143 COSMOS. 



number of fixed stars in the Hipparcho-Ptolemaic Catalogue, 

 Almagest, ed. Halma, t. ii. p. 83, (namely, for the 1st mag., 15 

 stars; 2nd, 45; 3rd, 208; 4th, 474; 5th, 217; 6th, 49,) with 

 the numbers of Argelander as already given, we find, as might 

 be expected, a great paucity of stars of the 5th and 6th magni- 

 tudes, and also an extraordinarily large number of those belong- 

 ing to the 3rd and 4th. The vagueness in the determinations 

 of the intensity of light in ancient and modern times renders 

 direct comparisons of magnitude extremely uncertain. 



cated their positions in his catalogue, according to longitude 

 and latitude, as was done by Ptolemy, is wholly devoid of 

 probability and in direct variance with the Almagest, book vii. 

 cap. 4, where this reference to the ecliptic is noticed as some- 

 thing new, by which the knowledge of the motions of the 

 fixed stars round the pole of the ecliptic may be facilitated. 

 The table of stars with the longitudes attached, which Petrus 

 Victorias found in a Medicean Codex and published with the 

 life of Aratus at Florence in 1567, is indeed ascribed by him 

 to Hipparchus, but without any proof. It appears to be a 

 mere rescript of Ptolemy's catalogue from an old manuscript 

 of the Almagest, and does not give the latitudes. As Ptolemy 

 was imperfectly acquainted with the amount of the retrogres- 

 sion of the equinoctial and solstitial points (Almag., vii. c. 2, 

 p. 13, Halma), and assumed it about -$ too slow, the catalogue 

 which he determined for the beginning of the reign of Anto- 

 ninus (Ideler, op. cit. s. xxxiv.) indicates the positions of the 

 stars at a much earlier epoch (for the year 63 A. D.) (Regarding 

 the improvements for reducing stars to the time of Hippar- 

 chus, see the observations and tables as given by Encke in 

 Schumacher's Astron. Nackr.,no. 608, s. 113-126.) The earlier 

 epoch to which Ptolemy unconsciously reduced the stars in his 

 catalogue, corresponds tolerably well with the period to which 

 we may refer the Pseudo-Eratosthenian Catasterisms, which, as 

 I have already elsewhere observed, are more recent than the 

 time of Hyginus, who lived in the Augustine age, but appear 

 to be taken from him and have no connection with the poem 

 of Hermes by the true Eratosthenes. (Eratosthenica^ ed. 

 Bernhardy, 1822, pp. 114, 116, 129.) These Pseudo-Eratos- 

 thenian Catasterisms contain, moreover, scarcely 700 indi- 

 vidual stars distributed among the myth^-il constellations. 



