A GIANT PLANET. 109 



We should be led by the theory here maintained to 

 regard the major planets which travel outside the zone 

 of asteroids as in a sense secondary suns. So viewed, 

 they could not be regarded as orbs fit for the support 

 of living creatures. Yet, as each of them is the 

 centre of a scheme of dependent worlds, of dimensions 

 large enough to supply room for many millions of 

 living creatures, we should not merely find a raison 

 d'etre for the outer planets, but we should be far better 

 able to explain their purpose in the scheme of creation 

 than on any theory hitherto put forward respecting 

 them. Jupiter as an abode of life is a source of 

 wonder and perplexity, and his satellites seem scarcely 

 to serve any useful purpose. He appears as a bleak 

 and desolate dwelling-place, and they together supply 

 him with scarcely a twentieth part of the light which 

 we receive from our moon at full. But regarding 

 Jupiter as a miniature sun, not indeed possessing any 

 large degree of inherent lustre, but emitting a con- 

 siderable quantity of heat, we recognize in him the 

 fitting ruler of a scheme of subordinate orbs, whose 

 inhabitants would require the heat which he affords to 

 eke out the small supply which they receive directly 

 from the sun. The Saturnian system, again, is no 

 longer mysterious when thus viewed. The strange 

 problem presented by the rings, which actually conceal 

 the sun from immense regions of the planet for years 

 together in the very heart of the winter of those 

 regions, is satisfactorily solved when the Saturnian 

 satellites are regarded as the abodes of life, and Saturn 



