ALEXANDRIAN OR HELLENISTIC PERIOD 



tronomy from the stand-point of geography and poetry 

 Had he done so, perhaps he might have reflected, like 

 Aristarchus before him, that it seems absurd for our 

 earth to hold the giant sun in thraldom ; then perhaps 

 his imagination would have reached out to the helio- 

 centric doctrine, and the cobweb hypothesis of epi- 

 cycles, with that yet more intangible figment of the 

 perfect circle, might have been wiped away. 



But it was not to be. With Aristarchus the scien- 

 tific imagination had reached its highest flight; but 

 with Hipparchus it was beginning to settle back into 

 regions of foggier atmosphere and narrower horizons. 

 For what, after all, does it matter that Hipparchus 

 should go on to measure the precise length of the year 

 and the apparent size of the moon's disk ; that he should 

 make a chart of the heavens showing the place of 1080 

 stars; even that he should discover the precession 

 of the equinox; what, after all, is the significance of 

 these details as against the all-essential fact that the 

 greatest scientific authority of his century the one 

 truly heroic scientific figure of his epoch should have 

 lent all the forces of his commanding influence to the 

 old, false theory of cosmology, when the true theory 

 had been propounded and when he, perhaps, was the 

 only man in the world who might have substantiated 

 and vitalized that theory ? It is easy to overestimate 

 the influence of any single man, and, contrariwise, to 

 underestimate the power of the Zeitgeist. But when 

 we reflect that the doctrines of Hipparchus, as pro- 

 mulgated by Ptolemy, became, as it were, the last 

 word of astronomical science for both the Eastern and 

 Western worlds, and so continued after a thousand 



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