282 Recent Elevatory Movements, paet n. 



summit nor basal edges of tlieir escarpments may be 

 horizontal. 



Finally, comparing the extent of the elevated area, 

 as deduced from the upraised recent organic remains, 

 on the two sides of the continent, we have seen that on 

 the Atlantic, shells have been found at intervals from 

 eastern Tierra del Fuego for 1,180 miles northward, 

 and on the Pacific for a space of 2,075 miles. For a 

 length of 775 miles, they occur in the same latitudes 

 on both sides of the continent. Without taking this 

 circumstance into consideration, it is probable from 

 the reasons assigned in the last chapter, that the entire 

 breadth of the continent in Central Patagonia has been 

 uplifted in mass ; but from other reasons there given, it 

 would be hazardous to extend this conclusion to La 

 Plata. From the continent being narrow in the south- 

 ernmost parts of Patagonia, and from the shells found 

 at the Inner Narrows of the Strait of Magellan, and 

 likewise far up the valley of the S. Cruz, it is probable 

 that the southern part of the western coast, which was 

 not visited by me, has been elevated within the period 

 of recent Mollusca : if so, the shores of the Pacific 

 have been continuously, recently, and in a geological 

 sense synchronously upraised, from Lima for a height of 

 2,480 nautical miles southward, — a distance equal to that 

 from the Eed Sea to the North Cape of Scandinavia ! 



