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SOME HANDBOOKS 
the earth, represented e.g. by mountains, are negligible in 
comparison with the size of the whole, he quotes Eratosthenes 
and Dicaearchus as claiming to have discovered that the 
perpendicular height of the highest mountain above the normal 
level of the land is no more than 10 stades; and to obtain the 
diameter of the earth he uses Eratosthenes’s figure of approxi 
mately 252,000 stades for the circumference of the earth, 
which, with the Archimedean value of for tt, gives a 
diameter of ‘about 80,182 stades. The principal astronomical 
circles in the heaven are next described (chaps. 5-12, pp. 
129-35); then (chap. 12) the assumed maximum deviations in 
latitude are given, that of the sun being put at 1°, that of the 
moon and Venus at 12°, and those of the planets Mercury, 
Mars, Jupiter and Saturn at 8°, 5°, 5° and 3° respectively; the 
obliquity of the ecliptic is given as the side of a regular polygon 
of 15 sid&s described in a circle, i.e. as 24° (cfiap. 23, p. 151). 
Next the order of the orbits of the sun, moon and planets is ex 
plained (the system is of course geocentric); we are told (p.138) 
that ‘ some of the Pythagoreans ’ made the order (reckoning 
outwards from the earth) to be moon, Mercury, Venus, sun, 
Mars, Jupiter, Saturn, whereas (p. 142) Eratosthenes put the 
sun next to the moon, and the mathematicians, agreeing with 
Eratosthenes in this, differed only in the order in which they 
placed Venus and Mercury after the sun, some putting Mercury 
next and some Venus (p. 143). The order adopted by ‘some 
of the Pythagoreans ’ is the Chaldaean order, which was not 
followed by any Greek before Diogenes of Babylon (second 
century B.c.); ‘some of the Pythagoreans’ are therefore the 
later Pythagoreans (of whom Nicomachus was one); the other 
order, moon, sun, Venus, Mercury, Mars, Jupiter, Saturn, was 
that of Plato and the early Pythagoreans. In chap. 15 
(p. 138 sq.) Theon quotes verses of Alexander ‘the Aetolian’ 
(not really the ‘ Aetolian ’, but Alexander of Ephesus, a con 
temporary of Cicero, or possibly Alexander of Miletus, as 
Chalcidius calls him) assigning to each of the planets (includ 
ing the earth, though stationary) with the sun and moon and 
the sphere of the fixed stars one note, the intervals between 
the notes being so arranged as to bring the nine into an 
octave, whereas with Eratosthenes and Plato the earth was 
excluded, and the eight notes of the octachord were assigned