LIFE IN MARS. 1 1/ 



of the bright spots, were due to the progress of the 

 Martial summer. Precisely as in our summer months, 

 those who voyage across the Atlantic may sail in far 

 higher latitudes than they could safely venture to tra- 

 verse in winter, so in Mars the polar ice and snow is 

 limited within a far narrower region in summer than 

 in winter. 



But after all (it may be urged), to suppose that these 

 two bright spots are formed in reality of ice and snow is 

 rather venturesome. Might we not imagine that some 

 other material than water is concerned in the observed 

 changes ? What reason have we for inferring that the 

 same elements that we are familiar with exist out yonder 

 in space ? 



The answer to these questions, or, rather, the 

 answers, for we have to do with a whole series of facts, 

 dovetailing in the most satisfactory manner into each 

 other, will be found full of interest! 



We all know that Mars shines with a ruddy light. 

 He is, indeed, far the ruddiest star in the heavens : 

 Aldebaran and Antares are pale beside him. Now, in 

 the telescope the surface of Mars does not appear wholly 

 red. We have seen that at two opposite points his 

 orb exhibits white spots. But, besides these regions, 

 there are others which are not red. Dark spaces are 

 seen, sometimes strangely complicated in figure, which 

 present a well-marked tinge of greenish blue. Here, 

 then, we have a feature which we should certainly 

 expect to find if the polar spots are really snow-caps ; 

 for the existence of water in quantities sufficient to 



