L. A. B. WADE. LXXIII. 
rainfall and the discharge of that fall by the flow in a river, 
so that information is also required on such important 
points as evaporation and seepage. At the same time the 
hydrology of the subterranean supplies should be studied, 
so that all the water resources of the State shall be properly 
exploited. Along with these should go asystematic explor- 
ation of the country for sites where it would be possible to 
store water. 
The compilation of this voluminous information has been 
in progress since 1884, when some gaugings of the flow of 
the rivers were taken. The work has been continued up 
to the present time, and will have to be carried on for many 
years to come. The discharges of high floods must be 
obtained before an engineer can design works with any 
confidence in their stability, and such floods sometimes only 
recur at long intervals. The periodic alterations in the 
courses of the western rivers also render repeated observa- 
tions necessary. 
Gauging the flow of the rivers is then, the most important 
hydrographical work in connection with water conservation 
in this State. Stations have been set out on all the prin- 
cipal rivers, and daily readings are taken at 35 of them. 
Complete discharges have been taken at some of them, and 
the remainder are being taken at every opportunity. A 
detailed account of this work has just been read before this 
Society, the position of the gauging stations is shewn on 
this map. 
The discharges having been calculated for every foot of 
rise, a curve is drawn shewing the discharges corresponding 
to the height of the water. The total discharge for any 
period can then be obtained by keeping a record of the 
heights of the water-surface during that period. In this way 
the maximum, average and minimum yearly discharges can 
be obtained. The published records of rainfall give no clue to 
