20 



SCIENTIFIC RESULTS OF ZIEGLER POLAR EXPEDITION 



The circle reading is found on page 27, under "Circle reading of mag- 

 net," for corresponding time 67° 07'. 3, whence magnetic south 

 meridian reads 67° 22'. 2. 



The true south meridian for the corresponding day and time is (see 

 page 21) 42" 09'. 4. 



Therefore the east declination, uncorrected for any change in the plane 

 of detorsion, is 25" 12'. 8. 



But the plane of detorsion has shifted 29° in the direction of increasing 

 azimuths in gh 49m (see bottom page 71) and the effect of 90° of 

 torsion as observed is 24'. 5 (see bottom page 71), which gives by in- 

 terpolation according to time a correction of — 4'. 4, whence the final 

 value of last magnetic declination as observed at sh com on Novem- 

 ber I, 1903, is 25° 08'. 4. 



Note that in the tabulation of reductions of declination observations the results are entered 

 to the nearest minute ; in those cases where the figure in the tenths of a minute is 5 the rule 

 is followed to take the nearest even minute as the result to be tabulated. 



Tabulations of Records 

 Circle readings of azimuth marks, magnet, and true south at Tcplits Bay 



