76 



LECTURES ON THE LUNAR THEORY. 



[LECT. xvi. 



If we take the variable plane defined by the longitude of the node 

 JV and the inclination i as the plane to which the position of the Moon 

 is referred, we have the latitude of the Moon above this plane 



= Ai sin 9 &.N sin i cos 9 



- m sin i cos- - 



X /, 



1 + - m cos i 

 4 



m ' 

 1 m 



sin (0- 200 



- m" sin i cos i sin 6 



. . . , 

 + - m sin i snr - 



8 2 



-! 



cos 



sin (0 + 20'). 



