THE RED PLANET. 525 



or may yet have, to pass through what has been termed a " life-bearing 

 stage." We on earth are at present in the enjoyment of that stage. So far 

 as we can tell, therefore, Mars may be inhabited now, as he bears much the 

 same appearance as our planet. Certain changes are going on in Mars, and 

 all planets, just as they go on here in our earth, and as they did long, long 

 ages before the earth was populated, and which will continue to go on after 

 life on the earth has ceased to exist. 



Mars is, as we know, much further away from the sun than earth is, 

 and must receive less direct heat. When he was created, or formed, we can 

 only conjecture, but in all probability he cooled before the earth did, as he 

 is smaller. Here another theory concerning the state of Mars arises, and in 

 support of it we may quote an American authority upon the planet. 



" His mass is not much more than one-ninth of the earth's, while his 

 surface is about one-third of hers. Then, if originally formed of the same 

 temperature, he had only one-ninth her amount of heat to distribute. If 

 he had radiated it away at one-ninth of her rate, his supply would have 

 lasted as long, but radiation takes place from the surface in proportion to 

 the surface, hence he parted with it three times as fast as he should have 

 done to cool at the same rate as the earth, and must have attained a con- 

 dition which she will not attain until three times as long an interval has 

 elapsed from the era of her first existence than has already elapsed. Geolo- 

 gists agree that the last-named period must be measured by many millions of 

 years ; hence it follows that twice as many millions of years must elapse 

 before our earth will be in the same condition as Mars, and Mars must be 

 three times as far on the way toward planetary decrepitude and death as our 

 earth. Then assigning two hundred thousand years as the extreme duration 

 of the period during which men capable of studying the problems of the 

 universe have existed, and will exist on this earth, the theory holds that 

 Mars would have entered on that stage of his existence many millions 

 of years ago, and that the appearance of the planet itself implies a much 

 later stage of planetary existence." 



Mars is a very interesting study, and the reddish hue which is so dis- 

 tinctive is perceived in certain spots when examined by the telescope's aid. 

 These red places were discovered by Cassini. Mr. Dawes made drawings 

 of Mars, and Mr. Proctor has by their aid constructed a regular map of Mars, 

 and a chart of the surface of the planet. There is much more land than 

 water on Mars, as the bright surfaces which indicate land are much more 

 extensive than the darker portions which betoken the existence of water. 

 But these " markings " are not always visible, in consequence of something 

 coming between us and the land on Mars, and this has been attributed to 

 the production of vegetation, which a French savant declared was ruddy- 

 coloured, and that this autumnal tint departed in the winter. 



The seasons of Mars are not equal, in consequence of his wandering 

 propensities, and winter is warmer up there than our winter, while summer 

 is cooler than our summer. That there are clouds and an aqueous atmo- 



