ZONE OF PLANETS BETWEEN MAES AND JUPITEK. 81 



than the ninth, magnitude, while several are as small as 

 the tenth, and three or four scarcely, if ever, rise as high 

 as the tenth magnitude. The reason that Qlbers was not 

 more successful in his search was, that he employed a 

 telescope of too feeble power, and did not extend his ex- 

 amination beyond stars of the eighth magnitude. 



Some may conclude that the number of asteroids now 

 known is so great, that the discovery of additional ones 

 is a matter of no interest, and is unworthy the attention 

 of astronomers. We regard the question in a very dif- 

 ferent light. If only one planet had hitherto been dis- 

 covered between Mars and Jupiter, our idea of the sim- 

 plicity and perfection of the solar system would have 

 been satisfied, and there might have been found ingenious 

 minds attempting to prove by d priori reasoning that no 

 other planets could possibly exist, unless beyond the 

 limits of the orbit of Neptune. But our theory of the 

 solar system, although apparently simple, would not have 

 been the true theory. Every new discovery shows the 

 solar system to be more complex than we had supposed ; 

 and unless we prefer error (provided it has a show of 

 simplicity) to truth, when it appears to our view complex, 

 we shall value every new discovery in the solar system, 

 because it promises to conduct us nearer to the true 

 theory of the universe. Every new asteroid which is 

 discovered, is a new fact to be explained. It presents a 

 new test by which every theory is to be tried. If our 

 theory be false, it is probable that some of these facts may 

 be shown to be inconsistent with it. When the number 



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