XVlll 



Introduction to the Makerstoun Observations, 1844. 



T.VBLE 1. — Determinations of tlie Value of Angle A. 



}- 



23 50' 24"-5 



17. The mean value of angle A from all the observations 



in 1844, 1845, and 1846, .... 

 The mean value of angle A from all the observations \ _,-,.^ „ , , .^g" n 



in lb44, ..... .J 



The value of angle Z (Table 8, Introduction, 1841-2), = 1' 37' 38"-8 

 Whence angle x\ + Z, ..... =25 28' 2"-7 



The absolute westerly declination, therefore, corresponding to the zeros of the 

 scales, No. 8, =25" 28'-04. This value has also been employed for the observa- 

 tions in 1845 and 1846. For other scale readings differing from the zero by the 

 angular quantity ± D, the declination is obtained from the formula, declination 

 = 25' 28'-04 ± D. 



