not only propounded the view that the earth revolves 

 both on its own axis and around the sun, but that ,he 

 correctly removed the great stumbling-block in the way 

 of this theory by adding that the distance of the fixed 

 stars was infinitely greater than the dimensions of the 

 earth's orbit. Even the world of philosophy was not 

 yet ready for this conception, and, so far from seeing 

 the reasonableness of the explanation, we find Ptolemy 

 arguing against the rotation of the earth on grounds 

 which careful observations of the phenomena around 

 him would have shown to be ill-founded. 



Physical science, if we can apply that term to an 

 unco-ordinated body of facts, was successfully culti- 

 vated from the earliest times. Something must have 

 been known of the properties of metals, and the art 

 of extracting them from their ores must have been 

 practiced, from the time that coins and medals were first 

 stamped. The properties of the most common com- 

 pounds were discovered by alchemists in their vain 

 search for the philosopher's stone, but no actual progress 

 worthy of the name rewarded the practitioners of the 

 black art. 



Perhaps the first approach to a correct method was 

 that of * Archimedes, who by much thinking worked 

 out the law of the lever, reached the conception of the 

 centre of gravity, and demonstrated the first principles 

 of hydrostatics. It is remarkable that he did . not 

 extend his researches into the phenomena of motion, 

 whether spontaneous or produced by force. The sta- 

 tionary condition of the human intellect is most strik- 

 ingly illustrated by the fact that not until the time of 

 Leonardo was any substantial advance made on his 



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