262 



THE OCEAN. 



[Book X 



E is to tlie same at t as 1'72 is to 1 (being inversely 

 as the cube of the distance). And the resulting 

 velocities, being as the square roots of the respective 

 forces, would be as 1*312 is to 1, making the velocity 

 at T "76 of the velocity at e. But the length of the 

 parallel at t is only '71 of the length of that at e on 

 the equator ; and therefore a revolving force acting 



from o, sufficient to give the water at e the equatorial 

 velocity, would give to the water at t a greater 

 velocity than that of the surface of the earth at t. 



6. Or, since the velocity of motion at the equator 

 is 1,000 miles an hour, and on the 45th parallel 710 

 miles an hour ; and since the retarding action of 

 astral gravitation is as the square of the velocity ; 

 therefore the relative retarding action is — 



At the Equator 



On the 45 th parallel 



1,000,000 

 504,100 



But, as shown in the foregoing section, the relative 

 revolving force in the same positions is as 1' 72 is to 1, 



