XII 



THE PLANETS MAES AND VENUS 



NEXT to the earth itself, Mars is by far the most in- 

 teresting of the primary planets, notwithstanding 

 that it is the second smallest. The reason for this 

 lies partly in the fact that on account of its nearness and 

 its favorable location for observation we can obtain a 

 closer and better view of its surface than we can of any 

 other planet, but mainly in the mystery of its so-called 

 " canals" and the question as to whether it is inhabited 

 by an intelligent race of beings. When very closest to us, 

 Mars is still over 35,000,000 miles distant, and this dis- 

 tance varies all the way up to 250,000,000 miles, depend- 

 ing on whether the planet is on the same side of the sun as 

 the earth or not. Inasmuch as the diameter of the planet 

 is only about half (4,200 miles) that of our earth, simple 

 computation will show that, when very nearest, it sub- 

 tends the same visual angle as a 25-cent piece does at a 

 distance of 700 feet ! It should therefore not surprise the 

 reader to learn that there has been a great deal of con- 

 troversy between first-class observers, armed with the 

 best of instruments, as to whether the " canals " exist at 

 all, not to mention the even more indistinct details which 

 Lowell and others claim to have detected. 



The first astronomer to call attention to these lines 

 on the Martian map was the Italian, Giovanni Virginio 

 Schiaparelli (1835-1910), in 1877, who called them canali, 

 which, it is said, does not precisely correspond in mean- 

 ing with the English word " canals " as subsequently 



