258 THE STORY-BOOK OF SCIENCE 



in order to give light and heat to our planet; you 

 want thousands and thousands of other suns, quite 

 as large and immensely farther off in a word, the 

 stars to accomplish also, with velocities increasing 

 according to the distance, a daily journey around 

 this humble terrestrial globe! No! no! such an ar- 

 rangement is contrary to reason; to allow it is to 

 want to make the firebrands, the hearth, the whole 

 house, turn around a little bird on a spit." 



"Then it is the earth that turns, and we turn with 

 it," Claire again interposed. "In consequence of 

 this movement the sun and stars seem to us to move 

 in the opposite direction, like trees and houses when 

 we are on the train. Since the sun seems to go 

 around the earth from east to west in twenty-four 

 hours, it is a proof that the earth turns on its axis 

 from west to east in twenty-four hours." 



"The earth turns in front of the sun in a manner 

 to present its different parts successively to the rays 

 of that body; it pirouettes on its axis like a top. 

 Moreover, while it thus rotates in twenty-four hours, 

 it revolves around the sun in the interval of a year. 

 In playing with a top you find a good example of 

 two analogous movements executed together. When 

 the top turns on its point, not moving from the same 

 place in short, when it sleeps it has only the move- 

 ment of rotation. But in throwing it in a certain 

 way, you know better than I that it circles on the 

 ground while turning on its point. In that instance, 

 it represents in a small way the double movement of 

 the earth. Its rotation on its point represents the 

 whirling motion of the earth on its axis ; its course 



