THE CLIMATE OF AUSTRALASIA 



The weather cycle thus estab- 

 lished, is not invariable in 

 length, and it does not affect the 

 whole world similarly and sim- 

 ultaneously. The figures above 

 quoted show that the cycle has 

 varied in different centuries from 

 34 to 35 to 36 years. The mean 

 length is given as 34-8 +_ 7 

 years. Moreover, it must be 

 remembered that the variations 

 of any one of the meteorological 

 elements is the result of the 

 action of a complex of varying 

 and opposing agencies. It is 

 inevitable that there will be 

 irregularities, which will be 

 exaggerated in appearance by 

 the artificial divisions of our 

 annual weather records. The 

 calendar year is not altogether 

 satisfactory meteorologically ; 

 the year from spring to spring or 

 from autumn to autumn would 

 give better results than the 

 present system of dividing the 

 southern summer and the north- 

 ern winter between two years' 

 records. We must be prepared 

 for unexplained inconsistencies 

 in the data, and when we con- 

 sider the extreme sensitiveness 

 of the weather to local causes, 

 the surprising fact is that only 



