166 DE. C, CHEEE: AN ENQUIRY INTO THE NATURE OF THE RELATIONSHIP 



In the case of the annual range, 1893 has fallen to the eighth place in D and 

 ninth place in V, whilst 1898 mounts to the third or even the second place. 



In the mean daily, mean monthly, and annual ranges, 1892 and 1894 are as 

 conspicuously in excess of what one would expect from sun-spot frequency as 1893 

 and 1895 are below it. Thus when we treat these four years as a unit, and compare 

 it with a similar unit made up of the three years 1890, 1899, and 1900, we may 

 arrive at a conspicuous connection between sun-spot frequency and amplitude of 

 disturbance ; but at the same time there is a marked absence of the close and regular 

 connection in individual years which characterises the inequality ranges in D, H, 

 and I. 



TABLE IX.-Pawlowsk (Units 1' for D, ly for H and V). 





18. It was pointed out in (A), 74 and 75, that whilst an intimate general 

 connection between sun-spot frequency and diurnal magnetic ranges is unmistakable, 

 it is open to doubt whether the mean values of these quantities for so short a period 

 as a single month can be regarded as directly interconnected. 



If both phenomena proceed from a common cause whose intensity of action at a 

 given instant varies throughout the solar system, then it might possibly be better to 

 compare monthly magnetic ranges with sun-spot frequency for a longer overlapping 

 period. 



As shown in (A), Table I., the mean sun-spot frequency for individual months of 

 the year from the period 1890 to 1900 varied from 35 - in November and 35'5 in 

 March to 4.5 '4 in June and August. Clearly, if the connection between sun-spot 

 frequency and magnetic range is of the more general kind indicated above, the values 

 we have found for b and b/a at Kew and Pawlowsk will be too large in months such 

 as November and March and too small in months such as June and August. 



To obtain an outside estimate of the uncertainty thus existing, I have calculated 

 values for a, b and b/a for the "quiet" day Pawlowsk data, employing WOLFER'S 



