SEQUEL TO THE EPOCH OF NEWTON. 253 



Sect. 8. Application of the Newtonian Theory to 

 the Tides. 



WE come, finally, to that result, in which most re- 

 mains to be done for the verification of the general 

 law of attraction ; the subject of the Tides. Yet, 

 even here, the verification is striking as far as 

 observations have been carried. Newton's theory 

 explained, with singular felicity, all the prominent 

 circumstances of the tides then known ; the differ- 

 ence of spring and neap tides ; the effect of the 

 moon's and sun's declination and parallax; even 

 the difference of morning and evening tides, and 

 the anomalous tides of particular places. About, 

 and after, this time, attempts were made both by 

 the Royal Society of England, and by the French 

 Academy, to collect numerous observations; but 

 these were not followed up with sufficient perse- 

 verance. Perhaps, indeed, the theory had not been 

 at that time sufficiently developed ; but the admir- 

 able prize-essays of Euler, Bernoulli, and D'Alem- 

 bert, in 1740, removed, in a great measure, this 

 deficiency. These dissertations supplied the means 

 of bringing this subject to the same test to which 

 all the other consequences of gravitation had been 

 subjected ; namely, the calculation of tables, and 

 the continued and orderly comparison of these with 

 observation. Laplace has attempted this verifica- 

 tion in another way, by calculating the results of 

 the theory (which he has done with an extraor- 



