108 cosMoy. 



and who comments on his boldness in attempting, as it were, 

 " to leave heaven as a heritage to posterity," should have 

 enumerated only 1600 stars visible in the fine sky of Italy I-^' 

 In this enumeration he had, however, descended to stars of 

 the fifth, while half a century later Ptolemy indicated only 

 1025 stars doAvn to the sixth magnitude. 



Since it has ceased to be the custom to class the fixed stars 

 merely according to the constellations to which they belong, 

 and they have been catalogued according to determinations 

 of place, that is, in their relations to the great circles of the 

 equator or the ecliptic, the extension as well as the accuracy 

 of star catalogues has advanced with the progress of science 

 and the improved construction of instruments. No catalogues 

 of the stars compiled 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 sev- 

 enth book of the Almagest (cap. 3, p. xv., Halma), their ob- 

 servations were conducted in a very rough manner (^Trdvv 

 bXoaxspcog), there can be no doubt that they both determ- 

 ined the declination of many stars, and that these determin- 

 ations 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 sun^ey of the whole firmament, and endeavor 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 invented 

 tradition.! It does indeed seem remarkable that Ptolemy 

 should not refer to the circumstance, but yet it must be ad- 

 mitted that the sudden appearance of a brightly luminous 



* " Patrociiiatur vastitas ccbH, immeusa discreta aUitiidine, iu duo at- 

 que septuaginta sigua. Hsec sunt reriim et animantium effigies, in qiias 

 digessere coelum periti. In his quidem mille sexcentas adnotaverc Stel- 

 las, insignes videlicet effectuvisuve" .... Plin., ii., 41. "Hipparchus 

 nuncjuam satis laudatus, ut quo nemo magis approbaverit cognationern 

 cum homine siderum auimasque nostras partem esse coeli, novam si el 

 lam et aliam iu ojvo suo geuitam deprehendit, ejusque niotu, qua die 

 fulsit, ad dubitationem est adductus, anne hoc sa^pius fieret moveren- 

 turque et ese quas putamiis affixas ; itemque aiisus rem etiam Deo ini- 

 probam, adnumerare posteris Stellas ac sidei'a ad nomeu expungere, or- 

 ganis excogitatis, per qivee singulai'um loca atque magnitudines signaret, 

 ut facile discerni posset ex eo, won mode au obireut nascerenturve, sed 

 an omnino aliqna transirent moverenturve, item an crescerent niiinic- 

 renturque, coelo in hereditate cunctis relicto, si quisquam qi" cretionem 

 earn caperet inventus esset." — Plin., ii,, 26. 



t Delambre, Hist, de V Astr. Anc, torn, i., p. 290, and Hist, de VAstr 

 Mod., torn, ii., p. 186. 



