23 
plii^t's i^attjeal histokt. 
[Book II. 
vens are rapidly carried about to tlie riglit^ And altliougli, 
by the stars constantly revolving- with immense velocity, 
they are raised up, and hurried on to the part where they 
set, yet they are all forced, by a motion of their own, in an 
opposite direction^ ; and this is so ordered, lest the air, being 
always moved in the same direction, by the constant whirling 
of the heavens, should accumulate into one mass, whereas 
now it is divided and separated and beaten into small pieces, 
by the opposite motion of the different stars. Saturn is a 
star of a cold and rigid nature, while the orbit of Jupiter is 
much lower, and is carried round in twelve years ^. The next 
star. Mars, Avhich some persons call Hercules^, is of a fiery 
and burning nature, and from its nearness to the sun is carried 
round in little less than two years^. In consequence of 
the excessive heat of this star and the rigidity of Saturn, 
Jupiter, which is interposed between the two, is tempered 
by both of them, and is thus rendered salutary. The path 
of the Sun consists of 360 degrees; but, in order that the 
shadow may return to the same point of the diaP, we are 
obliged to add, in each year, five days and the fourth part of 
a day. On this account an intercalary day is given to every 
fifth year-^, that the period of the seasons may agree with 
that of the Sun. 
^ Our autlior supposes, that the spectator has his face directed towards 
the south, as is the case with the modern observers. We are, however, in- 
formed by Hardouin, that this was not the uniform practice among the 
ancients ; see the remarks of Alexandre in Lemaire, ii. 242, arid of Mar- 
cus in Ajasson, ii. 269. 
2 The constant revolution refers to the apparent daily motion ; the 
opposite direction to their annual course through the zodiac. Ptolemy 
gives an account of this double motion in his Magna Constructio, i. 7. 
3 For the exact period, according to Somerville and Herschel, see 
note 3, p. 27. 
4 Afistotle informs us, that Mars was also called Hercules or Pyrosis ; 
De Mundo, cap. ii. p. 602. See also Apuleius, De Mundo, § 710. Hy- 
ginus is said by Hardouin to give the name of Hercules to the planet 
Mars, but this appears to be an inaccuracy ; he describes the planet under 
its ordinary appellation ; hb. ii. p. 62 ; and ii. 78, 9. 
5 Cicero, speakmg of the period of Mars, says, " Quatuor et viginti 
mensibus, sex, ut opinor, diebus minus ; " De Nat. Deor. For the exact 
period, see note ^, p. 27. 
6 " Sed ut observatio umbrarum ejus redeat ad notas." According to 
the interpretation of Hardouin, " Ad easdem lineas in solari horologio." 
Lemaire, ii. 243. 
7 This is an example of the mode of computation which we meet with 
