THE POLAR GLACIERS/ 



The center of gravity of the earth is the center of the sphere 

 formed by the surface of the oceans ; or rather, owing to the 

 flattening of the earth at the poles, it is a point equally distant, 

 in opposite directions, from the level of the sea. The waters, 

 being free to move, must of necessity conform themselves to 

 this equidistance from the gravitating center of the whole mass. 

 Inasmuch, then, as any plane which cuts the earth into two parts 

 through its center of gravity, must equally divide the weight of 

 the whole earth, it follows also that the sam-e plane would exactly 

 bisect the great spheroid of the oceans. In each hemisphere the 

 sea-level in all corresponding parts would be at the same distance 

 from this center and whatever land and mountains there might 

 be above the ocean in one half would have to be counterbalanced 

 by land, or an excess of weight of some sort, in the other half. 

 And this counterpoising weight must itself rise above the level 

 of the sea, unless we say that one side of the world is composed 

 of heavier materials than the other, of which there is not the 

 least evidence or probability. 



If the plane thus dividing the earth be that of its equator, 

 there will be found in the northern hemisphere about 44,000,000 

 square miles of land, and in the southern, so far as is known, 

 about 16,000,000 square miles. Now, the great problem in 

 physical geography is : What is there in the southern hemi- 

 sphere to counterbalance this great excess of land in the northern ? 



Humboldt has estimated that, if the mountains and highlands 

 of Asia were leveled down and made to fill up evenly the low 

 places, the w r hole continent w r ould have a uniform height of 



* Published in Popular Science Monthly in April and June, 1876. The MS was in the hands of the 

 Publishers some months before the appearance of Croll's work on the same subject, " Climate 

 and Time." 



