COMETS. 559 



Analogous fluctuations between cosmical and terrestrial hypo- 

 theses, between universal space and the atmosphere, still lead 

 at last to a more correct view of natural phenomena. 



Chaldean school of astrologers, as well as among the Pytha- 

 goreans, and, properly speaking, among all ancient schools. 

 Seneca (Nat. Qucest. vii. 3) quotes the antagonistic evidence 

 of Apollonius Myndius and Epigones. The latter is seldom 

 mentioned, yet Plinius (vii. 57.) represents him as " gravis 

 auctor in primis," as does also, without praise, Censorius 

 de die natali, cap. xvii. and Stob. Eel. Pliys. i. 29, p. 586, ed. 

 Heeren. (Compare Lobeck, Aglaopli. xi.) Diodorus (xv. 50) 

 believes that the universal and prevailing opinion among the 

 Babylonian astrologers (the Chaldeans), was that the comets 

 reappeared at definite times in their certain orbits. The 

 division which prevailed between the Pythagoreans, as to the 

 planetary nature of the comets, and which is mentioned by 

 Aristotle (Meteorol. lib. i. cap. vi. 1,) and Pseudo- Plutarch 

 (de Plac. Philos. lib. iii. cap. ii.), extended, according to the 

 former (Meteorol. i. 8, 2), also to the nature of the Milky Way, 

 the forsaken course of the Sun, or of the overthrown Phaeton. 

 (Compare also Letronne, in the Mem. de V Acad. des Inscrip- 

 tions. 1839, torn. xii. p. 108.) By some of the Pythagoreans 

 the opinion of Aristotle was advanced, " that the comets be- 

 longed to the number of those planets which, like Mercury, 

 only became visible after a long time when rising in the 

 course above the horizon." In the extremely fragmentary 

 Pseudo-Plutarch it is said, that they " ascend at definite 

 times after a complete revolution." A great deal of matter 

 contained in separate works, referring to the nature of the 

 comets, has been lost to us, that of Arrian, which StobEeus 

 employed; of Charimander, whose mere name has been 

 retained only by Seneca and Pappus. Stobaeus brings forward, 

 as the opinion of the Chaldeans (Eclog. lib. i. cap. xxv. p. 61, 

 Cfirist. Plantinusj) that the reason the comets remain so seldom 

 visible to us, is because they hide themselves in the depth* 

 of the ether (of space), like the fish in the depths of the 

 ocean. The most graceful, and in spite of its rhetorical 

 colouring, the best founded opinion of antiquity, and the 

 one corresponding most closely with present views, is that of 

 Seneca. In the Nat. Qucest. i : ! vii. cap. xxii. xxv. andxxxi. 



