MARS IN HIS ICY CUIRASS 97 



Upon this foundation of observed phenomena, Prof. 

 Lowell has built up his original and startling theory of 

 life on Mars. And here is the gist of it : 



1. The distance of Mars from the sun, its source of 

 heat, is not so great, he argues, as absolutely to pre- 

 clude the existence of animal life. Mars' summer is 

 much longer than ours, and planetary life is determined 

 rather by the mildness of summer than by the asperity 

 of winter. Mars' mean temperature he estimates to be 

 about 48 F. 



2. Water is essential to life. There being no 

 oceans, as he says, the streams too must be dried up. 

 The alternative is presented of death from thirst, or of 

 recourse to the only fresh water supply remaining, to 

 wit, the polar snows. 



3. Naturally this necessity, he contends, prompted 

 to the Martians the canal idea. Of course the system 

 now in evidence was not constructed in a day. It was 

 the result rather of slow growth, developing painfully 

 in inverse ratio to the failing sources of supply. 



4. The undertaking, he suggests, was far less for- 

 midable than a similar one would be here. First of all, 

 the flatness of the surface would render the mere dig- 

 ging easy. Then again, on account of the lesser surface 

 gravity, the efficiency of the machinery would be per- 

 haps quadrupled. If to these positive advantages be 

 added the permissible suppositions that the Martians are 

 gigantic, and also further advanced in the mechanical 

 arts than ourselves, the objection on the score of mere 

 physical difficulty is, he reasons, largely eliminated. 



5. The surface being flat, every point within as 

 well as beyond the polar circles would be in stable equi- 

 librium. This means that the water would not descend 

 through the canals at any useful speed without artificial 

 propulsion. Observation proves to him that the canals 



