ANALYSIS OF SOLAR RECORDS 81 



Cycles in Fritz's Auroral Records 

 Maxima of period named 



577 

 585 



809, 840 



1096, 1205, 1263, 1349 

 1349 



major max. 1561; lesser max. 

 1568 (possible Hellmann cycle) 



It will be noticed that we have here abandoned the maxima assigned by 

 Fritz in an 11.1 year cycle and endeavored to find maxima that have intrinsic 

 evidence of being sunspot maxima. One might possibly accept A.D. 577 on a 

 period of 12.4 years but might feel doubtful about 585 on a period of 15.2. 

 A.D. 809 and 840 might occur on a 10-year period but they are not convincing at 

 all. A.D. 1096, 1205, 1263 and 1349 on an 11.8-year period seem satisfactory, 

 but a maximum on a 13.8-year period does not seem satisfactory. The 11.8 

 period from 1432 to 1635, with a major maximum in 1561 and a lesser maxi- 

 mum in 1568 seems to be giving us real information by suggesting a Hellman 

 cycle which agrees with the tree records of northern Arizona and deserves 

 full consideration. 



