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 encyclopaedic work of Mar- 

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

 and in the System of the World of ApoUonius 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 Egyptieiis), and p. 129-133) An- 

 Uc6dents dn Systeme de Copernic). The assertion of this learnecf phi 

 lologist, that the original system of Pythagoras differed fi-om that of 

 Philolatis, 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). 1 would here exphiin myself more fully respecting the re- 

 markable statement of Gassendi regarding the similarity of the systems 

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

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

 " Magnam imprimis rationem habuit Copernicus duarum opinionum 

 affiuium, quarum unam Martiano Capelhe, alteram Apollonio Pergaco 

 attribuit. ApoUonius solem delegit, circa quem, ut centrum, non mode 

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

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

 quod foret Affixarum mundique centrum, movereutur ; quae deinceps 

 quoque opinio Tychouis propemodum fuit. Rationem autem magnam 

 hanrm opinionum Copernicus habuit, quod utraque eximie Mercurii ac 

 Veneris circuitiones repra.sentaret, eximieque causam retrogradatio- 

 oum, directionum, statiouum in iis apparentium exprimeretet posterior 

 (PergcBi) quoque in tribus Planetis superioribus pruestaret." (Gassendi, 

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

 vvhom I api)lied for information, agrees with me in thinking that noth 

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

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

 meucemeut 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 ApoUonius'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 ApoUonius. We can only, therefore, conjecture that 

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

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

 hi 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 

 A.lmagest should be the only source from whence the complete Tycho- 

 nic view is ascribed to ApoUonius, 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. ApoUonius may, perhaps, in a similar manner, have treat 



