MARS IN HIS ICY CUIRASS 103 



3. Now Mars' polar caps are exceptionally exten- 

 sive, and for their production demand the existence of a 

 relatively large ocean surface. This requirement is ren- 

 dered more imperative by the sun's remoteness, and is 

 even further accentuated by the compulsory exclusion 

 from the available evaporating surface of that part of 

 it covered, for the time being, by the opposite cap. 



4. If Mars' seas bear a similar ratio to its solid 

 kernel as ours do to the earth's, the surface there must 

 be pretty generally covered to the depth of a mile or 

 more. This assumption, it may be said, is sustained 

 by my theoiy that rotation is due to the sun's tidal 

 action. Mars rotates on its axis in 24 hrs. 40 ms., a 

 period reasonably consistent with the earth's case, when 

 their respective masses and solar distances are taken 

 into the reckoning. 



5. The center of gravity of Mars ( according to my 

 argument regarding the earth) lies toward its north 

 pole, and conformably w r e can see the land there re- 

 vealed, while the southern pole is entirely covered with 

 water. 1 



The conclusion is inevitable: The hitherto sup- 

 posed lands, with the possible exception of the blue- 

 green patches,, musty after all, be seas, and the riddle of 

 the markings must be solved on that basis. 2 



Now it goes without saying that water in its fluid 

 state may exhibit great waves, but these quickly vanish 

 and leave no permanent signs. The insistent reality 

 about Mars, however, is its frigidity, and this fact ought 

 long ago to have prompted the thought that the oceans 



1 If it could be shown that Mars' form is somewhat more rotund 

 about the region of its antarctic circle than at its arctic, the circum- 

 stance would tend to corroborate my views, but the disparity is prob- 

 ably too slight for detection. 



2 Since the blue-green patches also exhibit similar, though much 

 less distinct, marks around their margins, these latter may be regarded 

 as mingled sea and land .something like the marshes near Atlantic 

 City, or the Everglades of Florida. 



