gS A Short History of Astronomy [CH. IV. 



74. Similar requests must have been made by others, but 

 his final decision to publish his ideas seems to have been 

 due to the arrival at Frauenburg in 1539 of the enthusiastic 

 young astronomer generally known as Rheticus.* Born in 

 1514, he studied astronomy under Schoner at Niirnberg, 

 and was appointed in 1536 to one of the chairs of 

 mathematics created by the influence of Melanchthon at 

 Wittenberg, at that time the chief Protestant University. 



Having heard> probably through the Commentariolus, of 

 Coppernicus and his doctrines, he was so much interested 

 in them that he decided to visit the great astronomer at 

 Frauenburg. Coppernicus received him with extreme 

 kindness, and the visit, which was originally intended to 

 last a few days or weeks, extended over nearly two years. 

 Rheticus set to work to study Coppernicus's manuscript, 

 and wrote within a few weeks of his arrival an extremely 

 interesting and valuable account of it, known as the First 

 Narrative (Prima Narratio\ in the form of an open letter 

 to his old master Schoner, a letter which was printed in the 

 following spring and was the first easily accessible account 

 of the new doctrines.f 



When Rheticus returned to Wittenberg, towards the end 

 of 1541, he took with him a copy of a purely mathematical 

 section of the great book, and had it printed as a textbook 

 of the subject (Trigonometry) ; it had probably been already 

 settled that he was to superintend the printing of the com- 

 plete book itself. Coppernicus, who was now an old man 

 and would naturally feel that his end was approaching, sent 

 the manuscript to his friend Giese, Bishop of Kulm, to do 

 what he pleased with. Giese sent it at once to Rheticus, 

 who made arrangements for having it printed at Niirnberg. 

 Unfortunately Rheticus was not able to see it all through 

 the press, and the work had to be entrusted to Osiander, 

 a Lutheran preacher interested in astronomy. Osiander 



* His real name was Georg Joachim, that by which he is known 

 having been made up by himself from the Latin name of the district 

 where he was born (Rhsetia). 



f The Commcntariolus and the Prima Narratio give most readers 

 a better idea of what Coppernicus did than his larger book, in which 

 it is comparatively difficult to disentangle his leading ideas from the 

 mass of calculations based on them. 



