Chap. II.] INERTION. 25 



for the supply of those of another, the streams must 

 run due west right round the world in every lati- 

 tude. In such case westward pressure would be 

 acting due west in all parts of the ocean, and none 

 of its attributes would be brought into play. 



Since, however, we have shown that lesser forces 

 must yield to greater forces, and, since the force of 

 westward pressure is greater at the surface than at 

 the bottom of the ocean, therefore, though no one 

 meridian will yield to any other, the diverging ten- 

 dency of the lower strata of water must yield on 

 every meridian to the greater force of the upper 

 strata ; so that the lower strata would consist of 

 converging streams, which, at the point of conver- 

 gence, must rise upwards to supply the diverging 

 streams of the upper strata. 



Thus in the lower strata converging streams 

 would be running towards the equator at all points 

 from the north-east and south-east, and in the upper 

 strata diverging streams would be running from all 

 points of the equator towards the north-west and 

 south-west. 



It is clear that the streams of the upper strata 

 must supply those of the lower. Let us consider 

 what course they must pursue between their depar- 

 ture from and their return to the equator. 



It is obvious that the streams of the upper strata, 

 running from the equator at all points, must, as they 

 proceed on their course, become compressed in con- 



