PREFACE. 



WHEN invited to deliver the Presidential Address to the 

 Geographical Section of the Australasian Association for the 

 * Advancement of Science as an evening lecture, I thought it 

 advisable to choose a subject of more general interest than 

 that which I had previously selected. Meteorology is the 

 branch of geography in which, at present, the widest interest 

 seems to be felt in Australasia, and in which well directed 

 research promises the richest reward. I accordingly 

 resolved to attempt to explain the basis of hopes for the 

 possibility of long distance weather forecasts, and to suggest 

 some lines of research, which must be undertaken before 

 Australasia can secure the incalculable benefits of such 

 foreknowledge. Success in this work largely depends on the 

 existence of a permanent weather cycle, which is now well 

 established, and has only so long escaped recognition^ 

 because, owing to its dependence on changes in the sun, its 

 length is variable, and it inevitably produces contrary effects 

 in different geographical areas. 



This cycle does not offer us any simple direct evidence 

 as to the nature of the forthcoming seaspns ; for it affects 

 the weather of the continents mainly by causing changes in 

 the circulation of the oceans. Now we know that ocean 

 currents vary from year to year, we can understand how the 

 actual irregularities in the seasons are fully consistent with 

 the obvious oceanic control of the climate of the lands in 

 the southern hemisphere. As these irregularities are caused 

 rpy processes which take a year or more to run their course, 

 we have the means of watching in one year the evolution of 

 the weather we shall experience in the next. 



The problems of long distance weather forecasting may 

 be solved by two methods, each applicable to special areas. 



