WATEK SUPPLY TO SYDNEY BY GRAVITATION. 117 



mons by various able engineers, in the persons of Hawksley, Eaw- 

 linson, and Bateman. 



I lately bad tbe pleasure of meeting Mr. G\ Gordon, of the 

 Victorian Water Supply, during a recent visit to Melbourne. 

 This gentleman not only deputed one of his own officers at the 

 Tan Yean Waterworks to show me everything connected with 

 that fine supply for and delivery into Melbourne, by its embank- 

 ment of 48 chains with maximum depth of 1,200 acres of water 

 at 25 feet, but he also most kindly undertook to accompany me 

 afterwards to the western waterworks at Malmsbury, 63 miles 

 from Melbourne, known as the Coliban Waterworks. Prom 

 thence he took me on still further to witness the interesting 

 method of crossing the supply waters for Castlemaine over the 

 valley of the Back Creek by means of the so-called inverted 

 syphon composed of a 36-inch cast-iron main, which conveys the 

 channel waters underground across a valley that is 114 deep, and 

 nearly half a mile across from water-level to water-level. The 

 Castlemaine end of the pipe is depressed 6 feet below water-level, 

 to admit of a free outflow of the waters into the channel. 



I need scarcely say how interesting these inspections of the Vic- 

 torian Waterworks were to me, whilst made under such very 

 favourable circumstances. I cannot speak too gratefully of Mr. 

 Gordon's kindness in affording me such instructive and pleasurable 

 advantages. Mr. Gordon favoured me with a complete set of his 

 own and predecessors' official reports on Water Supply, which I 

 have now the pleasure to present to this Society, after having 

 gleaned much information from them in connection with my own 

 present work and attempt at usefulness in same direction. 



I have also to record another very obliging act of kindness of 

 Mr. Gordon's in his having since furnished me with working plans 

 of the cement concrete dam that he has recently built at Stony 

 Creek for the Geelong Water Supply. These plans are also 

 accompanied with descriptions of the method of constructing that 

 dam, together with the cost of the work, &c, all of which I am 

 authorized by Mr. Gordon to use in connection with the publi- 

 cation of my present paper. I may add that, on presenting Mr. 

 Gordon with a copy of my water-supply map, together with a 

 copy of the paper containing the translation of Delabar's paper 

 on Eitter's great Freiburg Waterworks, he exclaimed with pleasur- 

 able surprise when he saw the diagram showing the section of 

 Eitter's cement concrete dam, inasmuch as he had not been aware 

 that any one else had made a similar embankment, although his 

 own design is on the principle of the building of the Furens 

 dam, though slightly modified. Mr. Gordon's cement concrete 

 dam at Stony Creek was commenced before the similar embank- 

 ment was finished at Freiburg. The Freiburg dam took two 

 years to complete, whilst the much smaller one at Stony Creek, 



