COMPARISON OF THE RAINFALL OF MELBOURNE AND SYDNEY. 193 



show any actual period of serious drought, being below 

 the Melbourne average only in the exceptional year 1888. 



If we define the term 4 drought' as being the absence of 

 rain over a lengthened period resulting in a serious deficiency 

 of the year's downfall, the people of Sydney are compara- 

 tively in a very fortunate position. To illustrate this point 

 I would say that the rainfall of Sydney during the present 

 year up to date, despite the droughty conditions which 

 existed from about June until the end of October, say 

 roughly four months, has been no less than 28*9 inches 

 as compared with 29*2 inches for a similar period of the 

 previous year. In view of the Melbourne average fall of 

 24*9 inches, why should we speak of a " drought " in Sydney 

 at all? It must be remembered, however, that about one- 

 third of the year's rainfall may happen in the first half of 

 the Australian season — July to December — the remaining 

 two-thirds falling in the second half year — January to June 

 — and a serious irregularity in Sydney during the earlier 

 'dry' season would not be fully compensated by an equal 

 excess happening in the later 'wet' season. The diver- 

 gencies in the rainfall of these two great cities are so 

 striking as to tend to make one careful in formulating any 

 conclusions based on the rainfall experience of either city 

 taken alone. The conditions affecting rainfall are those 

 governing the evaporation of moisture from the sea, 

 modified by the duration and strength of the winds carry- 

 ing the rain from over-sea, and by the temperature of the 

 soil in the areas over which the potential rain clouds are 

 carried. Sydney is a coastal centre, whilst Melbourne 

 occupies an intermediate position somewhat less influenced 

 by coastal conditions. 



Professor Gregory, at whose hands so many of the 

 scientific problems of Australia have received elucidative 

 treatment, in his book published in 1904, "The Climate of 



M— Dec. 4. 1007. 



