Chap. XV.] REFUTATION OF OBJECTIONS. 171 



and equatorial regions, in consequence of which the 

 current-creating action resulting from axial rotation 

 preponderates over that resulting from any motion by 

 which all parts of the earth's surface are moved with 

 the same velocity : — in this, as in the preceding case, 

 a circulation is effected by currents running with the 

 action of vis -inertias in the regions of greatest force, 

 and counter-currents returning to the source of action 

 through the regions of lesser force : and this without 

 the position of the ocean, as a whole, being in any 

 manner affected, as it is carried along with the motion 

 of the earth, firmly held to the earth's surface by the 

 laws of gravitation, which, as we have seen, simply 

 grasp the ocean as a whole, and do not tend to ob- 

 struct the action of any forces, of whatsoever nature 

 they may be, which may tend to cause a change in 

 the relative positions of particles of the same specific 

 gravity. 



It has also been objected against the action of 

 vis-inertigs that it must tend to retard, and therefore 

 in the course of time to annihilate, the motion of the 

 earth. 



But, in the first place, without a knowledge of the 

 nature or mode of action of the forces which cause the 

 various movements of the earth, it is not possible for 

 us to know whether the action of vis -inertia would or 

 would not retard those motions, A cannon-ball is 

 retarded in its course because the retarding action of 



