lii 



Introduction. 



77. In the daily observations 1842, the bifilav magnetometer was observed 

 2 minutes aftey\ and the balance magnetometer 2 minutes before, the minute of 

 declination observaton. 



During the term-day observations 1842, the bifilar magnetometer was ob-. 

 served 2 minutes after, and the balance magnetometer 4 minutes after, the minute 

 of declination observation. 



78. The following is the arrangement of the observers on the term-davs. 



Table 26. — Initials of Observers for each Hour of the Term-Days, from July 1841 till 



December 1842. 



Gbttingen 





^ 



Qi 



a 



U 



g 



a 





>> 



3 













3 



S 



s 



a) 



U 



•a 



u 



a 



Hour. 



1-5 



< 



■1 



1 



o 

 O 



o 



u 



0) 



p 



3 



a 



4 



t-t 



o 



S 



s 



^ 





n 



3 





fco 



3 





o 

 O 



> 

 o 



0) 



o 



10 



R 



B 



A 



R 



B 



R 



R 



B 



w* 



R 



A 



D 



B 



H 



A 



D 



B 



D 



11 



R 



B 



A 



R 



B 



R 



R 



B 



w 



R 



A 



D 



B 



n 



A 



D 



B 



D 



12 



H 



B 



A 



R 



B 



R 



R 



B 



w 



R 



D 



D 



B 



H 



A 



D 



B 



D 



13 



n 



H 



H 



A 



B 



R 



R 



B 



w 



R 



D 



D 



B 



II 



A 



D 



B 



D 



14 



A 



II 



11 



A 



A 



A 



II 



A 



A 



A 



B 



B 



H 



A 



D 



B 



C 



H 



15 



A 



H 



II 



A 



A 



A 



II 



A 



A 



A 



B 



B 



II 



A 



D 



B 



C 



n 



16 



B 



R 



R 



B 



A 



A 



II 



A 



A 



A 



B 



B 



II 



A 



D 



B 



C 



H 



17 



B 



R 



R 



B 



A 



A 



II 



A 



A 



A 



B 



B 



11 



A 



D 



B 



C 



H 



18 



R 



R 



R 



B 



n 



n 



B 



H 



n 



II 



11 



II 



D 



B 



B 



H 



D 



C 



19 



R 



A 



B 



II 



II 



II 



B 



11 



H 



II 



11 



II 



D 



B 



B 



H 



D 



c 



20 



n 



A 



B 



II 



R 



11 



B 



R 



II 



II 



II 



II 



D 



B 



B 



II 



D 



c 



21 



II 



A 



B 



II 



R 



II 



B 



R 



II 



II 



II 



11 



D 



B 



B 



n 



D 



c 



22 



A 



B 



A 



R 



B 



B 



A 



R 



R 



B 



A 



A 



A 



D 



II 



A 



II 



B 



23 



A 



B 



A 



R 



B 



B 



A 



R 



R 



B 



A 



A 



A 



D 



H 



A 



II 



B 







B 



B 



A 



A 



A 



B 



A 



B 



R 



B 



A 



A 



A 



D 



II 



A 



II 



C 



1 



B 



H 



II 



A 



A 



B 



A 



B 



W 



B 



A 



A 



A 



D 



H 



A 



U 



B 



2 



R 



11 



II 



A 



II 



R 



R 



A 



W 



R 



D 



B 



B 



A 



A 



B 



B 



B 



3 



R 



H 



n 



A 



H 



R 



R 



A 



A 



R 



D 



B 



B 



A 



A 



B 



B 



B 



4 



H 



R 



R 



B 



II 



II 



II 



n 



A 



A 



D 



H 



11 



II 



II 



11 



II 



B 



5 



u 



R 



R 



B 



H 



H 



H 



H 



11 



A 



D 



II 



n 



II 



H 



H 



n 



B 



6 



A 



R 



R 



B 



R 



A 



B 



11 



H 



H 



B 



D 



A 



B 



B 



D 



c 



H 



7 



A 



A 



B 



11 



R 



A 



B 



H 



II 



II 



B 



D 



A 



B 



B 



D 



D 



H 



8 



B 



A 



B 



II 



R 



B 



A 



R 



R 



B 



II 



A 



D 



D 



D 



A 



D 



D 



9 



B 



A 



B 



II 



R 



B 



A 



R 



R 



B 



II 



A 



D 



D 



D 



A 



D 



D 



The names of the observers to whom the initials belong will be found, § 2. 



79, The absolute westerly declination is to be obtained from the observations 

 by adding 24° 20', or by deleting the unit in the hundreds place, and prefixing 25°_ 



80. All the readings of the bifilar and balance magnetometer, are corrected for 

 temperature by the quantities given in Tables 11 and 18 ; 300 scale divisions being 

 added to all the bifilar readings. 



* Mr Wallace, of the Edinburgh Observatory. 



