WEIGHING THE WORLDS 



of "canals" net-wofking the surface of Mars depends 

 upon the acuteness of vision of the observer, or upon 

 the size of the telescope that aids his vision. The 

 Italian astronomer Schiaparelli, who first observed 

 the canals, was gifted with peculiarly acute vision; 

 and Profesor Lowell's observations are made in an 

 atmosphere of great clearness. These observers, and 

 a few others who have thought they saw the mark- 

 ings, would be likened by Professor Maunder to the 

 children in the middle of his schoolroom. The other 

 observers, who failed to see the markings, are like 

 the children at the back of the room or at the front, 

 according to the more or less favorable conditions 

 under which their observations are made. 



It seems more than probable, then, that the canals 

 of Mars are an optical illusion, and that their pres- 

 ence can not be legitimately invoked as proving the 

 habitation of our neighbor planet by intelligent be- 

 ings. Meantime students of solar physics calculate 

 rather conclusively that unless Mars is blanketed 

 with a rather dense atmosphere and the reverse of 

 this is believed to be the case its surface condition 

 must be one of very low temperature, making it alto- 

 gether unlikely that any animal life comparable to 

 that of the earth can exist on the planet. 



As to Venus, the conditions are very different, and 

 in Professor Maunder's view the probability that 

 this planet may be the abode of life is considerably 

 greater. Venus has a dense atmosphere and it is 

 near enough to the sun to receive nearly double the 

 heat and light received by the earth. So there is 

 no obvious intrinsic reason why life may not exist 



7 89 



