1111 
Rw,t along the orbit r=A, the axis of # having always the direction 
of the radius and the axis of y the direction of the motion. Then 
the equations pass into 
o=(1 + 5) #— 20, y— 80? # (1 za) 
% a : aes 11) 
Ozi tot) ( 
0 =—z—w,?z ) 
or 
a . L \ 
ik EEA vyd ll 
F a : vg) toy EZ) 
jl) 
z= —w,7z. 
We further pass to a system of axes x’, y’, 2’, which revolves with 
respect to a,y,z around the ayis of z with an angular velocity w 
in the sense of y to w, the axis of 2’ coinciding with the axis of z: 
r= 2' coswt + y' sin wt 
y= sinwtd gest).  . . . , (13) 
A MEL 
Then the equations pass into: 
a tho-w,(1- Et y'+ or(1 5) (2' cos? wt y' sin wt cos wt) + 
+ in aa) 
y'— +2.w—w ee 2430, jee z' cos wt sin wt + 'sin? wt) —( 
y ° 0 OR y 
+ o-ta(-s)b 
1 MRE | : / 
. 
(14) 
Being given a spherical body with centre in the origine of the 
system x,y,z and so small, that the squares of its dimensions may 
be neglected. Then, supposing the body with this neglection to be 
rigid, in the expressions of the moments > m (y’ 2’— 2’ y’) cycl. the 
terms with x’, y’, z’ will all contain an inertial product or a difference 
of two equal inertial moments and consequently this terms will 
vanish. The terms with 2’, y’ and z’ then and only then vanish for 
