132 THE BORDERLAND OF SCIENCE. 



beings like men would perish, with the resulting cold. 

 And when, passing beyond Mars, and traversing the 

 wonderful ring of small planets, we come to Jupiter, 

 where, so far as direct solar heat is concerned, we are 

 assured that there is not a tithe of the supply which 

 would be necessary for beings like ourselves. For the 

 gap between Mars and Jupiter is quite unlike that 

 which separates Mars from the earth, and the earth 

 from Venus (referring of course to the paths of these 

 bodies). From Mars to Jupiter is fully six times the 

 distance from the earth to Mars, and the solar light 

 and heat at Jupiter are reduced to less than the ninth 

 part of the light and heat which are received by Mars. 

 Of course Saturn, Uranus, and Neptune are still less 

 fitted to be the abodes of creatures such as those which 

 inhabit the earth. 



Mars alone had given promise of habitability in the 

 ordinary sense of the term. And the study of Mars 

 had revealed many interesting results, apparently con- 

 firming in a striking manner the opinion that he is a 

 ' miniature of our earth ' a globe resembling the earth 

 in physical habitudes, and like her the abode of living 

 creatures, amongst which may be races resembling man. 

 We know that Mars is not so very much farther than 

 the earth from the sun, as at a first view to dispose of 

 all idea that he is inhabited. His year is not so much 

 longer than ours as to render our conceptions of his 

 seasons incompatible with the existence of vegetable 

 life resembling that which exists on the earth. Then we 

 know that his seasons resemble those of the earth in 



