I 



1 wave of rainfall recurring at intervals of 12-5 years (Hatchins* "cyclical mitigation "} 



i i 



A_ 



1 wave of rainfall recurring 



at intervals of 9'5 years (Hutchins' " storm cycle " 

 1 i 



i l ii i i 



3 waves of rainfall recurring at intervals of 11-11 years (Wolf's "sunspot cycle"): 

 1. Hutchins' " sunspot rains." 2. Hutchins' " lag rains." 







I 26-6 f 



Drought of sunspot minima. 



I 24-7 



Drought of sunspot minima. 



Observed waves of rainfall, Ottawa, 1870-89. 



O 



r-^ 



to 



i 



CM CO 



r^. r- 



* to co 



CO CO Or-CMCOTt-lOCDf^-CO CO 

 I s ** ^- CO CO CO CO GO CO CO CO CO CO 



o 



CO 



co 



