120 COSMOS. 



idea of the relation of the planets and fixed stars to the su/t^s 

 course, the division of the ecliptic into twelve equal partu 

 (Dodecatoraeria), originated with the ancient Chaldeans, and 

 very probably came to the Greeks, at the beginning of tlia 

 ^fth, or even in the sixth century before our era, direct from 

 Chaldea, and not from the Valley of the Nile.* The Greeks 

 merely separated from the constellations named in their prim* 

 itive sphere those which were nearest to the ecliptic, and 

 could be used as signs of the zodiac. If the Greeks had bor- 

 rowed from another nation any tiling more than the idea and 

 number of the divisions (Dodecatomeria) of a zodiac — -if they 

 had borrowed the zodiac itself, with its signs — they v/ould 

 not at first have contented themselves with only eleven con- 

 stellations. The Scorpion would not have been divided into 

 two groups ; nor would zodiacal constellations have been in- 

 troduced (some of which, like Taurus, Leo, Pisces, and Virgo, 

 extend over a space of 35° to 48°, while others, as Cancer, 

 Aries, and Capicornus, occupy only from 19° to 23°), which 

 are inconveniently grouped to the north and south of the 

 ecliptic, either at great distances from each other, or, like Tau- 

 rus and Aries, Aquarius and Capricornus, so closely crowded 

 together as almost to encroach on each other. These cir- 

 cumstances prove that catasterisms previously formed were 

 converted into signs of the zodiac. 



The sign of Libra, according to Letronne's conjecture, was 

 introduced at the time of, and perhaps by, Hipparehus. It 

 is never mentioned by Eudoxus, Archimedes, Autolycus, or 

 even by Hipparehus in the few fragments of liis writings 

 which have been transmitted to us (excepting indeed in one 



* Letroune, Orig. du Zod., p. 25 ; and Analyse Crit. des Repris. 

 Zod., 1846, p. 15. IJeler and Lepsius also consider it probable " that 

 the knowledge of the Chaldean zodiac, as well in reference to its divi- 

 sions as to the names of the latter, had reached the Greeks in the sev- 

 enth century before our era, although the adoption of the separate signs 

 of the zodiac in Greek astronomical literature was gradual and of a sub- 

 sequent date." (Lepsius, Chrcnologie der u^gypter, 1849, s. 65 and 

 124.) Ideler is inclined to believe that the Orientals had names^ but 

 not constellations for the Dodecatomeria, and Lepsius regards it as a 

 natural assumption " that the Greeks, at the period when their sphere 

 was for the most part unfilled, should have added to their own the 

 Chaldean constellations, from which the twelve divisions were named." 

 But are we not led on this supposition to inquire why the Greeks had 

 at first only eleven signs instead of introducing all the twelve belong- 

 ing to the Chaldean Dodecatomeria ? If they introduced the twelve 

 eigns, they ai'e hardly likely to hav6 removed one in order to replace i\ 

 at a subseq eu* period 



