THE UNIVERSE. DISCOVERIES IN THE CELESTIAL SPACES. 303 



as much as 32 times in linear dimension), ( 46 ) sufficed to 

 penetrate into cosmical depths before unknown. The exact 

 knowledge of many heavenly bodies belonging to our solar 

 system, the unchanging laws according to which they re- 

 volve in their orbits, and the perfected insight into the true 

 structure of the universe, are the characteristics of the 

 epoch which we here attempt to describe. The results 

 which this age produced have denned the leading outlines of 

 the picture of nature or sketch of the Cosmos, and have added 

 an intelligent recognition of the contents of the celestial 

 spaces, at least in the well-understood arrangement of one 

 planetary group, to the earlier explored contents of terres- 

 trial space. Seeking to fix attention on general views, I 

 here name only the most important objects of the astrono- 

 mical labours of the 1 7th century ; and would point to their 

 influence in inciting at once to great and unexpected mathe- 

 matical discoveries, and to a more comprehensive and 

 grander contemplation of the material universe. 



I have already remarked, that the age of Columbus, Gama, 

 and Magellan, the age of nautical discoveries, coincided with 

 other great and deeply influential events, with the awaken- 

 ing of religious liberty of thought, with the development of 

 art, and with the promulgation of the Copernican system of 

 the universe. Nicholas Copernicus (in two still existing 

 letters he calls himself Kopernik) had already attained his 

 21st year, and had observed with the astronomer Albert 

 Brudzewski, at Cracow, when Columbus discovered America. 

 Hardly a year after the death of the great discoverer, Coper- 

 nicus having returned to Cracow from a six years' residence 

 at Padua, Bologna, and Rome, we find him occupied with an 

 entice revolution in the astronomical view of the universe. 



