Introduction. 



XXXVll 



Table 16 — continued. 







Time of one 



Vibration. 







Date. 



Number 

 of 







Adopted 

 Mean. 



Remarks. 









Vibrations. 



Observed. 



Adopted. 







d. h. 





s. 



s. 



s. 





1842. 













Aug. 2 8 



30 



10-42 



10-40 







Aug. 13 8 



40 



10-44 



10-42 







Sept. 7 23 



20 



10-52) 









Sept. 7 23 



10 



10-47V 



10-45 







Sept. 7 23 



20 



10-54) 









Sept. 24 5 



40 



10-55 



10-44 







Oct. 8 2 



30 



10.39) 









Oct. 8 2 



20 



10-29V 



10-30 







Oct. 8 2 

 Oct. 31 2 



20 

 10 



10-36) 

 10-07\ 







• 





Oct. 31 2 



30 



10-191 



10-05 







Oct. 31 2 



20 



10-04/" 







Oct. 31 2 



10 



9-96/ 









Nov. 10 20 



20 



10-31) 

 10-35J 



10-33 





|Nov. 10* e,^. Needle vibrated accidentally 

 (by steel compasses. 



Nov. 10 20 



20 





Nov. 18 23 



20 



10-04) 

 9-96/ 



1000 







Nov. 18 23 



10 



10-0 





Dec. 8 3 



20 



10-04) 

 10-04/ 



9-98 





Dec. 8 3 



20 







Dec. 20 2 



20 



1005 

 10-03V 

 9-98J 









Dec. 20 2 



10 



10-02 







Dec. 20 2 



10 









Dec. 31 2 



10 



9-75) 







..-■-- 



Dec. 31 2 



10 



9-84V 



9-77 







Dec. 31 2 



20 



9-84J 











The adopted time of vibration lias been obtained from tbe last observations in 

 each series, and differs slightly from the observed time of the whole series. 



Table 17. — Effect of the Bifilar and Declination Magnets on the Balance Magnet. 



North End of 





First Series. 





Second Series. 



Magnet. 











Declination. 



Bifilar. 



Balance 

 Reading. 



Effect of Magnet. 



Balance 

 Reading. 



Effect of Magnet. 



Declination. 



Bifilar. 



Declination. 



Bifilar. 







Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



N. 



W. 



-188-0 







+ 231-8 







S. 



W. 



-188-3 



0-2 





+ 231-8 



0-1 





N. 



W. 



-187-7 







+ 232-1 







N. 



E. 



-183-5 





3-4 



+ 234-2 





17 



N. 



W. 



-186-1 







+ 233-0 







The position of the Balance Needle was altered for the second series of obser- 

 vations. 



43. Observations and reductions. 



MAG. AND MET. OBS. VOL. I. ' k 



