Analysis ofihe Mtcdnique Celeste of M. La Place. 471 

 methodical distribution, which was nearly the same with 

 what I have given here. But in the midst of this complica- 

 tion of inquiries, directed towards so many various objects, 

 there are always some which arc attended with doubts, and 

 there are details which either escape us or remain imperfect. 

 I have said enough to convince my readers how advantageous 

 I found it to be placed in the same establishment with Gil- 

 let, Lelievre, Lefebvre, Dolomieu, Brogniart, Vauquelin, 

 Coquebert, Tonnellier, from whom 1 imbibed informa- 

 tion and advice. Several important points have been fully 

 and coolly discussed among us ; and when the sentiments 

 which flow from a perfect intimacy are freely given in 

 friendly discussions, they produce reflections and observa- 

 tions of great value. The conflict of opinions only paves 

 the way for a better understanding among the disputants, 

 and the cause of true science is uniformly promoted by such 

 discussions. 



LXXXIII. Analysis of the Mecanique Celeste of M. La 

 Place. By M. Biot. 



[Continued from p. 270.] 



Book Second. 



After having developed the laws of motion of bodies 

 when actuated by known forces, the author proposes to as- 

 certain what should be the general cause of the celestial mo- 

 tions, in order to reconcile them with actual observations. 

 Setting out therefore with the consideration of the. ellip- 

 tical motion of the planets, and the laws discovered by- 

 Kepler, he concludes that the force which attracts the planets 

 and comets is directed towards the centre of the sun, that 

 it is reciprocally as the square of their distances, and that it 

 only differs in different bodies in proportion to these di- 

 stances. The motion of the satellites around their planets 

 presenting nearly the same phenomena as that of the 

 planets round the sun, the satellites are attracted towards 

 the planets and the sun, by forces reciprocally as the 

 squares of their distances. This law extends to satellites, 



Gg4 whose 



