TIJE ORBIT OF UK A \ IS 



35 



The derivatives of A with respect to (log. a = ) are computed in precisely the 

 siune way by simply substituting for b'{\ aDab ( \\ etc., their derivatives with respect 

 to n as given in the above table of constants. 



The quantities Ai,(50)"', etc., which appear in the third series of terms above 

 express that part of the perturbations of Uranus caused by the action of Saturn 



* ID units of the third place of decimals. 



