolving in the same direction because of 

 the eternal rotation of the world, but is scattered into 

 separate portions by the opposite impact of the stars. 

 (5) Saturn is of a cold and frozen nature. The orbit 

 of Jupiter is much below it and therefore revolves 

 much faster, completing one rotation every twelve 

 years. The third star is Mars, called by some Her- 

 cules ; owing to the proximity of the sun it has a 

 fiery glow ; it revolves once in about two years, and 

 consequently, owing to its excessive heat and Saturn's 

 frost, Jupiter being situated between them combines 

 the influence of each and is rendered healthy. (6) 

 Next, the sun's course is divided into 360 parts, but 

 in order that an observation taken of the shadows 

 that it casts may come round to the starting-point, 

 five and a quarter days per amium are added ; con- 

 sequently to every fourth " year an intercalary day 

 is added to make our chronology tally with the course 

 of the sun. 



Below the sun revolves a very large star named 

 Venus, which varies its course alternately, and whose 

 alternative names in themselves indicate its rivalry 

 with the sun and moon — when in advance and rising 

 before dawn it receives the name of Lucifer, as being 

 another sun and bringing the dawn, whereas when it 

 slunes after sunset it is named Vesper, as prolonging 



191 



