MAGELLANIC CLOUDS. 341 



and the long duration of Magellan's circumnavigation (from 

 August, 1519, to September, 1522), and the long sojourn 

 of a numerous crew under the southern sky, obliterated the 

 remembrance of all earlier observations, and spread the name 

 of the Magellanic Clouds among all the seafaring nations of 

 the Mediterranean. 



We have thus shown by a single example how the exten- 

 sion of the geographical horizon southward opened a new 

 field to contemplative astronomy. There were four ob- 

 jects.to which the attention of pilots was especially directed 

 in the new hemisphere, viz. the search for a southern polar 

 star, the form of the Southern Cross, which assumes a vertical 

 position when it passes through the meridian of the place of 

 observation, the Coal-sacks, and the circling clouds of light. 

 We learn from the treatise on the art of navigation (Arte de 

 Navcgar, lib. v. cap. 11), by Pedro de Medina, which has been 

 translated into many languages, and first appeared in 1545, 

 that the meridian altitudes of the " Cruzero " were used as 

 early as the first half of the sixteenth century for the deter- 

 minations of latitude. Measurement soon succeeded the 

 merely contemplative observation* The first work on the 

 position of stars contiguous to the antarctic pole was based 

 on the distances of known stars of the Rudolphine Tables, as 

 calculated by Tycho Brahe. This work, as I have already 

 observed, 87 was composed by Petrus Theodori of Embden, 

 and Friedrich Houtman of Holland, who navigated the 

 Indian Seas about the year 1594. The results of their 

 measurements were speedily embodied in the Star- Catalogues 



like the luminous spots scattered in the Milky Way 

 throughout the arch of heaven within the breadth of that 

 space." 



67 Cosmos, vol. ii. p. 666; vol. iii. pp. 151, 187. 

 E2 



