13© POPULAR SCIENCE MONTHLY. 



lie troubla sa vie; (ou ne lui connait meme pas de commerce affectueux et in- 

 time* ) ; ennemi des discours inutiles, il ne rechercha ni les eloges ni le 

 bruit de la gloire; independant sans orgueil, content de son sort et content de 

 lui-nieme, il fut grand sans eclat, et, ne se revelant qu'a petit nombre de dis- 

 ciples choisis, il a accompli une revolution dans la science (sans que, se son 

 vivant, FEurope en ait rien su).f 



The system of Copernicus belongs to him alone. It is not the system 

 of Philolaus or of Aristarclms . . . but his own. His name is justly 

 attached to it on account of the care with which he explained its every 

 part, brought out all its phenomena, discovered the causes of these pre- 

 cessional movements which had been known for eighteen hundred years, 

 and explained only by the hypothetical existence of an eighth sphere 

 which made a revolution in 36,000 years around the axis of the ecliptic, 

 while, at the same time, it was constrained to turn daily about the axis 

 of the equator to account for the rising and setting of the stars. It is 

 then Copernicus who really introduced the motion of the earth into 

 astronomy, not merely into academic disputations; it is he who demon- 

 strated how the revolution of the earth about the sun explained the suc- 

 cession of the seasons and the precession of the equinoxes ; it is he who 

 showed how simply the retrogradations of the planets are explained by 

 the unequal velocity with which they traverse their concentric orbits 

 about the sun ; it is he who put astronomy on new foundations and who 

 opened the way for all later researches. It is to Kepler's enthusiasm 

 over the new truths that we owe the discovery of the true shape of the 

 planetary orbits, and the laws of their motion. The idea of the motion 

 of the earth was unfruitful among the ancients because it was never 

 entertained with seriousness. Its adoption by Copernicus is the begin- 

 ning of modern astronomy. (Delambre). 



The mountain peaks that cluster closely round the Lick Observatory 

 in California are of different heights and were unnamed when the 

 corps of observing astronomers took possession of the newly established 

 station. Names were assigned to them in the order of their heights 

 — Copernicus, Galileo, Kepler, Tycho and Ptolemy. One of the staff 

 of observers, who greatly distinguished himself during his short career 

 at the observatory, objected to the assignment of the name of Coper- 

 nicus to the highest peak. Copernicus was, no doubt, a great astron- 

 omer, he said, but was he preeminent? Should not the highest peak 

 have been assigned to another? The objection is answered the moment 

 the relation of Copernicus to the whole thought of the world is com- 

 prehended. His skill as a mere observer, his power as a mere geometer, 

 is not in question. His place is not to be assigned by narrow criteria 



* His relations with his uncle and with Giese were both affectionate and 

 intimate; those with the young Rheticus were ideal, considering their ages. 



t From the year 1514 onwards his name was widely known among the 

 circles of the learned, and his theories were circulated as early as 1530. 



