A HISTORY OF SCIENCE 



First and foremost, there is the doctrine that the 

 earth is a sphere. Pythagoras is said to have been the 

 first advocate of this theory ; but, unfortunately, it is 

 reported also that Parmenides was its author. This 

 rivalship for the discovery of an important truth we 

 shall see repeated over and over in more recent times. 

 Could we know the whole truth, it would perhaps ap- 

 pear that the idea of the sphericity of the earth was 

 originated long before the time of the Greek philoso- 

 phers. But it must be admitted that there is no record 

 of any sort to give tangible support to such an assump- 

 tion. So far as we can ascertain, no Egyptian or 

 Babylonian astronomer ever grasped the wonderful 

 conception that the earth is round. That the Italic 

 Greeks should have conceived that idea was perhaps 

 not so much because they were astronomers as because 

 they were practical geographers and geometers. Py- 

 thagoras, as we have noted, was born at Samos, and, 

 therefore, made a relatively long sea voyage in passing 

 to Italy. Now, as every one knows, the most simple 

 and tangible demonstration of the convexity of the 

 earth's surface is furnished by observation of an ap- 

 proaching ship at sea. On a clear day a keen eye may 

 discern the mast and sails rising gradually above the 

 horizon, to be followed in due course by the hull. 

 Similarly, on approaching the shore, high objects be- 

 come visible before those that lie nearer the water. 

 It is at least a plausible supposition that Pythagoras 

 may have made such observations as these during the 

 voyage in question, and that therein may lie the germ 

 of that wonderful conception of the world as a sphere. 



To what extent further proof, based on the fact that 



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