312 cosmos. 



Among all the opinions of the ancients, those which appeared 

 to exercise the greatest influence on the direction and gradual 

 development of the ideas of Copernicus are expressed, accord- 

 ing to Gassendi, in a passage in the encyclopsedic work of Mar- 

 tianus Mineus Capella, written in a half-barbarous language, 

 and in the System of the World of Apollonius of Perga. Ac- 

 cording to the opinions described by Martianus Mineus of 

 Madaura, and which have been very confidently ascribed, 

 sometimes to the Egyptians, and sometimes to the Chaldeans,* 



* See the profound treatment of this subject in Martin, Etudes sur 

 Timie, t. ii., p. Ill, Cosmographie des Egyptiens), and p. 129-133) An- 

 tice - dents du Systeme de Copernic). The assertion of this learned phi 

 lologist, that the original system of Pythagoras differed from that of 

 Pnilolaiis,and that it regarded the earth as fixed in the center of the 

 universe, does not appear to me to be entirely conclusive (t. ii., p. 103 

 and 107). I would here explain myself more fully respecting the re- 

 markable statement of Gassendi regarding the similarity of the systems 

 of Tycho Brahe and Apollonius of Perga, to which I have referred in 

 the text. We find the following passage in Gassendi's biographies : 

 " Magnam imprimis rationem habuit Copernicus duarum opinionum 

 affiuium, quarum unam Martiano Capella?, alteram Apollonio Pergaco 

 attribuit. Apollonius solem delegit, circa quem, ut centrum, non modo 

 Mercurius et Venus, verum etiam Mars, Jupiter, Saturnus suas obirent 

 periodos, dum Sol interim, uti et Luna, circa Terrum, ut circa centrum, 

 quod foret Aifixarum mundique centrum, moverentur ; quae deinceps 

 quoque opinio Tychonis propemodum fuit. Rationem autem magnam 

 harum opinionum Copernicus habuit, quod utraque eximie Mercurii ac 

 Veneris circuitiones repra?sentaret, eximieque causam retrogradatio- 

 num, directionum, stationuin in iis apparentium exprimeretet posterior 

 (Pergaei) quoque in tribus Planetis superioribus praestaret." (Gassendi, 

 Tychonis Brahei Vita, p. 296.) My friend the astronomer Galle, to 

 whom I applied for information, agrees with me in thinking that noth- 

 ing could justify Gassendi's decided statement. " In the passages," he 

 writes to me, " to which you refer in Ptolemy's Almagest (in the com- 

 mencement of book xii.), and in the works of Copernicus (lib. v., cap. 

 3, p. 141, a. ; cap. 35, p. 179, a. and b. ; cap. 36, p. 181, b.), the only 

 questions considered are the retrogressions and stationary conditions of 

 the planets, in which Apollonius's assumption of their revolution round 

 the sun is indeed referred to (and Copernicus himself mentions express- 

 ly the assumption of the earth's standing still), but it can not be de- 

 termined when he became acquainted with what he supposes to have 

 been derived from Apollonius. We* can only, therefore, conjecture that 

 he assumed, on some later authority, that Apollonius of Perga had con- 

 structed a system similar to that of Tycho, although I do not find, even 

 iii Copernicus, any clear exposition of such a system, or any reference 

 to ancient passages in which it may be spoken of. If lib. xii. of the 

 Almagest should be the only source from whence the complete Tycho- 

 nic view is ascribed to Apollonius, we may consider that Gassendi has 

 gone too far in his suppositions, and that the case is precisely the same 

 as that of the phases of Mercury and Venus, of which Copernicus spoke 

 (lib. i., cap. 10, p. 7, b., and 8, a.), without decidedly applying them to 

 his system. Apollonius may, perhaps, in a similar manner, have treat 



