260 



Remarks on the principal Rocks 



reservoir, it is only necessary to assume sixteen inches for 

 each of the three summer months, therefore, Di\ Davey has 

 allowed a large deduction from the true evaporation, to 

 compensate for the extent of the reservoir, or any other 

 accidental cause that might operate to retard the evaporation 

 from the surface. 



What possible reason, or excuse, then, can be given for re- 

 jecting Dr. Davey's estimate of nine feet ? According to my 

 judgment the conclusion is irresistible that his estimate is 

 confidently to be depended on, and I feel warranted in de- 

 ducting the three feet four inches from Mr. Hodgkinson's 

 estimate, which is equivalent to supply 90,909. 



Having thus stated the points of difference between myself 

 and Mr. Hodgkinson, and Avhich constitute the data on which 

 we depend for our water supply, and having shown that they 

 are not based on correct or scientific principles, and are, 

 therefore, unworthy of your confidence, and that, on a 

 thorough investigation of the subject, there are no data to 

 show that there will be any Avater for the city derivable from 

 Yan Yean, I have little to add. 



I shall submit, therefore, that the Philosophical Society has 

 now a very important duty to perform; a duty to themselves, 

 as the interpreters of science in this colony; a duty to the 

 Grovernment and the Legislative Council, who look to them 

 for a scientific opinion to aid them in the decision of the 

 question, if it be proper to allow the Yan Yean works to be 

 proceeded Avith ; and a duty to the public, Avhose health, and 

 comfort, and pecuniary interests are so seriously involved in 

 the success or failure of the Yan Yean Reservoir scheme : 

 and I trust that the Philosophical Society Avill no longer 

 hesitate to pronounce an opinion on the subject. 



Art. XXI. — Remarks on the favourable Geological and 

 Chemical Nature of the principal Rocks and Soils of Victoria, 

 in reference to the production of ordinary Cereals and Wine. 

 By Clement Hodgkinson, Esq., C. E., Survey De- 

 partment. 



Having visited the four principal Austrahan Colonies and 

 been connected with agricultural pursuits in New South 

 Wales, I have long held the opinion that Victoria will 

 eventually produce more wheat and wine than any other Aus- 

 tralian Colony; partly, because this territory contains the 



