160 DR. C. CHREE: AN ENQUIRY INTO THE NATURE OF THE RELATIONSHIP 



TABLE IV. Kew (Units 1' for Angles, ly for Force Components). 

 Observed less Calculated Values. 



Pawlowsl Data (59 41' N. Lit., 30 29' E. long.). 



10. Magnetic observations at tbe three Russian magnetic observatories at 

 Pawlowsk, Kathariuenburg, and Irkutsk are published very nearly on parallel lines 

 under the auspices of the Central Physical Observatory at St. Petersburg. The 

 results are very complete, and are kept well up to date. For the present enquiry I 

 have selected Pawlowsk and Katharinenburg. The former is, I believe, the furthest 

 north magnetic observatory which has been in continued existence for any length of 

 time. Its results include very full details of diurnal maxima and minima, and of the 

 amplitudes of movements in magnetic storms. They are not confined to " all" days, 

 but give in addition full particulars for selected " quiet" days, or " normal" days as 

 they were called by WILD, to whom the idea of their separate treatment is due. 



I have treated the Pawlowsk data for the 11 years 1890 to 1900 by the method of 

 groups, taking the same combination of years as for Kew, viz., 1892 to 1895 for sun- 

 spot maximum, and 1890, 1899, and 1900 for sun-spot minimum. 



Table V. refers to the ranges from the mean diurnal inequalities for the several 

 months of the year, both from " all" and " quiet" days. The seasonal and yearly 

 values of a and b are arithmetic means from the included months, and these 

 arithmetic means are employed in calculating the seasonal and yearly values of bja. 





