COSMIC PHILOSOPHY 



ity, being nearly fifty times greater than on the 

 earth, has at least eight moons, besides his three 

 unbroken (or partly broken) rings. Mr. Spen- 

 cer may well declare that this emphatic agree- 

 ment of observation with deduction is an un- 

 answerable argument in favour of the nebular 

 theory. Here, where the dynamic relations in- 

 volved are so simple that we have no difficulty 

 in tracing them, the significance of the result 

 is unmistakable. Where we are enabled thus 

 directly to put the question to Nature, there is 

 no ambiguity in her answer. 



In the quoit-shaped rings which girdle Sat- 

 urn, we have a curious vestige — upon the 

 significance of which Kant strongly insisted — 

 of the ancient history of our planetary system. 

 So great has been the centrifugal fierce upon 

 Saturn, due to his rapid rotation and small 

 specific gravity, that the detachment of rings 

 would seem to have gone on after the surface 

 of the planet had assumed the liquid state ; and 

 whether the rings thus formed be now continu- 

 ous, or (as is far more probable) discontinuous, 

 they have obvious-ly had a much better chance 

 of preserving their equilibrium than the ordi- 

 nary vaporous moon-forming rings. The dyna- 

 mics of the Saturnian system still present many 

 difficult questions ; but the fact that Saturn is 

 the one planet which is still girdled by rings 

 that are apparently continuous is a very pow- 

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