782 PROCEEDINGS OF SECTION H. 



3rd. To provide means for discharging the effluent at 



all states of the tide. 

 4th. To provide means for dealing with the sludge. 



Now, if we compare these necessary, and these probably 

 necessary, provisions to be made in order to carry out the 

 precipitation process with the necessary and probably 

 necessary provisions to be made in order to carry out an 

 irrigation scheme, we shall be able to make some calculation 

 as to the relative cost of the carrying out and of the yearly 

 working of the two systems. I must premise that I take 

 the case of Melbourne to base this calculation upon, as in 

 Mr. Mansergh's repoi't there are the needed estimates of 

 cost as regards his irrigation scheme. I should further 

 premise that I take the part of his scheme that is to be first 

 carried out as being based on actual present requirements for 

 pumping, sewer construction, &cc., with a certain provision 

 for the future, but not the full provision of his complete 

 scheme — though this latter would have shewn a still greater 

 divergence between the relative cost of the two systems. I 

 should also say that, as in the smaller scheme the expenditure 

 at the pumping works is reduced by two-thirds, I presume 

 the quantity of sewage to be pumped is to be equally reduced. 



Three of the necessary ]irovisions for an irrigation 

 scheme were shewn to be the farms, the outfall sewers, and 

 pumping power. Mr. Mansergh's estimate for the farms 

 is £312,000 



For the outfall sewers 1,333,000 



For so much of the pumping stations as is 



to be now done 219,000 



For the proportionate share of the contingencies 



upon the above 186,000 



Making a total for the work exclusively 



needed for the disposalof the sewage... £2,050,000 



The yearly cost of the system on Mr. Man- 

 sergh's estimate would be — 



Repayment of capital and interest on above 



amount £87,400 



Proportion of wages, staff, &c. ; also half- 

 cost of work at pumping stations 1 1 ,100 



Total yearly cost £98,500 



