1006 
and therefore 
90 00 oo oa r 
a2 » 
1 dd s- Kk a dr (a? 
== + di 3 dr dr +1 4— | —dr). 
2 3 „2 2 „2 „2 4 „2 2 
c c 7 7 1 JJ r 
r F a5 r 0 
At a great distance from the attracting centre we may put 
a=a,, (constant) and 9 = 0. In this way we get 
If we now put 
1 pee ree 
zate f5 n= |, 
u 
we may write 4k°/c'a, for x? in the last term of s, and so we find 
1 i 2k ok? a 
5s — rs + ee + Zer? . . . . . . ( ) 
We further put 
p=—1+5,¢=—-—1+7. 
The first and second of the equations (10) then become 
be 4 “a AGN: 
= (6) = AED 
Aer” c 
EN xa? * Ont 
— (r°n 2 (En) — ——- = — Qr", 
dr an) 5) ed ae: 
from which it follows that 
nae 
<I Ek m= A (P+ 29475 
» (15) 
dare z was 
=i Ee = 7) =e == 1 (P—Q — 
Ip 2074 5,2,2° 
in this P and Q must be calculated up to the terms of the 
first order, which can take place by the aid of an equation, that 
follows from (8) viz. 
if one more relation is given between Pand Q If e.g. P=, then 
AL 
eo} 
5 ene xr ("ao 
= + 2n Ts 5 Sas + === aodr = a dr, 
4c? 
£ r 
