32 C. V. L. Charlier 



aud similar formulae for the other components. lacohiana is = 1, and further is 



and 



so that 



and 

 where 



Wi + Mi2 



Introducing polarcoordir^ates 



= sin cos , C/g ''2 ^^^^ ^2 '^2 ' 

 = sin sin , Fg = sin feg sin a,^ , 

 ^'^1 ~ ''1 cos fej , ^ *'2 c*^'^ ^2 



we get 



dl\ dV^ dW\ = r^^ sin di\ db^ da^ 

 dU^d \\ d W., = r./ sin b^ dr,^ db^ da.^ . 



The hmits of integration are: for b^ and b^ 0 to tt, for and 0 to 2n , 

 for and r.^ 0 to + qo . 



The integrations regai'ding b aud a give the factor 47c in both equations, so that 



=° -|- Wîj ^ 



CO 



0 



For the reduction of we put 



a 



and get 



CO 



n 



(mîj + mg)"/' 



