( 238 ) 
I only showed that a determination from the components 7, Le. 
from the condition 
Seam, - - te AN 
does not fulfill this condition. 
Srern’s reasoning thus misses its aim. 
As has been remarked above it seems to me that, in STEIN’s 
opinion, the conditions (8) and (9) are identical, if only care is 
taken to choose the point z near enough to the position which will 
ultimately be found to be the most probable position of the Antapex. 
Perhaps the great difference between the two conditions is best seen 
by comparing the results which they give for the position of the 
Apex in the example which I used formerly to show the inadequacy 
of Arry’s principle. 
Suppose, therefore, two stars at one and the same point of the 
sky, having equal pro- 
per motions Sw and See! 
forming an _ obtuse 
angle. We suppose 
(which can safely be 
admitted for the pre- 
sent purpose) that the 
magnitude of the pa- 
rallatic motion is equal 
for the two stars (say 
=A =A 
It is easily seen that 
in consequence of the 
conditions imposed the 
Fig. 2. Apex must lie either 
on the line QQ' (in which ease the parallactic motion is SA’) or on 
the line VV' (in which case the parallactic motion is SA). The 
question is only on which of these two lines the Apex must be 
sought. 
Now according to my contention, the condition (9) gives the line 
QQ', because: 
Er? for Apex at Q < 27° for Apex at V, i.e. because: 
) 
Bt WO < u A? + ud? 
According to STEIN’s contention the condition (8) gives the line 
