146 COSMOS. 



construction of instruments. No catalogues of the stars com- 

 piled by Timocharis and Aristyllus (283, B.C.) have reached us ; 

 but although, as Hipparchus remarks in the fragment " on the 

 length of the year," cited in the seventh book of the Almagest 

 (cap. 3, p. xv. Halma,) their observations were conducted in 

 a very rough manner (iraw oXoo-^ep&is) there can be no doubt 

 that. they both determined the declination of many stars, and 

 that these determinations preceded, by nearly a century and 

 a half, the table of fixed stars compiled by Hipparchus. This 

 astronomer is said to have been incited by the phenomenon of 

 a new star to attempt a survey of the whole firmament, and 

 endeavour to determine the position of the stars ; but the truth 

 of this statement rests solely on Pliny's testimony, and has 

 often been regarded as the mere echo of a subsequently in- 

 vented tradition. 7 It does indeed seem remarkable that 

 Ptolemy should not refer to the circumstance, but yet it must 

 be admitted that the sudden appearance of a brightly luminous 

 star in Cassiopeia (November, 1572,) led Tycho Brahe to 

 compose his catalogue of the stars. According to an in- 

 genious conjecture of Sir John Herschel, 8 the star referred to 

 by Pliny may have been the new star which appeared in 

 Scorpio in the month of July of the year 134 before our era, 

 (as we learn from the Chinese Annals of the reign of Wou-ti, 

 of the Han dynasty.) Its appearance occurred exactly six 

 years before the epoch at which, according to Ideler's investi- 

 gations, Hipparchus compiled his catalogue of the stars. 

 Edward Biot, whose early death proved so great a loss to 

 science, found a record of this celestial phenomenon in 

 the celebrated collection of Ma-tuan-lin, which contains an 



7 Delambre, Hist, de VAstr. anc., torn. i. p. 290, and Hist, 

 de r Astr. mod,., torn. ii. p. 186. 



8 Outlines, 831 ; Edward Biot sur les Etoiles Extraordi- 

 naires observees en Chine, in the Connaissance des temps pour 

 1846. 



