Chap. IT.] INERTION. 29 



We will now, before applying its action to the 

 ocean as it actually exists, consider its effects if acting 

 in an ocean running north and south from pole to 

 pole, and bounded east and west by an unbroken 

 barrier of land. And we will first consider the 

 effects resulting in such an ocean from the obstruc- 

 tion formed by the barrier of land, apart from the 

 effects resulting from the difference in the relative 

 forces at the surface and bottom of the ocean, and 

 also all effects of friction. 



Let NWSE, in Plate VI., be such an ocean as 

 above described, e w the line of the equator, n the 

 north pole, and s the south pole. 



Now, if the forces of westward pressure were 

 equal on each parallel of latitude, it is obvious that 

 the only effect which could result from its action 

 would be a change in the position of the water — 

 that is, the level of the ocean would be depressed on 

 the eastern and raised on the western side of the 

 ocean. 



Since, however, the force of westward pressure 

 is greatest at the equator, and decreases from the 

 equator towards the poles in proportion with the 

 decreasing circumference of the parallels of latitude, 

 and since lesser forces must yield to greater forces ; 

 therefore, the force of westward pressure created in 

 the equatorial regions must overwhelm the lesser 

 forces north and south, and drive the water eastwards 

 through latitudes at some certain distance from the 



