156 THE OCEAN. [Book VI. 



shores of Chili ; and the rise and fall is less, in 

 proportion as the space through which it moves is 

 greater than that through which, in the equatorial 

 regions, the same tide moves westwards. Thus, in 

 the temperate zones of the South Atlantic Ocean (in 

 the neighbourhood of the River Plate), the rise and 

 fall of the tides is less than in the equatorial regions, 

 because the space through which they move is greater 

 than that of the equatorial tides which they counter- 

 balance. In the South Pacific Ocean the tides, 

 which roll eastwards in the temperate zones, have a 

 considerable rise and fall against the shores of Pata- 

 gonia, in order to counterbalance those which roll 

 westwards, through the long extent of the equatorial 

 regions, to the East Indies. 



The action of the coast-lines in crowding the tide 

 in some parts of the ocean more than in others, is seen 

 or^ a smaller scale wherever parts of a tide are raised 

 higher than other parts of the same tide by the crowd- 

 ing action of the coast-lines of bays and estuaries. 



PART in. 



CONVERGENCE TOWARDS THE EQUATOR. 



In an ocean completely enveloping the earth the 

 tide would, according to Chapter X., be an hour 

 earlier on the average for each fifteen degrees of lati- 

 tude as well as for each fifteen degrees of east longi- 



