1 8 VESTIGES OF THE 



respective distances of the planets from the sun. It will 

 stand tlius — 



4 7 lo i6 28 52 100 196 



Mere. Venus. Earth. Mars. Jupiter. Saturn. Uranus. 



It will be observed that the first row of figures goes on 

 from the second on the left hand in a succession of du- 

 plications, or multiplications by tw^o. Surely there is 

 here a most surprising proof of the unity which I am 

 claiming for the solar system. It was remarked when 

 this curious relation was first detected, that there was a 

 want of a planet corresponding to 28 ; the difficulty was 

 afterw%ards considered as in a great measure overcome by 

 the discovery of four small planets revolving at nearly 

 one mean distance from the sun, between Mars and 

 Jupiter. The distances bear an equally interesting 

 mathematical relation to the times of the revolutions 

 round the sun. It has been found that, with respect to 

 any tw^o planets, the squares of the times of revolution 

 are to each other in the same proportion as the cubes of 

 their mean distances — a most surprising result, for the 

 discovery of which the world was indebted to the illustri- 

 ous Kepler. Sir John Ilerschel truly observes — ^'When 

 we contemplate the constituents of the planetary system 

 from the point of view which this relation affords us, it 

 is no lonirer mere analoixv which strikes us, no loncfer a 

 general resemblance among them, as individuals inde- 

 pendent of each other, and circulating about the sun, 

 each accoi'ding to its own peculiar nature, and connected 

 with it by its own peculiar tie. The resemblance is now 

 perceived to be a true famihj likeness ; they are bound 

 up in one chain — interwoven in one web of mutual 

 I'elation and harmonious agreement, subjected to one 

 pervading influence, which extends from the centre to 

 tlie farthest limits of that great system, of which all of 



