118 WATER BTJPPLY TO SYDNEY i;v &RA.YITATIOF. 



Geelong, took eighteen months in building, and was made at a 

 much greater expense. 



1 have much pleasure in presenting to this Society the valuable 

 plans and descriptions sent to me by the Engineer-in- Chief of the 

 Victorian Waterworks, and which I would suggest should be 

 attached to this paper as an appendix to the same (for which they 

 were kindly and specially prepared by Mr. Gordon). My belief 

 that this extra information from so able an engineer, when coupled 

 with the published description of Bitter's similar work in Switzer- 

 land, may go far to school our minds into the knowledge that 

 the apparent costliness of these works is as nothing compared 

 with the great advantages that would accrue to the public from 

 their adoption, and that by making people familiar with the idea 

 of costly works they will at last come to consent to their being 

 entered upon. AVith such hope before me, I will leave the sub- 

 ject in other hands, and retire, from it myself. 



APPENDIX. 



" The Stony Creek dam for the Geelong "Waterworks in Victoria 

 was designed by Mr. Gordon, the hydraulic Engineer-in- Chief 

 for the Waterworks of that Colony. This gentleman kindly fur- 

 nished me with the plans and with the following descriptions of 

 the work. 



The dam is on the method introduced by the French engineers, 

 MM. Graef and Delocre, from whose designs the great dam at 

 jfurens was built. It is known as the system of equal pressures, 

 it being so calculated that the pressure at the rear surface shall 

 not exceed and not fall short of a certain pressure per square 

 foot, when the reservoir is full, nor at the front surface when it 

 is empty. In this case the limit is 8,000 lbs. to the square foot. 

 The top, however, and for some distance down it, is theoretically 

 too thick ; it ought to come to a sharp edge at the water line, 

 which would be inconvenient. 



It is built of concrete, made of sandstone, metal, sand, and 

 Portland cement. The following proportions were found the 

 best : — • 



2 metal, 3f parts ; screenings, 1| part ; sand, 1^ part ; cement, 

 1 part. 



The contents are 5,096 cube yards. The cement and saud were 

 first mixed and made into mortar, and the other ingredients were 

 then added, the whole being constantly turned over in a mixing- 

 trough similar to a " buddle," driven by horse-power. The sur- 

 faces are plastered with cement mortar. 



The greatest height is 67*6 feet, the height above the scour, 

 which is near the old creek level, is 53 feet, and the outlet is 9 

 feet higher than the scour. The thickness at the level of the 

 scour pipe is 38 feet, and at the top, under the coping, 2 feet 



