THE WEATHER CYCLE 69 



CHAPTER V. BRUCKNER'S PERIOD AND 

 THE SUN. 



The existence of the 35 years periods, which 

 Bruckner has established with such a convincing 

 array of evidence, is all the more remarkable 

 because it is in agreement with a long period 

 variation in the sun, which was unsuspected 

 when Bruckner wrote his monograph. Bruck- 

 ner was so convinced that his 35 years' cycle 

 must be caused by changes in the sun, that he 

 turned to solar records, confident that he would 

 find in them some variation, of which the 

 variation of the weather on earth was an echo. 

 At the time of his work, it was believed that, in 

 addition to the n x / 9 years sun spot variation, 

 there was a longer sun spot cycle, of which the 

 length was 55 years. That cycle was claimed 

 by Wolf. Bruckner searched the weather 

 records for any trace of this 5,5 years period 

 His elaborate data showed that the weather 

 varies in a 34-5 years' cycle ; and as astronomers 

 told him that the sun spot variation was 55 

 years, he logically accepted the conclusion that 

 sun spots had no influence upon the weather. 

 Bruckner therefore predicted that some other, 

 and then unknown variation of the same period 

 as his own, would be discovered in the sun. 

 Bruckner's confidence has been justified ; and 

 the main argument against any relation between 

 sun spots and the weather has been removed. 



