i2 pliny's NATUEAL HISTOET. [Book II. 



him at their morning setting, they become invisible and pass 

 beyond him. They then rise in the evening, at the distances 

 which were mentioned above. After this they return back 

 to the sun and are concealed in their evening setting. The 

 star Venus becomes stationary when at its two points of 

 greatest elongation, that of the morning and of the eveniug, 

 according to their respective risings. The stationary points 

 of Mercury are so very brief, that they cannot be correctly 

 observed. 



CHAP. 13. — WHY THE SAME STAES APPEAE AT SOME TIMES 

 MOEE LOPTY AND AT OTHEE TIMES MOEE NEAE. 



The above is an account of the aspects and the occultations 

 of the planets, a subject which is rendered very complicated 

 by their motions, and is involved in much that is wonderful ; 

 especially, when we observe that they change their size and 

 coloiu*, and that the same stars at one time approach the 

 north, and then go to the south, and are now seen near the 

 earth, and then suddenly approach the heavens. If on this 

 subject I deliver opinions different from my predecessors, I 

 acknowledge that I am indebted for them to those indivi- 

 duals who first pointed out to us the proper mode of inquiry; 

 let no one then ever despair of benefiting future ages. 



But these things depend upon many different causes. The 

 first cause is the nature of the circles described by the stars, 

 which the Grreeks term a-psides^, for we are obliged to use 

 Grreek terms, Now each of the planets has its own circle, 

 and this a different one from that of the world^ ; because the 

 earth is placed in the centre of the heavens, with respect to 

 the two extremities, which are called the poles, and also in 



fi'om the Sim at wliich Yentis and Mercury become stationary, and when 

 they attain theu' greatest elongations ; Ajasson, ii. 328, 329. According 

 to Ptolemy, Magn. Constr. hb. viii. cap. 7, the evening setting of Yenus 

 is at 5° 40' fi-om the sun, and that of Mercmy at 11° 30'. 



^ " ' Ai//js, hgneus rotse ch'culus, ab utttu) necto;" Hederic in loco. The 

 term is employed in a somewhat different sense by the modem astrono- 

 mers, to signify the point in the orbit of a planet, when it is either at the 

 greatest or the least distance from the earth, or the body about which it 

 revolves ; the former being tei'med the apogee, aphehon, or the higher 

 apsis ; the latter the perigee, perhelion, or lower apsis ; Jennings on the 

 Globes, pp. 64, 65. 



i "mundo." 



