CHAIRMAN’S ADDRESS. XXXIX. 
If we are wise, therefore, we should not rest satisfied with 
Cataract Reservoir, large as it is; but endeavour to fore- 
cast requirements, and ascertain what our position will be 
in the near future. 
Forecast of the Seasons.—The diagram of the Sydney 
rainfall is the record of our experiences of the weather 
during the last 76 years. If we consult it we shall see that 
there have been two periods of 14 years accumulated loss 
of rain below the mean, and one of 9 years. It is true that 
in the period from 1893 to 1907, there was a break of two 
years, viz., 1899 and 1900, when the rain was above the 
mean; but all the other years were below the mean, and the 
accumulated loss of rain over the whole period of 14 years 
was greater by 8°67 inches than during the 14 years period 
from 1845 to 1859, when breaks occurred in 1848, 1855, and 
1857, these years being above the mean, and all the others 
below it. During the drought of 9 years from 1879 to 1888, 
only one year, viz., 1887 was above the mean. We may 
reasonably anticipate therefore, that we have reached the 
minimum, and may look forward to five or six years of rain- 
fall above the mean, such as we had following the termin- 
ation of the droughts in 1839 and 1888. It is possible, of 
course, that instead of arun of wet years similar to these, 
we may be about to experience weather such as we had from 
1859 to 1872, when after two years of good rainfall above 
the mean, there were two below it, followed by three 
periods in succession of one year above the mean, followed 
by two years below it. 
Estimate of Population and Consumption of Water.— 
Assuming however, that we havea run of five years of 
good rainfall above the mean, let us see what our position 
would be during that time, and at the end of the wet period. 
The reservoirs, after the first heavy rainfall, will be full, 
and would practically remain so until 1912-13. If the rate 
