32 THE OCEAN. [Book 11. 



pressure acting along the different parallels of lati- 

 tude, leaving out of consideration altogether the 

 difference between the forces acting at the surface 

 and at the bottom of the ocean. Let us now con- 

 sider the effects of the opposing action of these latter 

 unequal forces. Their tendency is to cause the 

 great westward stream in the equatorial regions to 

 diverge from the equator on both sides ; and there- 

 fore, that stream may be considered as consisting of 

 two separate portions, the one tending to run west- 

 wards and northwards, the other westwards and 

 southwards. And, therefore, on meeting with the 

 obstruction on the western side of the ocean, it is in 

 fact not one stream but two streams ; each of which 

 streams must, on meeting with the obstruction, divide 

 to the right and left ; so that the left-hand division of 

 the northern and right-hand division of the southern 

 stream would meet and turn each other back east- 

 wards, as shown m Plate YII. And this current 

 running from west to east would, for whatever dis- 

 tance it might run, divide the northern from the 

 southern portion of th^ great equatorial current 

 runnmg from east to west, and would to some extent 

 supply the diverging tendencies of that stream. 



Thus the inequality between the forces of the 

 upper and under strata tends to cause a counter-cur- 

 rent to run eastwards, dividing the north from the 

 south equatorial district. 



