to the Town of Geelony. 57 



reservoir having no bye-wash proper, therefore, strictly- 

 speaking, the word "bye-wash" is a misnomer, as at 

 present applied by the authorities in connection with the 

 scheme ; it is simply an outlet overflow, constructed at the 

 termination of the embankment. The real bye-wash is the 

 original River Plenty, by which all that the aqueduct cannot 

 receive pursues its onward course to the sea. 



These tables prove one of two things — either that the plu- 

 viameter indicated less than the real Tall, or that nearly all, 

 if not quite all, the rain-fall on the 40,000 acres, found its 

 way towards the reservoir, and would have nearly filled it, if 

 the two-mile aqueduct had been capacious enough to convey 

 it. 



That the whole quantity came down I do not for a moment 

 doubt ; and it arose from the fact of the ground having been 

 thoroughly well saturated prior to the rain now registered for 

 June and July, 1856, thereby proving that heretofore the 

 theoretical allowance of colonial engineers and others for 

 available water is much under the mark. 



I would have it, therefore, inferred, that the per centage 

 as allowed by me for Wormbete is no way in excess, but 

 otherwise scanty, seeing that it is a much more favorably 

 circumstanced gathering-ground, all things considered, than 

 the Plenty. 



Table No. X. 



Showing the proportion of Evaporating Surface of various Home and Colonial 

 Keservoirs and natural Lakes, as compared to their acreable Water-shed 

 in extent : — 



Lake Corangamite 



Lake Colac 



Lake Wardyallock 



Eivington Pike (England) 



Yan Yean 



Wormbete 



One-ninth. 



One-tenth. 



One-eleventh. 



One-twentieth. 



One-thirtieth. 



One-sixtieth. 



In regard to the purity of the Wormbete reservoir waters, 

 it should be borne in mind that from the time on which they 

 are condensed on the surface until they are impounded in the 

 reservoir there are no lagoons to fill, no sedgy marsh lands, 

 no extensive swamps to pass over, absorbing much, dis- 

 colouring the residue, and creating vegetable poison; no 

 fallow lands or agricultural district to impregnate more or 

 less by the impurities which they contain, and which may be 

 gathered up by the waters passing over them ; no contami- 



