NEW CONCEPTIONS IN SCIENCE 



I but a fulcrum whereon to rest, I could move the 

 earth." 



It is worth noting that here, and throughout his 

 writings, Archimedes proceeds entirely from the as- 

 sumption that the earth is a ball, and he mentions 

 the attempts that had been made to measure its 

 exact size ; he alludes, too, to the astronomical sys- 

 tem which we call Copernican that the sun, not 

 the earth, is the centre of things although he 

 died 1750 years before Nicholas Copernik's book 

 appeared. 



Now here is a strange thing. Not only did Ar- 

 chimedes possess the modern solar theory in its 

 general outlines, but he had in his hand the means 

 of proving or disproving its truth. The story of the 

 burning-mirrors, by which he destroyed the fleets 

 of Rome sent to take Syracuse, has been doubted 

 by some. But it is not the type of a story which 

 comes naturally from pure invention. Moreover, 

 Buff on showed that mirrors could be devised which 

 would burn objects at a considerable distance. And 

 we know that the galleys of Roman times were 

 small compared with our great ships of war; they 

 were of wood, and they came quite close to the 

 walls of the city. 



The burning -mirror depends upon exactly the 

 same principle as the reflecting telescope that is, 

 the reflection of the rays of light and heat in straight 



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