yearly Variations of Terrestrial Phenomena and Solar Activities. 9 



the years of maxima and minima of pressure were plotted on the 

 spots-faculae diagrams in exactly same manner as described above 

 for the case of the seismic frequency. The result showed a remark- 

 able fact that all stations may be divided into two distinct classes 

 according as the maxima or minima of the pressure are associated 

 with the small hemispherical difference |i\^— /S'l'^ Among the 

 stations investigated, Jakutsk, Irkutsk, Nicolaevsk, hey, Zikawei 

 ■etc. show maxima, while Tokyo, Hongkong, Manila, Langoon and 

 all Indian stations show minima of pressure for small |iV— aS'|. This 

 remarkable fact harmonizes well with the above conjecture that 

 the small hemispherical difference is associated with the higher 

 continental and lower oceanic pressure. 



The above results confirm the undeniable influences of the 

 difference of activities on the two hemispheres of the sun upon the 

 terrestrial weather and at the same time emphasize the importance 

 of the barometric distribution as the actual cause of earthquakes. 



On the other hand, the number of earthquakes in Jamaica 

 was taken from Maxwell Hall's paper'' and plotted on a similar 

 diagram. It was found that this district belongs to Class I, i. e. 

 the maximum frequency is met with in the years with small 

 hemispherical difference of the solar activities. According to Hall, 

 the seasonal distribution of frequency shows a maximum in 

 winter. Hence it may be supposed that the small lA''— *S'| tends to 

 give winterly character to the barometric distribution. According 

 to Berghaus' s Meteorological Atlas, the winter gradient in this dis- 

 trict is generally greater than the summer one. The yearlj^ pressure 

 at Florida, Texas and Mexico was found to show maxima in the 

 years with small |A^— *S'|, while Newcastle in Jamaica shows 

 minima for the same. This relation therefore corroborates the 

 above results for the Japanese earthquakes. 



Next, yearly numbers of the earthquakes in different parts of 

 the world which were reported in the ' London Times ' and quoted 

 by R. W. Sayles in his note on 'Earthquake and Rainfall, ^^ were 



1) The results of thtse investigations will be given in the ntxt chapter. 



2) Maxwell Hall : Earthquakes in Jamaica, from 1688 to 1919. 



3) E. W. Sayles, Bull. Seism. Soc. America, 3 (1913). 



