8 SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION 



Corrected distances on new brass deflection bar at o Centigrade : 

 r log r log % S log C 



30.003 cm. 1.47716 4.13045 5.86889 



40.003 cm. 1.60209 4-505 2 4 5-49441 



For an increase in temperature of i Centigrade log C decreases 0.000025 



One division of scale = I'.^j 



Temperature coefficient : 7=0.00030 for i Centigrade 



Induction coefficient : fi = 5.63 ; 



(2/A 

 i +] = o.oooi8 



= 40 cm. = 0.00008 



Distribution coefficient : P i.oo ; 



When r 30 cm. log ( i -- , J = 0.00048 



= 40 cm. =0.00027 



Moment of inertia : 



Temp. Cent. log n'J? 



10 262 



o 273 



+ 10 283 



+ 20 294 



These constants are adapted for the methods of computation in use by the Coast and 

 Geodetic Survey, where the following formulae are used in computing horizontal intensity : 



d 



(H 

 ig 



In these formulae, 



H = horizontal intensity 



m = magnetic moment of magnet 



T' = observed time of one oscillation corrected for rate of chronometer 



A = angle through which magnet is turned by turning the torsion head through an 



angle / 



t ' temperature of oscillations 

 / - temperature of deflections 

 u = deflection angle 



