70 



canal proper, and it is also prol)al)le tliat niuob of tlie dark belt coveriug 

 the greater part of the soutlieru liemispliere 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 lighter in 

 color as if the vegetation dried up or died. 



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

 aj'e of the opinion that the extreme regularity and geometric exactness of 

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

 to say tliat this is the appearance of the planet when seen to the best 

 advantage. While tliis idea leads to the conclusion that there is or has 

 been some sort of intelligent life on Mars, yet the canal system (Ije they 

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

 can consider at all possiljle. If we assume the existence on the planet of 

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

 essential, as we can see no storms and but very few clouds, the whole 

 water supply being apparently the melting polar cap. 



On the other hand, it is possible that the polar caps are not ice. liut 

 some other material which will vaporize in the Martian sunlight and 

 solidity during the long polar night. Unless Mars has some source of 

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

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

 atmospliere 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 they are not. The 

 most that can l)e said for this theory is that carbon dioxide will act that 

 way at a low enough temperature, but 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 accounts for everything but the temperature 

 to melt it. 



Consequently, the climatic conditions on Mars, tlie pliysit-al charac- 

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

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

 say much altout them with certaintv. 



