142 



THE APPARENT POSITION OF THE ZODIACAL LIGHT. 



fine the comparisons to the few adjacent groups which differ only a little in 

 longitude, since the unsystematic variations are evidently large. The remainders 

 in absorption and latitude, given in Table II., were therefore adopted as the 



basis of the corrections. 



The first step taken was to change the signs of corresponding remainders when 

 necessary, so that those derived from the differences of absorption might all be 

 positive. Among the nineteen remainders in latitude formed from the evening 

 observations only four were then negative, and the corresponding remainders in 

 absorption were small. Four negative quantities also occurred among the fifteen 

 remainders in latitude formed from the morning observations. One of them cor- 

 responds to a large remainder in absorption; this is due to the influence of an 

 abnormal group of observations, which will again be mentioned. The general 



o 



cement of 



signs illustrates the dependence of the latitude upon the effects 



of absorpt 



but the variations in the relative magnitude of the remaind 



are 



too irregular to allow a satisfactory system of corrections to be immediately 



i © 



of the data. In order to avoid the pos- 



labor than 



involving more 



apparent from a graphical arrai 



sible effects of prejudice, without adopting a process 

 would be warranted by the degree of accuracy to be expected in the result, the 

 remainders derived from the differences of absorption were next arranged, accord- 

 groups of five each, so far as practicable, and the 

 iponding remainders in latitude were also collected. In this manner four 



ing to their magnitude, in 



formed from the evening observations, and three 



from the morning 



columns give 



groups were 



observations. In each part of Table III. the 



of remainders in each group, their sums, their mean values, and their 

 deviations from these means. 



number 



average 



No. 

 Rem. 



Evening Observations. 



Sums. 



Abs. 



Lat 



0.07 



0.31 



0.93 



2.17 



Means. 



Abs. 



Lat 



o.oi 



0.06 



|MH|Hk|nA4 ^Bfl MMHtttfMHMMflH ____ ■■■ gun/. t i r 



0.19 



0.54 



TABLE III. 



Av. Dev 



Abs. 



0.01 



Lat, 



0.01 



0.06 



0.15 



No. 

 Rem. 



Morning Observations. 



Sums. 



Means. 



Av. E 



Abs. 



Lat. 



Abs. 



Lat. 



Abs. 



0.02 



0.22 



o 



1.2 



0.04 



o 



0.2 



0.73 



7.2 



0.15 



1.4 



0.06 



1.85 



19.6 



0.37 



3.9 



0.10 



Lat 



