A WHEWELLITE ESSAY ON MARS. 133 



their range: his arctic, temperate, and torrid zones 

 occupy nearly the same relative portions of his globe 

 as ours do. His day, again, only differs from the 

 terrestrial day by about thirty-seven minutes. Water 

 certainly exists on his surface, and the vapour of water 

 is present in his atmosphere. Oceans and continents 

 can be recognised on his globe they have even been 

 mapped and charted, and globes have been formed of 

 the ruddy planet. The polar snow-caps of Mars can 

 also be seen, and their increase and diminution with 

 the varying seasons can be readily recognised. The 

 signs of cloud and mist and rain, ocean-currents and 

 air-currents, have also been traced. In fine, everything 

 which one could hope to find as indicative of the habit- 

 ability of so distant a world, has been seen in Mars ; 

 and accordingly it is not greatly to be wondered at if 

 the theory that he is inhabited, and by beings not very 

 unlike those existing on our earth, should have been 

 comfortably accepted by most of those who have con- 

 sidered the subject. 



Yet there has always been a serious difficulty in the 

 way. Although the distance of Mars from the sun is 

 not so much in excess of the earth's as to compel us to 

 forego the idea that he is suitably warmed and lighted 

 (reference being always made to the wants of such 

 creatures as we are familiar with), yet there is a suffi- 

 cient discrepancy to render it somewhat surprising 

 that the meteorological conditions on Mars should 

 apparently resemble those on the earth very closely. 

 This would not be the place for nice calculations, and 



