The general Characteristics of the frequencyfunction of stellar movements 



69 



Now, of course, the value of t> 1 does not vary so much from square to square 

 as the quantities 0- 1 (a;) and $ x {y), which is clearly seen from the fact that ft^sc) and 

 d-^y) are generally not more equal to each other in the same square than in diffe- 

 rent squares. Most of the variation is to be attributed to the mean errors in x 0 

 and y 0 . These are 



e{x 0 ) = ^ s(*/ 0 ) = ^£ 



and on the whole they lie between the limits 0.15 and 0.05. As seen from the 

 table the differences x 0 ' — a? 0 , and y 0 ' — y 0 generally are of the same order of 

 magnitude as the mean errors, and consequently no weight can be attached to the 

 values of \(x) and ■8 i 1 («/) of the individual squares. The question is, however, not 

 so hopeless when we seek for systematical variations. 



Taking together the squares with respect to their galactic position we find: 



Squares within 30° of the Galaxy 



C w B„ £ 10 , B v # 2 , B & C t [C s excluded) 



Mean iïJx) = 0.052*1 



1 } Mean & = 0.049 



Mean d-^y) = 0.045 J 



Squares partly within 30° of the Galaxy 



<7 9 , B s , A v A 2 , C u 

 Mean b t {x) = O.i 

 Mean ^(y) = 0.< 

 Squares without 30° of the Galaxy 



C 6 , G v C 8 , B 5 , B 6 , C 12 , C v C v B v C 5 . {B n excluded). 

 Mean ftjp) = O.008 

 Mean ^(y) = 0.059 



Mean th = 0.056 



Mean t>, = 0.059 



From these figures we see that the propable variation is of a magnitude to 

 make H = = 1.2. The fact that the variation comes out independently from 

 the x 0 and y 0 components strengthens the probability of this value, which in it 

 self is very plausible. 



For the value of h we obtain 



/ 0049 A 



h = - = 0.94. 



0.052 



For the factor of correction for the second characteristics we now obtain 

 from (85) 



(H a )p = (sl B (l-2y + sf) (0.94) 2 , 

 which gives, using table XV, 



* On account of our having neglected 3° in the right ascension of the Apex this value is 

 slightly too great. 



