70 



canal proper, and it is also probable that much of the dark belt covering 

 the greater part of the southern hemisphere is due mainly to vegetation. 

 These areas deepen in color very decidedly at aliout the time the water 

 would reach them if it were really conducted from the poles to the equa- 

 torial regions in the canals, and after the ice cap is all melted and no evi- 

 dence of other water supply is visible, these areas again turn ligliter in 

 color as if the vegetation dried up or died. 



Some of those who have done the most in the observation of the planet 

 ai'e of the opinion that the extreme regailarity and geometric exactness of 

 the canal system indicate that it is artificial in its origin and it is only fair 

 to say that this is the appearance of the planet wlien seen to the best 

 advantage. While tliis idea leads to tlie conclusion (hat tliere is or has 

 been some sort of intelligent life on ]\lars. yet the canal system die tliey 

 real canals or something else) has as yet no other explanation which we 

 can consider at all possible. If we assume the existence (in the planet of 

 some sort of intelligent life, a canal system sucli as we see would be 

 essential, as we can see no storms and hut very few clouds, the wliole 

 water supply being apparently the melting jdlar cap. 



On the other hand, it is possilile tliat tlie pdlnr cni)s ;ire not ice, but 

 some other material which will vaiiorize in tlie Marti.-m sunlight and 

 solidify during the long polar niglit. I'nlcss .Mars has some s-ource of 

 heat which tlie earth has not, tlie temperature, even at the best, must be 

 far below that experienced at the same latitude on the earth; and as the 

 atmosphere is not more than one-half as dense as ours this difference in 

 temperature is greatly intensified. It has been suggested that the caps 

 are solidified carbon dioxide and we can not say that tliey are not. Tlie 

 most that can be said for this theory is that carlion dioxide will act that 

 way at a low enough temperature, lint it fails to explain in any degree 

 the seasonal changes in color, and suggests no use or origin for the marks 

 called canals. The ice theory a<-counts for everything but the temperature 

 to melt it. 



Consequently, the climatic conditions on Mars, the physical charac- 

 teristics of its surface, its habitaliility and inhabitants are still open ques- 

 tions upon which much time and laltor must lie expended before we can 

 say much about them witli certaintv. 



