DISCOVERIES IN THE CELESTIAL SPACES. 689 



attraction (appetentia quondam naturalis partibus indita] towards 

 the sun as the centre of the world (centrum mimdi,) and 

 which is inferred from the force of gravity in spherical bodies, 

 seems to have hoveied before the mind of this great man, as 

 is proved by a remarkable passage in the 9th chapter of the 

 1st Book De Revolutionibus* 



On considering the different stages of the development of 

 cosmical contemplation, we are able to trace from the earliest 

 ages faint indications and presentiments of the attraction of 

 masses, and of centrifugal forces. Jacobi, in his researches on 



randam mundi symmetriam ac certum harmonise nexum motus et mag- 

 nitudinis orbium : qualis alio modo reperiri non potest. (Nicol. Copern. 

 De Revol. Orbium Ccelestium, lib. i. cap. 10, p. 9 b.) In this passage, 

 which is not devoid of poetic grace and elevation of expression, we recog- 

 nise, as in all the works of the astronomers of the 17th century, traces of 

 long acquaintance with the beauties of classical antiquity. Copernicus 

 had in his mind Cic. Somn. Scip. c. 4; Plin. ii. 4; and Mercur. Tris- 

 meg., lib. v. (ed. Cracov, 1586,) pp. 195 and 201. The allusion to the 

 Electro, of Sophocles is obscure, as the sun is never anywhere expressly 

 termed " all-seeing," as in the Iliad and the Odyssey, and also in the 

 Choephorce of ^Eschylus, (v. 980,) which Copernicus would not probably 

 have called Electro,. According to Bockh's conjecture, the allusion is 

 to be ascribed to an imperfect recollection of verse 869 of the (Edipus 

 Coloneus of Sophocles. It very singularly happens that quite lately, in 

 an otherwise instructive memoir (Czynski, Kopernik et ses Travaux, 

 1847, p. 102), the Electro, of the tragedian is confounded with electric 

 currents. The passage of Copernicus, quoted above, is thus rendered : 

 " If we take the sun for the torch of the universe, for its spirit and its 

 guide if Trismegistes call it a God, and if Sophocles consider it to 

 be an electrical power which animates and contemplates all that is con- 

 tained in creation ." 



* Pluribus ergo existentibus centris, de centro quoque mundi non 

 temere quis dubitabit, an videlicet fuerit istud gravity tis terrenae, an 

 aliud. Equidem existimo, gravitatem non aliud esse, quam appeten- 

 tiam quandam naturalem partibus inditam a divina providentia officis 

 universorum, ut in unitatem integritatemque suam sese conferant in 

 formam globi coeuntes. Quam affectionem credibile est etiam Soli, 

 Lunse, caeterisque errantium fulgoribus inesse, ut ejus efficacia in ea qua 

 se reprresentant rotunditate permaneant, quaa nihilominus multis modifc 

 suos efficiunt circuitus. Si igitur et terra faciat alios, utpote secundum 

 centrum (mundi), necesse erit eos esse qui similiter extrinsecus in 



multis apparent, in quibus invenimus annuum circuitum. Ipse 



denique Sol medium mundi putabitur possidere, quae omnia ratio 

 ordinis, quo ilia sibi invicem succedunt, et mundi totius harmonia nos 

 docet, si modo rem ipsam ambobus (ut aiunt) oculis inspiciamus." 

 (Copern. De Revol. orb. coil, lib. i. cap. 9, p. 7, b.) 



2 Y 



