LXII. R. T. McKAY. 
CAVAN 
September—Bad spring, all creeks and gullies dry. December 
—Good rains during this month; 1902 has proved one of 
the driest years on record here. 
February (Summer)—Never saw river so low before. 
HometeigH— March 13th—Terrific hail-storm lasting 45 minutes, 
hailstones measured 5} inches in circumference, and remained 
in places on ground for over two weeks. 
November 12th and 13th.—Continuous red dust 
storm, lasted upwards of 40 hours. 
(QUEANBEYAN 
Stream Gauging.—The most accurate and precise method 
of determining the run-off of a catchment is by actual 
gauging of the stream. Observations in connection with 
the discharge of the Murrumbidgee at Gundagai, extend- 
ing over a number of years, have been tabulated by the 
author, and the results shewn in diagrammatic form. 
Velocity measurements have been made at frequent stages, 
with the latest type of current meter, and in combination 
With daily gauge readings, a rating table has been compiled 
showing the discharge for each inch on the gauge. Occas- 
ionally the river rose to higher stages than those at which 
current meter observations were made; the discharges 
corresponding with these unusually high levels have been 
deduced, partly by producing the curve of volumes, and 
partly by applying suitable velocities to the areas of water- 
way over the banks of the river. 
To determine the run-off in inches of the Murrumbidgee 
catchment at Gundagai from the measured discharges, the 
following formula has been used: — 
I = Depth in inches over catchment. 
D = Discharge in cubic feet per annum 
ee AT 28% & = D 
then 500 x 640 ~ 79009 X 144 = 9595 sannnmee 
Let Dy = Discharge in millions of cubic feet per annum 
Then I = —2“_= p, x -00005186 
19283 
