( 100 ) 



same supposition the means from the north, and the south stars are 

 free from these two errors. 



To derive the errors of division and of flexure we obtain, the 

 mean zenith distance amounting to 49\ with the same notations as 

 before : 



a'= 2a sin 98°= — 10." 16 



b' = — 2b sin 98° = -f 0. 83 

 c = 2c sin 49° = — 2. 66 

 whence, if a stands again for the circle reading: 

 Correction for division errors to the circle reading — 5. "13 sin 2a — 0. "41 cos 2« 



= -f 5."1 5 sin (2a- 175.°4) 

 Correction for flexure to the zenith distance — 1."7 6 sin z. 



The mean of the values in the last column is : 



<f = — 5°12'4".34. 

 The formula for the correction for division errors agrees very 

 well with that derived from the observations of 1900 — 01, which is 

 of importance for the correction of my other observations of zenith 

 distances. For the coefficient of the flexure I had formerly found 

 — 0."60 ; the difference may still be ascribed to accidental causes. 



Finally 1 give here the 12 separate results for thé latitude, each 

 corrected for division errors and flexure, (see p. 101). 



Their mean value must of course be equal to that of the uncor- 

 rected results. From the comparison of the former with their mean 

 we derive for the mean error of the final result ± 0."57. Hence 

 this is : 



( f = — 5 12 4 .34 =t O .57. 



