BETWEEN SUN-SPOT FREQUENCY AND TERRESTRIAL MAGNETISM. 



169 



The winter values of b and b/a at Katharineuburg are exceptionally large, 

 notwithstanding a marked depression in December and January. 



TABLE XII. Katharinenburg (Units 1' for D and I, ly for H and V). 

 Ranges from Mean Monthly Diurnal Inequalities. 



In I, both a and h are distinctly smaller at Katharinenburg than at Pawlowsk ; 

 in summer and the equinox they are very similar to the corresponding values at Kew. 

 The winter value of b at Katharinenburg is decidedly less than at Kew, there being 

 specially low values in December, January, and February. The mean value of bja 

 for the year is very close to the corresponding values at Kew and Pawlowsk. 



21. Table XIII. gives results for the mean of the absolute diurnal ranges for 

 individual months, with corresponding seasonal and yearly values. The last mentioned 

 correspond nearly to the Pawlowsk data in the first line of Table VII. (see 22 for 

 nature of difference). 



In D the values of a in Table XIII., whilst invariably larger than the corresponding 

 values in Table XII. , are not very conspicuoxisly so, except in winter. The values 

 of b, however, in Table XIII., are conspicuously larger than those in Table XII., the 

 mean values for the year being roughly one double the other. The difference between 

 the values of b/a in the two tables, though less prominent, is unmistakable. 



VOL. coin. A. 



