A HISTORY OF SCIENCE 



sistent outcome of the problem he had set him- 

 self. 



But it remains to notice the most interesting feature 

 of this document in which the calculation of the sand- 

 grains is contained. "It was known to me," says 

 Archimedes, "that most astronomers understand by 

 the expression ' world ' (universe) a ball of which the 

 centre is the middle point of the earth, and of which 

 the radius is a straight line between the centre of the 

 earth and the sun." Archimedes himself appears to 

 accept this opinion of the majority, it at least serves 

 as well as the contrary hypothesis for the purpose of 

 his calculation, but he goes on to say: "Aristar- 

 chus of Samos, in his writing against the astronomers, 

 seeks to establish the fact that the world is really very 

 different from this. He holds the opinion that the fixed 

 stars and the sun are immovable and that the earth re- 

 volves in a circular line about the sun, the sun being 

 at the centre of this circle." This remarkable bit of 

 testimony establishes beyond question the position 

 of Aristarchus of Samos as the Copernicus of antiquity. 

 We must make further inquiry as to the teachings of 

 the man who had gained such a remarkable insight 

 into the true system of the heavens. 



ARISTARCHUS OF SAMOS, THE COPERNICUS OF ANTIQUITY 



It appears that Aristarchus was a contemporary of 

 Archimedes, but the exact dates of his life are not 

 known. He was actively engaged in making astro- 

 nomical observations in Samos somewhat before the 

 middle of the third century B.C. ; in other words, just 

 at the time when the activities of the Alexandrian 



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