8g8 



PRTXTIPLES OF STRA'l'K ik AIM IV 



other, may have heen in ancient times very far from their present 

 geographical position, and may have gradnally shifted through lo, 



Fig. 246. Map of the lu'inisplicrcs, showing the liypothelical migration of 

 the North I'olc during the successive geologic periods. 

 (Jacohilti.) 



20, 30, 40. or more degrees, without there being at any time any 

 perceptible sudden disturl)ance of either land or water." (42:7/.) 



Fig. 247. Map of the hemispheres, showing the h3'pothetical migrations of 

 the South Pole during the successive geologic periods. (Jacobitti.) 



Various theories have been advanced to account for and ex- 

 plain such wanderings of the poles, but at present the whole sub- 

 ject is too little investigated to make their discussion profitable. 

 Geologists must first gather a larger body of facts, which will tend 



