COPERNICUS. 125 



So far as I know, this is the only evidence for the belief of Copernicus 

 in astrology. We have no horoscopes from his hand but, like all his 

 contemporaries, he probably gave it a place among the sciences. 



Eheticus deserves the gratitude of all calculators for his table of 

 trigonometric functions (sines, tangents, secants) to ten decimal places, 

 for every 10" of the quadrant, published in a huge volume by his 

 pupil, Otho, under the title 'Opus Palatinum de Triangulis.' The 

 tables of Eheticus are the basis upon which Vlacq founded his great 

 tables, and they have served as models for many followers. Lansberg's 

 tables appeared fifteen years after the ' Opus Palatinum ' and lightened 

 the immense labors of Kepler. 



Toward the end of the year 1541 Eheticus returned to Wittenberg 

 carrying with him a part of Copernicus 's manuscript — a treatise on 

 'Trigonometry' — which he printed in 1542. The complete manuscript 

 of the 'De Eevolutionibus' was sent by Copernicus to his old friend 

 Giese, the bishop of Culm, for such disposition as he thought best. 

 The bishop sent it to Eheticus to arrange for its printing at Nurem- 

 berg, and to see it through the press. It fell out that the printing 

 had to be confided to Andreas Osiander, a Lutheran minister interested 

 in astronomy. The book was published early in 1543, and a copy 

 reached Copernicus on May 24, the very day of his death. 



Osiander prefixed to the volume an introductory note which he did 

 not sign, as follows: 



Scholars will be surprised by the novelty of the hypothesis proposed in 

 this book, which supposes the earth to be in motion about the sun, itself fixed. 

 But if they will look closer they will see that the author is in no wise to be 

 blamed. The aim of astronomy is to observe the heavenly bodies and to dis- 

 cover the laws of their motions; the veritable causes of the motions it is 

 impossible to assign. It is consequently permissible to imagine causes, 

 arbitrarily, under the sole condition that they should represent, geometrically, 

 the state of the heavens, and it is not necessary that such hypotheses should 

 be true, or even probable. It is sufficient that they should furnish positions 

 that agree with observations. If astronomy admits principles, it is not for 

 the purpose of affirming their truth, but to give a certain basis for calculation. 



The best authorities affirm that Osiander 's apology, which he had sug- 

 gested to Copernicus as early as 1540, was unauthorized. 



Osiander made many changes in the text also, and added the last 

 two words of the title under which the book was printed — ' De Eevolu- 

 tionibus Orbium Ccelestium. ' Eeaders of our day universally interpret 

 the apology to be an attempt to forestall theological opposition and per- 

 secution. They remember the conflict of Galileo with the church. But 

 Osiander was a protestant divine, Copernicus a catholic priest. It is 

 passing strange to conceive that a Lutheran schismatic should inter- 

 vene to shield an orthodox catholic from accusations of heresy. More- 

 over, Copernicus had good reasons for believing that the princes of the 



