58 



H. I. JENSEN. 



Carve showing Eruption Frequency in a Sunspot Period. 



Fig. 2. 



The two curves just given comprise all the disturbances 

 since 1810 given in my list. Hence they can be called 

 curves of mean earthquake and eruption frequency during 

 a sunspot period, being the mean curves for a period extend- 

 ing over 90 years. 



Taking eruptions and earthquakes together, we get the 

 following curve :— 



Sunspot Minima and Total Volcanic and Seismic Activity Curve. 



e/> 



V* 









iMtyt,. 











a 



,00° , ^— -f f f f f f j 



<]0 



So 

























7° 



/■> 























A 





















50 



4c 

 30 





















20 



to 



























Fig. 3. 



