HAYES EARTHCyjAKES IN 1 87 1. 1 77 



showing the number of different days in each year on which 

 earthquakes have been reported from 1739 to 1842, and that the 

 largest maxima occurred in the ^-ears of the heliocentric conjunc- 

 tion and opposition of Jupiter and Saturn, with but three excep- 

 tions, and in those cases the inci'ease began in those years, but 

 the maximum was not reached till the following year. I also 

 suggested that these planets induce electric currents w^hich call 

 into action those forces to which the causes of siesmic phenomena 

 are usually ascribed. My subsequent investigations have only 

 tended to confirm the opinion then expressed. I cannot see why 

 there should be any regular periodicity at all, unless the super- 

 inducing cause is outside of the earth itself; and, as it seems to 

 me, it cannot be gravitation, for, if it were, the periodicity could 

 not be so so strongly marked as it is in respect to these two plan- 

 ets, since their effect upon the tides is inappreciable. The phy- 

 sical condition of those two bodies and their exceedingly rapid 

 axial rotation would seem to fit them for exei'ting, in some of its 

 forms, a greater amount of repelling force than any other heav- 

 enly body in our system excepting the Sun. 



iii — 12 June 31, 1873. 



