THE RAINFALL OF AUSTRALIA. 259 
to date. The chart is divided into columns giving the 365 
days of the year and the horizontal lines across the chart 
give the inches of rain. By plotting each year’s rain track 
and starting at the left hand top, a comparison can be 
made for any day of the separate years. In parts, the 
crossing and recrossing of the tracks looks confusing, but 
by using the final figures of each year, for the traverse, 
the course of any year’s rain track can be followed, thus 
for the year 1860, the two figures 60 are constantly repeated 
to shew its track, and so on. Those days in which no rain 
falls, must, of course, be shewn as a horizontal track. 
The difference in the rain track of 1888 and 1860 is very 
startling. Apparently we have in these years, a minimum 
and maximum rainfall for Sydney; and yet up to 22 July, 
the years 1864, 1867, 1874 and 1900 had a greater rainfall 
than 1860, whilst the year 1890 hada greater rainfall than 
1860 up to 15 November. ‘Taking a period of say 10 years, 
there is a marked similarity in the distribution of rain all 
over New South Wales, that is to say, if a series of years, 
not individual years, give a high rainfall for Sydney, so 
will the same series shew a high rainfall over the State 
generally and vice versa. To shew this, another diagram 
is needed. The black discs on the chart shew when half 
of the year’s total rain had fallen. Generally, it will be 
seen that the first six months of the year has more rain 
than the latter half. This year 1908, however, is one of 
the exceptions; it already shews that the last six months 
must have more rain than the first half of the year. 
In columns below you will see the rainfall for the separate 
months for all years, grouped, and also the monthly fall for 
each year in other columns,—April the greatest, closely 
followed by June, whilst December shews the lowest. I 
think these diagrams are very interesting as bearing upon 
the Water Supply of Sydney. It seems to demonstrate 
