8 KANT'S PRELIMINARY DISCUSSION 



of the earth, we can easily find how much time must pass 

 until this hindrance has exhausted the whole motion of 

 the earth. For this there would be required two million 

 years, if the velocity of the swelling ocean is assumed to 

 continue the same to the end and the mass of the earth 

 to be of equal density with the matter of the water. On 

 this footing the said diminution does not amount to much ; 

 but yet in moderate periods, as, for example, within a 

 range of two thousand years, the retardation would amount 

 to so much that the course of a year would then be eight 

 and a half hours less than before, because the axial rotation 

 would have become so much slower. 



The diminution of the daily motion is indeed subject 

 to great limitations, for the following reasons: (i) The 

 density of the whole mass of the earth is not, as was 

 here assumed, equal to the specific gravity of the water; 

 and (2) the velocity of the swelling ocean in its open 

 expanse appears to be much less than one foot in a 

 second. But, on the other hand, this want is abundantly 

 compensated by the fact that (i) the force of the globe, 

 which has here been calculated as rushing on in its move- 

 ment with the velocity of a point under the equator, is 

 only an axial rotation which is much less, and, moreover, 

 the hindrance which is applied at the surface of a rotating 

 globe has the advantage of leverage by its distance from 

 the centre, which two causes taken together increase the 

 diminution caused by the onset of the waters by 5^; 

 and (2), what is the chief consideration, this action of the 

 moving ocean takes place not merely upon the inequalities 

 that tower above the bottom of the ocean the mainland, 

 islands, and cliffs but it is exercised upon the whole bed 

 of the ocean. This action amounts, indeed, at every point 



