RAINFALL AND DISCHARGE OF THE MURRAY RIVER. LXXIII. 
the courtesy of the Government Meteorologists of New 
South Wales and Queensland, the author has been supplied 
with the rainfall returns extending over a number of years 
and he has compiled these records from which the mean 
annual rainfall has been determined. 
To investigate the question of run-off over the entire 
Darling catchment would have been futile, as the lowest 
gauging station at which reliable stream measurements 
have been taken is at Wilcannia, about 500 miles from the 
point where the river joins the Murray. Wilcannia has, 
therefore, been selected as the station from which deduc- 
tions of rainfall and run-off have been made. 
Stream Measurement of the Darling River at Wilcannia. 
The method adopted for measuring the discharge of the 
Darling at Wilcannia was that known as rod floats. The 
range of observations was very extensive, and covered all 
stages of the river from summer level to moderate floods. 
Complete sections of the waterway were taken, and rod 
velocity measurements made at frequent intervals. Daily 
gauge readings have been recorded at Wilcannia for many 
years, and by combining these with the measured discharge, 
a rating table was prepared showing the discharge for every 
inch on the gauge. On this basis the total monthly dis- 
charges werc estimated. It is not claimed that the results 
are as correct as they would have beenif the more modern 
and refined method of current meter observations had been 
practised, but for the purpose of this paper they may be 
taken as well within the bounds of reasonable accuracy. 
Subdivision of Catchment.—The catchment area above 
Wilcannia has been divided into districts—(a) The Murray 
Basin within the State of Queensland. (b) New South 
Wales catchment above Bourke. (c) Area between Bourke 
and Wilcannia. 
As previously mentioned, the records of the Queensland 
rainfall stations have been used in computing the mean 
