THE CONTINUITY OF SCIENCE 55 



afterwards constructed ; he advocated basing natural 

 science on experience and careful observation rather 

 than on a process of reasoning. Roger Bacon's writ- 

 ings are characterized by a philosophical breadth of 

 view. To his mind the earth is only an insignificant 

 dot in the center of the vast heavens. 



In the centuries that followed the death of Bacon 

 the relation of this planet to the heavenly bodies was 

 made an object of study by a succession of scientists 

 who like him were versed in the achievements of pre- 

 ceding ages. Peurbach (1423-1461), author of New 

 Tfieorics of the Planets, developed the trigonometry 

 of the Arabians, but died before fulfilling his plan 

 to give Europe an epitome of the astronomy of 

 Ptolemy. His pupil, Regiomontanus, however, more 

 than made good the intentions of his master. The 

 work of Peurbach had as commentator the first 

 teacher in astronomy of Copernicus (1473-1543). 

 Later Copernicus spent nine years in Italy, study- 

 ing at the universities and acquainting himself with 

 Ptolemaic and other ancient views concerning the 

 motions of the planets. He came to see that the ap- 

 parent revolution of the heavenly bodies about the 

 earth from east to west is really owing to the revolu- 

 tion of the earth on its axis from west to east. This 

 view was so contrary to prevailing beliefs that Co- 

 pernicus refused to publish his theory for thirty-six 

 years. A copy of his book, teaching that our earth is 

 not the center of the universe, was brought to him on 

 his deathbed, but he never opened it. 



Momentous as was this discovery, setting aside the 

 geocentric system which had held captive the best 

 minds for fourteen slow centuries and substituting the 



