LIFE IN OTHER WORLDS 



some of these considerations to the case of the planet 

 Mars. Next to the Moon Mars is our nearest neighbour, 

 and the erection of great telescopes in America, one of 

 them at Flagstaff Observatory, Arizona, where the air is 

 extraordinarily clear and telescopic vision unusually pene- 

 trating, has stimulated the observation of the planet to a 

 very great degree during recent years. Mars has an 

 atmosphere not nearly so dense as that of the earth, but 

 still dense enough in all probability to support some form 

 of organic life. It may, for example, support vegetation. 

 In some other respects Mars resembles the earth. It 

 has arctic circles ; it has clouds, though whether these 

 are of vapour or of dust is not quite certain ; and it has a 

 less variable temperature by far than that of the Moon. 

 There are, at any rate, some of the conditions to support 

 and perhaps to encourage life ; and if we could be certain 

 that the atmosphere in Mars more nearly resembles that 

 of the earth, and that its temperature was such as to be 

 sometimes above that of our Arctic regions, then it would 

 be difficult to deny that life, and probably intelligent 

 beings, existed there. One very able and intelligent 

 astronomer is convinced that life and intelligent beings do 

 exist there. This is Professor Lowell, of Flagstaff Obser- 

 vatory, who has devoted a number of years and a great 

 deal of money to the careful observation of the planet. He 

 has brought forward many cogent arguments to show that 

 Mars might be inhabited, and that great telescopes can 

 discover signs on it, and may discover further signs, which 

 are a reason for supposing it to be so. It is not, however, 

 within the range of this book to examine these reasons in 



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