112 COSMOS. 



and not visible in 39 52' lat. (?) It contains only 1019 

 positions of stars, which are reduced to the year 1437. A 

 subsequent commentary gives 300 other stars, observed by 

 Abu-Bekri Altizini in 1533. Thus we pass from Arabs, Per- 

 sians, and Moguls, to the great epoch of Copernicus, and 

 nearly to that of Tycho Brahe. 



The extension of navigation in the tropical seas, and in 

 high southern latitudes, has, since the beginning of the six- 

 teenth century, exerted a powerful influence on the gradual 

 extension of our knowledge of the firmament, though in a 

 less degree than that effected a century later by the appli- 

 cation of the telescope. Both were the means of revealing 

 new and unknown regions of space. I have already, in other 

 works, considered* the reports circulated first by Americus 

 Vespucius, then by Magellan, and Pigafetta (the companion 

 of Magellan and Elcano), concerning the splendor of the 

 southern sky, and the descriptions given by Vicente Yanez 

 Pinzon and Acosta of the black patches (coal-sacks), and by 

 Anghiera and Andrea Corsali of the Magellanic clouds. A 

 merely sensuous contemplation of the aspect of the heavens 

 here also preceded measuring astronomy. The richness of 

 the firmament near the southern pole, which, as is well 

 known, is, on the contrary, peculiarly deficient in stars, was 

 so much exaggerated that the intelligent Polyhistor Cardanus 

 indicated in this region 10,000 bright stars which were said 

 to have been seen by Vespucius with the naked eye.f 



Friedrich Houtman and Petrus Theodori of Embden (who, 

 according to Olbers, is the same person as Dircksz Keyser) 

 now first appeared as zealous observers. They measured 

 distances of stars at Java and Sumatra ; and at this period 

 the most southern stars were first marked upon the celestial 

 maps of Bartsch, Hondius, and Bayer, and by Kepler's in- 

 dustry were inserted in Tycho Brahe' s Rudolphine tables. 



Scarcely half a century had elapsed from the time of Ma- 

 gellan's circumnavigation of the globe before Tycho com- 

 menced his admirable observations on the positions of the 

 fixed stars, which far exceeded in exactness all that had 

 hitherto been done in practical astronomy, not excepting even 



about 19' in determining the latitude of Bokhara. (Humboldt, Asie 

 Centrale, t. iii., p. 592, and Sedillot, in the Prottgomenes d'Oloug-Beg, 

 p. exxiii.-exxv.) 



* Cosmos, vol. ii., p. 285-29C ; Humboldt, Examen Crit. de VHisloirt 

 de la Giogr., t. iv., p. 321-336 : t. v., p. 226-238. 



t Cardani Paralipomenon, lib. viii., cap. 10. (Opp., t. ix., ed. Lugd . 

 1663, p. 508.) 



