i2 4 POPULAR SCIENCE MONTHLY. 



became a firm believer in the new heliocentric astronomy, which he was 

 well prepared to receive and to expound. 



A letter from Eheticus, written a few months after his arrival at 

 Frauenburg, affords one of the very few personal views of Copernicus 

 that have come down to us. The letter was published with a long 

 Latin title, in 1540, and is known as 'Narratio Prima.' "I beg you 

 to have this opinion concerning that learned man, my preceptor: that 

 he had been an ardent admirer and follower of Ptolemy; but when he 

 was compelled by phenomena and demonstration, he thought he did 

 well to aim at the same mark at which Ptolemy had aimed, though 

 with a bow and shafts of very different material from his. We must 

 recollect what Ptolemy has said : ' He who is to follow philosophy must 

 be a freeman in mind. ' " " My preceptor was very far from rejecting 

 the opinions of ancient philosophers from love of novelty, and except 

 for weighty reasons and irresistible facts. His years, his gravity of 

 character, his excellent learning, his magnanimity and nobleness of 

 spirit are very far from any such temper (of disrespect to the an- 

 cients)." This letter, addressed by Eheticus to his old master 

 Schoner, was the first easily accessible account of the new theory. 

 The life-giving sun, he says, is placed in its appropriate place, and a 

 single motion of the earth explains all the planetary motions. All is 

 harmony as if they were bound together with a golden chain. He 

 praises the great simplicity and reasonableness of the new doctrine, as 

 well as the almost divine insight and the uncommon diligence of the 

 master. He had formerly no idea, he says, of the immense labor re- 

 quired in such works, and the example of Copernicus leaves him in 

 astonishment. Copernicus had made a complete collection of all known 

 astronomical observations, and by these his theory was tested. The 

 master was not content until every hypothesis had been fully proved. 



Eheticus showed his admiration for Copernicus not only in these 

 public, but also in private, ways. Books that he presented to the master 

 (which are often annotated by Copernicus 's own hand) are still to be 

 found in various libraries of Sweden, where they were taken after the 

 plundering of Ermcland in the thirty years' war. At Wittenburg 

 Eheticus and his colleague Eeinhold, Copernicans both, were by the 

 conditions of their professorships obliged to teach the Ptolemaic sys- 

 tem, just as Galileo, at Padua, a Copernican, had to confine himself 

 to the exposition of Sacrobosco. It may safely be surmised, however, 

 that their pupils did not leave them without hearing something of the 

 true doctrines. In the 'Narratio,' Eheticus, who was a firm believer 

 in astrology, uses the data of the 'De Eevolutionibus' as bases for wide- 

 reaching astrological predictions. They are of no interest in them- 

 selves, but as the letter was written under the eye of Copernicus, they 

 lead to the conclusion that they were not disapproved by the latter. 



