XXXII. J. HAYDON CAUDEW. 



together systematically and comprehensively over the 

 whole of this and the adjoining States, we cannot solve the 

 riddle of our western rivers and what becomes of the rain- 

 fall. At the present the whole of our deductions are 

 largely based upon assumption and guess work, as has been 

 admitted, and in the author's opinion, the discrepancy 

 existing between the rainfall and discharge for the rivers 

 aforesaid has never been satisfactorily accounted for, and 

 until a complete system of hydrographical observation is 

 established for the whole of the basins of these rivers it 

 never will be possible to devise a system of irrigation and 

 conservation until these questions are scientifically dealt 

 with and solved. On the other hand the possession of such 

 knowledge regarding these rivers would enable the engineer 

 to project with confidence any system of irrigation, and 

 would enable him to determine with accuracy the magni- 

 tude of the works required, therefore the hydrographer 

 should precede the engineer, and as his work requires time 

 for maturity, he should have a long start of the engineer. 



One of the important considerations in designing irriga- 

 tion works and especially storage reservoirs, is the maximum 

 amount of rainfall that may occur in any period of time ; 

 great floods are the immediate result either of the sudden 

 melting of snow, or of heavy rainstorms coming perhaps 

 after a period of wet weather when the ground is fairly 

 saturated, and statistics showing the rainfall in 24 hours 

 are often insufficient to give a safe estimate of what may 

 be precipitated in sudden storms. Mr. Russell records a 

 rainfall in 24 hours at Arnold Grove, 28th May, 1889, of 

 11*13 inches, and again 10*08 inches on 20th March, 1892, 

 which in the first instance represents 26°/°, and in the second 

 instance 24f° of the mean annual rainfall ; again at Albion 

 Park on the 8th February, 1895, he records a fall in 24 

 hours of 10 inches, or nearly 22°/° of the annual rainfall ; an 



