TRANSLATOR'S INTRODUCTION xlvii 



Academy, ' on the existence of a new cause, having 

 a sensible influence on the value of the secular 

 equation of the Moon/ 1 propounding practically 

 Kant's solution again. Adopting Delaunay's sug- 

 gestion as true, Adams, in conjunction with Pro- 

 fessor Tait and Lord Kelvin, calculated the 

 diminution of the Earth's rotatory speed with 

 incomparably greater accuracy than ever before, 

 but still on the basis of Kant's original idea. 

 Lord Kelvin has done much by his important rele- 

 vant discussions to promote the elucidation and ex- 

 tension of Kant's point of view, as in his discussion 

 of the 'Thermodynamic Acceleration' of the rotation 

 of the Earth (Transactions Roy. Soc. of Edinburgh, 

 1 88 1 -2, p. 396); and he informs us that his brother, 

 the late Professor James Thomson, of the University 

 of Glasgow, independently grasped the discovery in 

 1840, and discussed it in conversation. The late 

 Dr. Croll also treated the subject with his well- 

 known acuteness and ingenuity. The very remark- 

 able mathematical and physical speculations of 

 Professor H. G. Darwin on the action of Tidal Friction 

 and the formation and movements of the Moon, 

 have given a new interest to the subject, and bring 

 it up to date. 2 And now we begin to pluck the 

 ripe fruit of Kant's seminal idea. 



1 ' Sur 1'existence d'une cause nouvelle ayant une influence sensible 

 sur la valeur de 1'equation seculaire de la Lune.' Comptes rendus, 

 T. 61, p. 1023. 



2 The Tides, 1898, the Art. 'Tides' in the Encyc*. Brit., 9 ed., and 

 the celebrated Papers in the Philosophical Transactions, 1879-1881. 



