56 



r.larvels of the Universe 



MARS AS A HOME FOR MEN 



BY E. WALTER MAUXDER, F.R.A.S. 



" When the earth had to be prepared for the habitation of man, a veil, as it were, of intermediate 

 being was spread between him and its darkness, in which were joined, in a subdued measure, the 

 stability and insensibility of the earth, and the passion and perishing of mankind. 



" But the hea\-ens, also, had to be prepared for his habitation. 



" Between their burning light, — their deep vacuity, and man, as between the earth's gloom of 

 iron substance and man, a veil had to be spread of intermediate being; — which should appease the 

 unendurable glory to the level of human feebleness, and sign the changeless motion of the heavens 

 with the semblance of human vicissitude. 



" Between the earth and man arose the leaf. Between the heaven and man came the cloud. 

 His life being partly as the falling leaf, and partly as the flying vapour."* 



This is a poetic definition of the conditions of habitability for a planet. But the scientific 

 definition, though expressed in very different language and making use of different terms, in essence 

 corresponds to it closely. 



The falling leaf and the flying vapour are the tokens of a habitable world ; habitable, that 

 is to say, in the onlv sense in which we can properly use the term, by beings resembling men in 

 their capacities of body and of mind. A world in which the bare rock stands naked to the sunlight, 

 with only dry air between, can be no fit home for organic life in any highly-developed form. 



* Ruskin, "Modern Painters." 



A rough idea of the relative sizes of the planet? nearest the Sun and— on. necessarily, a different scale — their relative distances 

 from it. The comparative sizes of Mars and our satellite, the Moon, should be noticed. 50 greatly do they differ from the 

 appearance of these bodies in the heavens 



