INDUCTIVE EPOCH OF HIPPARCHUS. 151 



Sect. 2. — Estimate of the Value of the Theory of Eccentrics and 



Epicycles. 



It may be useful here to explain the value of the theoretical step 

 which Hipparchus thus made ; and the more so, as there are, per- 

 haps, opinions in popular circulation, which might lead men to think 

 lightly of the merit of introducing or establishing the Doctrine of Epi- 

 cycles. For, in the first place, this doctrine is now acknowledged to 

 be false ; and some of the greatest men in the more modern history of 

 astronomy owe the brightest part of their fame to their having been 

 instrumental in overturning this hypothesis. And, moreover, in the 

 next place, the theory is not only false, but extremely perplexed and 

 entangled, so that it is usually looked upon as a mass of arbitrary and 

 absurd complication. Most persons are familiar with passages in 

 which it is thus spoken of. 10 



He his fabric of the heavens 



Hath left to their disprtes, perhaps to move 

 His laughter at their quaint opinions wide ; 

 Hereafter, when they come to model heaven 

 And calculate the stars, how will they wield 

 The mighty frame ! how build, unbuild, contrive. 

 To save appearances ! how gird the sphere 

 With centric and eccentric scribbled o'er, 

 Cycle in epicycle, orb in orb ! 



And every one will recollect the celebrated saying of Alphonso X., 

 king of Castile," when this complex system was explained to him; 

 that " if God had consulted him at the creation, the universe should 

 have been on a better and simpler plan." In addition to this, the sys- 

 tem is represented as involving an extravagant conception of the nature 

 of the orbs which it introduces ; that they are crystalline spheres, and 

 that the vast spaces which intervene between the celestial luminaries 

 are a solid mass, formed by the fitting together of many masses perpet- 

 ually in motion ; an imagination which is presumed to be incredible 

 and monstrous. 



We must endeavor to correct or remove these prejudices, not only 

 in order that we may do justice to the Hipparchian, or, as it is usually 

 called, Ptolemaic system of astronomy, and to its founder; but for an- 

 other reason, much more important to the purpose of this work; 



10 Paradise Lost, viii. » A. D. 1252. 



