68 



Hourly Observations of Magnetometers, December 24 — 30, 1844. 



Declination. Torsion removed, Dec. 2o'i 23*", -GJ" 

 Uii'iLAU. Observed 2™ after the Decliuation, k~ 



; 26'i 23'', + 55** ; 29-^ 23''. O'' ; 30J 3'',- 14°. Effect of + 10° of Torsion = -0-'84. 

 :0-000140. Balance. Observed 3" alter the Declination, A-=0-0000085. 



t Extra Observations made 



Dec. "iSd Oh— 4h. MagiK^t with short scale used in the (ieclinoiootcr. 



Deo. '2Gd ^.'h + Experiments made fur the valiu- of the tursion coefficient of the declinometer thread; effect of OU" of torsion = ~'-bZ. 



* De*-. 2Gd "iSh ■^ The large amoont of torsion now fuunU was most probably introduced on removing the short scale magnet at '2M 4h + as the fibres then 

 became loose. Comparison with tho unililar bi-fore .nnd alter removing tho torsion gave for its eft'ect - V'^, and the effect deduced from the value of the 

 torsion coefllcient = — ft'-J. The observations fr-.m '^M Ih— -.'gh have been corrected by + o'-O^. 



Dec 30d Oh— all. Magnet with short scale used in the declinometer. 



