The Solar Activity 1833-1900. 



291 



It may be again mentioned that as the observations he reduced only 

 begin in the year 1841, no comparison can be made with the epochs of 

 1833-9 and 1837-2. 



Forming the table of maximum minus minimum as before and adding 

 in the last column the values of maximum minus minimum of the 

 sunspot curves from the previous table for the sake of comparison, we 

 have as follows : — 



Magnetic epochs (Ellis). 



Maximum minus minimum. 



Minimum. 



Maximum. 



Magnetic. 



Sunspots. 



(1) - 







3 3 



(2) 1843 -60 



1848-55 



4-95 



4-6 



(3) 1856*15 



1860 '40 



4-25 



4*1 



(4) 1867 -55 



1870 -85 



3-30 



3-4 



(5) 1878 -85 



1883 -90 



5-05 



5-0 



(6) 1889 -75 



1893-75 



4-00 



3-8 



The nearly complete parallelism of the numbers in the last two 

 columns indicates their strict accord with each other. 



The curve showing this magnetic variation is given in fig. 2 

 (curve C), and it is practically a counterpart of curve B. 



The value for the length of the period, as gathered from the interval 

 between the two maxima of this curve at 1843*60 and 1878*85, is 

 35*25 years, which does not differ very much from the value deduced 

 from the maxima of the corresponding sunspot curve, namely, 35*5 

 years. 



Sunspot and Magnetic Curves Combined. Minimum to Maximum. 



By combining the values of the intervals (minimum to maximum) 

 from both the sunspot and magnetic curves, their mean values can be 

 determined as shown in the last column of the following table, the 

 general mean for the whole period being added below : — ■ 



From minimum occurring 

 about 



Mean of sunspot and magnetic 

 intervals in years. 



(1) 1833 



3-3 



(2) 1843 



4-77 



(3) 1856 



4*17 



(4) 1867 



3*35 



(5) 1879 



5*25 



(6) 18^0 



3*90 





Mean .. 4*12 



