( 368 ) 
where w is a very small quantity. If this is neglected, it follows 
from (27) that the direction towards the Antapex has to be corrected by 
If however for the added star we had 
Po = 180 + ow = — (180 — a’ 
then we should have found for that correction 
180 
AE We 
360° 
noel! 
- 
So there is a leap of 
There is again no foundation for such a leap in the nature of 
the problem, and it does not appear in our solution. 
14. Method of Kororp (Bessel). 
I need but say a few words of this method, as KoBorp himself 
clearly states that his method is not based on hypothesis A. 
He determines the Apex of the motion of the sun in such a way 
that the great circle of which the Apex is the pole, approaches as 
closely as possible to the pole of the proper motions of all the stars. 
To satisfy this condition he makes 
= cos? minimum, 
where Q represents the distance from the Apex of the pole of a 
proper motion. Expressed in the quantities used by us, the condition is 
(28) TE sin? À sin? p minimum. 
This is satisfied if we write down for each star an equation of 
condition 
(29) sindsinp = 0 
and then solve the whole of these equations with least squares. 
This method cannot be tested by the condition (10). It is namely a 
peculiarity of this method, that whereas, according to the other methods, 
from stars of one part of the sky, only a direction can be derived, 
in which the Apex must be situated, we find by KogoLp's method 
a complete determination of the position of that point. 
