40 pliny's natxjeal histoet. [Book n. 



CHAP. 11. (14.) — OF THE MOTION" OF THE MOON. 



It is certain that the moon, having her horns always turned 

 from the sun, when she is waxing, looks towards the east ; 

 when she is waning, towards the west. Also, that, from the 

 second day after the change, she adds 47^ minutes^ each day, 

 until she is full, and again decreases at the same rate, and 

 that she always becomes invisible when she is within 14 de- 

 grees of the sun. This is an argument of the greater size of 

 the planets than of the moon, since these emerge when they 

 are at the distance of 7 degrees only^. But their altitude 

 causes them to appear much smaller, as we observe that, 

 during the day, the brightness of the sun prevents those 

 bodies from being seen which are fixed in the firmament, 

 although they shine then as well as in the night : that this 

 is the case is proved by eclipses, and by descending into very 

 deep wells. 



CHAP. 12. (15.) — OF THE MOTIONS OF THE PLANETS AND 

 THE GENEBAL LAWS OP THEIE ASPECTS'. 



The three planets, which, as we have said, are situated 

 above the sun"*, are visible when they come into conjunction 

 with him. They rise visibly^ in the morning, when they are 

 not more than 11 degrees from the sun® ; they are afterwards 

 directed by the contact of his rays'', and when they attain 

 the trine aspect, at the distance of 120 degrees, they take 

 their morning stationary positions®, which are termed pri- 



1 In a subsequent part of the work, xviii. 75, the author gives a dif- 

 ferent rate of increase, viz. 51^ minutes ; neither of these numbers is 

 correct ; the mean rate of increase being, according to Alexandre, about 

 54' or 55' ; Lemaire, ii. 261, 262. See also Marcus in Ajasson, ii. 311-14. 



2 It is scarcely necessary to remark, that the effect, as here stated, has 

 no connexion with the supposed cause. 



3 " luminum canonica." * Mars, Jupiter, and Saturn. 



5 They are then said, in astronomical language, to rise hehacaUy. 



6 In the last chapter this distance was stated to be 7 degrees ; see the 

 remarks of Alexandre, in Lemaire, ii. 263, 



7 " radiorum ejus contactu reguntur." The doctrine of the ancient 

 astronomers was, that the motions of the planets are always governed by 

 the rays of the sun, according to its position, attracting or repelling them. 



^ A planet appears to be stationary, i. e. to be referred to the same 

 point of the zodiac, when it is so situated with respect to the earth, that 



