138 HISTOEY OF PHYSICAL ASTRONOMY. 



(in 1762), at the early age of thirty-nine, worn out by his incessant 

 labors ; and his widow sent to London a copy of his Tables with addi- 

 tional corrections. These Tables were committed to Bradley, then As- 

 tronomer Royal, in order to be compared with observation. Bradley 

 labored at this task with unremitting zeal and industry, having him- 

 self long entertained hopes that the Lunar Method of finding the Lon- 

 gitude might be brought into general use. He and his assistant, Gael 

 Morris, introduced corrections into Mayer's Tables of 1755. In his 

 report of 1756, he says,' 7 that he did not find any difference so great 

 as a minute and a quarter; and in 1760, he adds, that this deviation 

 had been further diminished by his corrections. It is not foreign to 



9 & 



our purpose to observe the great labor which this verification required. 

 Not less than 1220 observations, and long calculations founded upon 

 each, were employed. The accuracy which Mayer's Tables possessed 

 was considered to entitle them to a part of the parliamentary reward ; 

 they were printed in 1770, and his widow received 3000/. from the 

 English nation. At the same time, Euler, whose Tables had been the 

 origin and foundation of Mayer's, also had a recompense of the same 

 amount. 



This public national acknowledgment of the practical accuracy of 

 these Tables is, it will be observed, also a solemn recognition of the 

 truth of the Newtonian theory, as far as truth can be judged of by men 

 acting under the highest official responsibility, and aided by the most 

 complete command of the resources of the skill and talents of others. 

 The finding the Longitude is thus the seal of the moon's gravitation to 

 the sun and earth ; and with this occurrence, therefore, our main con- 

 cern with the history of the Lunar Theory ends. Various improve- 

 ments have been since introduced into this research ; but on these we, 

 with so many other subjects before us, must forbear to enter. 



Sect. 3. Application of the Newtonian Theory to the Planets, 

 Satellites, and Earth. 



THE theories of the Planets and Satellites, as affected by the law of 

 universal gravitation, and therefore by perturbations, were naturally 

 subjects of interest, after the promulgation of that law. Some of the 

 effects of the mutual attraction of the planets had, indeed, already 

 attracted notice. The inequality produced by the mutual attraction of 

 Jupiter and Saturn cannot be overlooked by a good observer. In the 



17 Bradley '3 Mem. p. xcviii. 



