Chap. IV.] GRAVITATIOX AND INERTION. 66 



regions, the earth's gravitation causes an equal volume 

 to outrun the surface in higher latitudes, and thus 

 the equilibrium of the ocean, as a whole, is main- 

 tained in the position in which universal gravitation 

 tends to hold it.^ 



Thus, then, the whole system of oceanic circula- 

 tion which we have shown to result from the action 

 of vis-inertice — in consequence of the greater force 

 brought into play in those parts of the ocean which 

 are moved with greatest velocity overwhelming the 

 lesser forces in other parts of the ocean, and in con- 

 sequence of the force acting along the surface of the 

 deep and central parts of the ocean overwhelming 

 that acting along the shores — is just as truly the 

 effect of the opposing action of astral and terrestrial 

 gravitation, in consequence of the earth in its motion 

 tending to carry the particles of the ocean from the 

 positions in which universal gravitation tends to hold 

 them. 



' See also Chapter XXI., Proposition XXVII, 



