1 3rs COSMOS. 



In the catalogue of the Almagest, Achernar, a star of the 

 first magnitude, the last in Eridanus (Achir el-nahr, in 

 Arabic), is also given, although it was 9^ below the hori- 

 zon. A report of the existence of this star must therefore 

 have reached Ptolemy through the medium of those who had 

 made voyages to the southern parts of the Red Sea, or be- 

 tween Ocelis and the Malabar emporium, Muziris.* Though 

 improvements in the art of navigation led Diego Cam, to- 

 gether with Martin Behaim, along the western coasts of Af- 

 rica, as early as 1484, and carried Bartholomew Diaz in 

 1487, and G-ama in 1497 (on his way to the East Indies), 

 far beyond the equator, into the Antarctic Seas, as far as 

 35° south lat., the first special notice of the large stars and 

 nebulous spots, the first description of the " Magellanic 

 clouds" and the "coal-sacks," and even the fame of " the 

 wonders of the heavens not seen in the Mediterranean," be- 

 long to the epoch of Vicente Yaiiez Pinzon, Amerigo Ves- 

 pucci, and Andrea Corsali, between 1500 and 1515. The 

 distances of the stars of the southern hemisphere Avere meas- 

 ured at the close of the sixteenth and the beginning of the 

 seventeenth century. f 



Laws of relative density in the distribution of the fixed 

 stars in the vault of heaven first began to be recognized 

 w^hen Sir William Herschel, in the year 1785, conceived 

 the happy idea of counting the number of stars which passed 



starred southern hemisphere." (A. W. von Schlegel, in the Zeitschrift 

 fur die Kunde des Morgenlandes, bd. i., s. 240.) While this Indian 

 myth figuratively depicts the astonishment excited in wandering na- 

 tions by the aspect of a new heaven (as the celebrated Spanish poet, 

 Garcilaso de la Vega, says of travelers, " they change at once their coun- 

 try and stars," mudan de pays y de estrellas), we are powerfully re- 

 minded of the impression that must have been excited, even in the 

 rudest nations, when, at a certain part of the earth's surface, they ob- 

 served large, hitherto unseen stars appear in the honzon, as those in 

 the feet of the Centaur, in the Southern Cross, in Eridanus or in Argo, 

 while those with which they had been long familiar at home wholly 

 disappeared. The fixed stars advance toward us, and again recede, 

 owing to the precession of the equinoxes. We have aa-eady mentioned 

 that the Southern Cross was 7° above the horizon, in the countries 

 ai'ound the Baltic, 2900 years before our era; at a time, therefore, when 

 the great pyramids had already existed five hundred years. (Compare 

 Cosmos, vol. i., p. 149, and vol. ii., p. 282.) " Canopus, on the other 

 hand, can never have been visible at Berlin, as its distance from the 

 south pole of the ecliptic amounts to only 14°. It would have required 

 a distance of 1° more to bring it within the limits of visibility for our 

 horizon." * Cosmos, vol. ii., p. 571, 572. 



t Olbers, in Schumacher's Jahrb. filr 1840, s. 249, and Cosmos, vol. i., 

 p. 51. 



