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 THE NEW PLANETS. 205 



THE O PLANETS. 



AT a very early period of astronomical inquiry it was observed that the 

 spaces which intervene in the solar system between planet and planet aug- 

 ment in a double proportion as the planets recede from the sun. Thus the 

 space between Mercury and Venus is only half that which intervenes between 

 Venus and the earth. The latter, again, is only half that which separates this 

 planet from Mars. In like manner, the space between Jupiter and Saturn is 

 only half the space between Saturn and Herschel. To this remarkable law, 

 however, a conspicuous exception was noticed by Kepler, and was more em- 

 phatically insisted upon and more strictly demonstrated in the latter part 

 of the last century, by Bode of Berlin. While the spaces which successively 

 intervene between the planets Mercury, Venus, the earth, and Mars, are con- 

 tinually in the proportion of one to two, that which intervenes between Mars 

 and Jupiter, instead of being as it ought to be, in accordance with the law thus 

 indicated double the space between Mars and the earth is, in fact, nearly 

 six times that space. A planet, therefore, which would move between Mars 

 and Jupiter, at a distance beyond Mars equal to twice the distance of Mars 

 from the earth, would complete the system ; for then there would be between 

 such a planet and Jupiter twice the space which would intervene between it 

 and Mars. The presence of such a planet would then remove all exception in 

 the system to this law of increasing distance. Professor Bode ventured to 

 predict that a planet would at some future period be discovered revolving in 

 that position ; and even if no such planet were discovered, he maintained that 

 we should be justified in the inference that, at some former epoch, a planet did 

 exist in such a position. 



There is an instinctive faith in the harmony and universality of nature's 

 laws ; and when we behold in any of them a glaring exception, we are led at 

 once to anticipate that such exception is only apparent, and that by increased 

 knowledge we shall discover that the law is in reality universal. 



This remarkable prediction, as may be easily imagined, attracted the atten- 

 tion of astronomers to those quarters of the firmament where the suspected ( 



