COSMIC PHILOSOPHY 



with the equatorial planes of their primaries ; the 

 inclinations of the planetary axes to their orbit- 

 planes ; the oblate figures of the planets ; their 

 velocities of rotation ; the directions in which 

 they revolve ; and the directions in which they 

 rotate. To this last clause the apparent obstacle 

 presented by the retrograde rotation of Uranus 

 (and possibly of Neptune also) is seen on closer 

 examination to be no real obstacle ; and the fact 

 that the exception occurs among the outermost 

 planets, just where we might expect it to occur, 

 if at all, is a powerful argument in favour of the 

 general theory. A like .powerful argument is 

 furnished by the existence of apparently con- 

 tinuous rings about Saturn, the planet upon 

 which the centrifugal force bears the highest ratio 

 to gravity. Still more convincing is the tes- 

 timony rendered by the distribution of satel- 

 lites, — a testimony well-nigh meeting all the 

 requirements of crucial proof. Irregular as are 

 the sizes of the planets on a superficial view, we 

 find beneath this apparent irregularity a marvel- 

 lous symmetry of disposition, the explanation of 

 which, though incomplete, is as far as it goes in 

 favour of the nebular hypothesis. The breaking 

 up of the zone of asteroids, though not fully 

 explained, is seen to have occurred in the only 

 part of the system where such an event, accord- 

 ing to the hypothesis, was likely to occur. And 

 finally the geologic or meteorologic phenomena 

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