406 THE CUPOLA OF ICE AT THE SOUTH POLE. 



will show this difference, but the following table makes it 

 more apparent. Taking each parallel as unity, the proportion 

 of sea is as follows : 



60 North . . 0.353 10 South . . 0.786 



50 . . 0.407 20 . . 0.777 



40 . . 0.527 30 . . 0.791 



30 . . 0.536 40 . . 0.951 



20 . . 0.677 50 . . 0.972 



10 . . 0.710 60 . . 1.000 



0.771 



Certainly a progressive increase of sea, which is so remarkably 

 regular, can hardly be the result of accident. 



M. Adhemar maintains that this is due to the alteration of 

 the centre of gravity of the earth, caused by the great southern 

 cupola of ice, and consequently that 11,120 years ago (i.e. 

 10,500 years before 1248), when the northern hemisphere 

 was at its coldest, the northern glacier consequently at its 

 maximum, and the southern at its minimum, the preponde- 

 rance of water would have been in the northern hemisphere, 

 and the submersion of the lower lands of Europe and America 

 may have been due to an alteration, not in the level of the 

 land, but in that of the sea. He conceives that when the 

 increasing cupola counterbalances the decreasing one, there is 

 a sudden transfer of the centre of gravity of the earth from 

 one side of the centre of the solid part to the other, and con- 

 sequently a rush of water, or deluge, alternately from north 

 to south and from south to north, occurring every 10,500 

 years. It seems to me, however, that the alterations of the 

 ice cupolas would be too slow, and consequently the change 

 in the centre of gravity too gradual, to cause any sudden rush 

 or deluge of water from the one pole to the other. 



According to this theory, the year 1248 was that in which 

 our northern hemisphere was at its period of greatest heat, 



