142 EOGEES AND McLEOD ON THE 



From the means of the equations for stars of the same cnlminatiou we have, after 

 combining the corresponding equations in Groups II and II,' Circle East, and neglecting 

 weights : 



Cirde East, U.C. (1) = + . 74 — 1 .11« + c = + -55 — .91a + c = + .52 — .81a + c 



L.C. (2) = - .19+ .51a — 0=— .28+ .61a— c = — .33+ .68a — c 



Circle West, ttC. (3) = + 1 .16 — l-Ola- c 0= + 1.04— .89a — c 0=+ .95— .79a — c 



L.C. (4) = — .58+ .42a +c = — .68+ ..53a + c = — .81+ .66a +.c 



From the combination of : 



I. 11. in. 



« s. s. s. 

 (l)and(2), a= + 0.92 c= + 0.28 a = + 0.90 c= + 0.27 a= c= 



(3) and (4), + -98 + .17 +1.00 + .15 . ■ -^ j-. 



(l)and(3), + .90 + .25 + .88 + .25 + o'.'92 + o'.23 



(l)and(4), + .86 + .22 + .85 + .23 + .90 + .21 



(2) and (3), + .89 + .26 + .85 + .24 + .87 + .26 



(2) and (4), + .83 + .28 + .84 + .23 + .85 + .25 



Since there is no decisive evidence of a change in the value of the constants during 

 the reversal, it is better to choose the values derived from the combination of the equa- 

 tions for opposite positions of the telescope. Combining the last four A'alues in each 

 group we have : 



p. s 



From Group I. a = + 0.87 c=+0.25 



From Group 11. a=+ .86 c=+ .24 



From Group III. a=+ .88 c=+ .24 



It will be instructive to compare the values of a for different values of c in the dif- 

 ferent groups. Assuming c = + . 10, + . 25 and + . 40, we have : 



