198 SPARKS FROM A GEOLOGIST'S HAMMER. 



is, with reference to the preservation of the old center of 

 gravity, the displacement would not actually occur. The 

 protruding polar ice would press the unyielding core of 

 the earth through the spheroidal shell of water suffi- 

 ciently to conserve the position of the center of gravity. 

 But the incidental result would be a relative subsidence 

 of the loaded pole and an emergence of the opposite one. 

 These deductions are in perfect accordance with observed 

 geolosfical facts. These show that a general northern 

 subsidence was associated with the glaciation of the 

 northern hemisphere. The deduction is also in accord 

 with the present condition of the south polar regions. If 

 the northern hemisphere is at present in the enjoyment 

 of its geological summer, the southern must be in the 

 midst of its geological winter. The southern hemisphere 

 must be now in a state of glaciation; and, in accordance 

 with what I have just said of the displacement of the 

 earth's center of gravity by the accumulated ice, the 

 south polar regions must be many feet lower, relatively 

 to the sea-level, than they were during the southern geo- 

 logical summer; that is, the lands of the southern hemi- 

 sphere must be extensively submerged. That they are 

 actually submerged is a fact of observation. Commander 

 Wilkes, of the United States Exploring Expedition, coasted 

 seventeen hundred miles along a barrier of ice-clifts l3'ing 

 under the Antarctic circle. These cliffs must rest on solid 

 land; and some thousands of years hence, when the Ant- 

 arctic summei-^ returns, the burden of ice may be removed; 

 those submerged lands may rise again above the surface; 

 the southern extremity of South America may extend it- 

 self to the Falkland and other contiguous islands; Wilkes' 

 Land, Victoria Land and Graham's Land may become as 



