UirriO GLOBI INTELLECTUALIS 303 



etiam ex sententia Tychonis planetas reliquos ; adoo ut 



plane vi.leatur sol centri naturam sustinere posse, et 



re in aliquibus; eo propius abest, ut universi 



centrum r.mstitui }>ossit ; qua? Copernici assertio fuit. 



Yenintamen in svstemate Copernici multa et magna 



inveniuntur incommoda ; nam et quod triplici motu ter- 



'iieravit, 1 incommodum magnum, et quod solem a 



. often called the Egyptian. See with respect to it Martin, 

 "1. ii. p. 129. According to Gassendi, Copernicus was much 

 struck l>y the passage of Martianus Capella in which this system is men- 

 tioned, remarked that the Copernican system includes two dis- 

 tinct ek'inei.t-: the tirst the reference of the motion of the planets to the 

 sun as a common centre; the second the doctrine of the motion of the earth. 

 The first was common to Copernicus with Tycho Brahe; the second was 

 his own exclusivt Stunirvcho's system, as Apelt well observes, is the 

 natural transition'''!''"'"/ ' .'u/ltctinnn in, the Copernican, and must of neces- 

 sity have l>-en arrived' at as soon as the true distances between the sun 

 and the planets were introduced into the Ptolemaic hypothesis. Thus 

 in is a step backwards, although it saved the phenomena as 

 well as that of Copernicus: but, as Apelt goes on to remark, Tycho was an 

 -. and Copernicus a philosopher, who sought not merely for an astro- 

 liut for a new idea of the universe. Copernicus says 

 of himself, that he had set the sun, the great light of the universe, in the 

 the temple of nature, and as on a kingly throne. No man less 

 deserved to be spoken of as a merely calculating astronomer. Bacon's dif- 

 ficulty. that in the Copernican system the moon revolves about the earth, 

 had been felt by others. Galileo, at the end of the Sydereus Nuncius, 

 points out the analogy of this hypothesis with what he had discovered to 

 be the case with respect to Jupiter and his satellites remarking that it re- 

 moved the difficulty in question. 



1 Copernicus conceived the earth's motion round the sun to be as if the 



earth were rigidly attached to the line which joins them. Thus the motion 



round the sun results from the composition of two simpler motions, namely 



that of the earth's centre and the change of the direction of its axis. The 



M components is eliminated from the hypothesis by supposing 



s the motion round the sun and about its own axis, has 



a third motion, namely a change in the direction of its axis equal and op- 



that which results from the motion round the sun. Galileo showed, 



by an illustrative experiment, that this kind of motion was in reality only an 



mpliVatioii: and Gilbert also makes the same remark. "See 



4., and the Physiol. Nova. In Germany the same thing 



*us rein thman; but I am not aware whether he or Gilbert was 



the first person to introduce the simplification, which is indeed obvious. 



