Reductions to Standard Instruments 



67 



From Table 11, the "half polarity-differences" are obtained for sea dip-circle 35, as 

 based on all available data. 



The adopted formulfe resulting from least-square adjustments of all available data for 

 the logarithms of the total-intensity constants are given in Table 12. 



'Axle of loaded-dip needle 4 was broken during swing observations Feb. 16, 1906; the mean ob3er\'ed values of 

 intensity constants are adopted for short period, during which needle 4 was used with needle 3. 



'Loaded-dip needle 8 of circle 163 was replaced at Yokohama Aug. 23, 1906, by needle 4 of circle 169. The 

 intensity constants were determined only at two shore stations, viz. Tokio and San Diego; hence, available data 

 are ineufficient for deriving coefficients of (AT)'-tcrms. 



