138 THE GREEK ASTRONOMY. 



tempted to do this by the interest which the mathematical spirit of 

 the Greeks gave to the earliest astronomical discoveries, when these 

 were the subjects of their reasonings ; but we must now proceed to 

 contemplate them engaged in a worthier employment, namely, in add- 

 ing to these discoveries. 



CHAPTER II. 



Prelude to the Inductive Epoch of Hipparchus. 



WITHOUT pretending that we have exhausted the consequences of 

 the elementary discoveries which we have enumerated, we now 

 proceed to consider the nature and circumstances of the next great 

 discovery which makes an Epoch in the history of Astronomy ; and 

 this we shall find to be the Theory of Epicycles and Eccentrics. Be- 

 fore, however, we relate the establishment of this theory, Ave must, 

 according to the general plan we have marked out, notice some of the 

 conjectures and attempts by which it was preceded, and the growing 

 acquaintance with facts, which made the want of such an explana- 

 tion felt. 



In the steps previously made in astronomical knowledge, no inge- 

 nuity had been required to devise the view which was adopted. The 

 motions of the stars and sun were most naturally and almost irresisti- 

 bly conceived as the results of motion in a revolving sphere ; the 

 indications of position which we obtain from different places on the 

 earth's surface, when clearly combined, obviously imply a globular 

 shape. In these cases, the first conjectures, the supposition of the 

 simplest form, of the most uniform motion, required no after-correc- 

 tion. But this manifest simplicity, this easy and obvious explanation, 

 did not apply to the movement of all the heavenly bodies. The 

 Planets, the " wandering stars," could not be so easily understood ; the 

 motion of each, as Cicero says, "undergoing very remarkable changes 

 in its course, going before and behind, quicker and slower, appearing 

 in the evening, but gradually lost there, and emerging again in the 

 morning.'" A continued attention to these stars would, however, 



i Cic. de Nat. D. lib. ii. p. 450. " Ea quas Saturni Stella dicitur, ^anwique a 

 Grsecis nominattir, quae a terra abest plurimum, xxx fere annis cursum suum con- 



