122 Transactions. — Miscellaneous. 



organic forms, chiefly of a low type of animal life, are fomid also. The 

 most careful artificial filtering fails to free the water entirely from these 

 organisms, some of which are now regarded as the probable source of many 

 diseases. Filtering certainly fails to eliminate the germs ; that is to say, 

 such artificial filtering as is possible on a large scale, such as that of a 

 water supply. But what art cannot do, nature does with unerring certainty, 

 for microscopic examination shows that the water from deep strata is per- 

 fectly free from every form of organic life. It must be remembered also 

 that the vast natural filter-beds which he between Invercargill and the 

 Hokonuis do their work without trouble or interference, and while perfect 

 in their action, are not a source of expense. I therefore claim for the 

 subterranean supply the double advantage of abundant quantity and perfect 

 purity. 



The quantity and purity being taken for granted, it has still been 

 objected to this proposal that the expense of pumping, and the difficulty of 

 obtaining a sufficient pressure for extinguishing fires, render it inferior to a 

 gravitation scheme. Without now going into details, I may remark that 

 the question of expense is one which can easily be settled by calculation ; 

 and I fearlessly assert that the expense of pumping will be but a mere 

 fraction of the interest on cost and the maintenance of thirty miles of 

 iron mains. 



It should be noticed that the pumping scheme has the advantage of being 

 capable of expansion, at no great expense, exactly as the wants of the town 

 increase. "When one shaft is no longer sufficient, another at a small 

 distance can be added, and the supply doubled, and so on as required. Or 

 should it ultimately be decided to adopt a gravitation scheme, this would 

 not stand in the way ; for, with the single exception of the pumping 

 machinery and shaft, everything else in the town service is exactly the 

 same as that requked for the gravitation scheme, and could be utilized 

 without the slightest loss or additional expense. 



On aU these grounds it appears that the subterranean sources of supply 

 are worthy not only of more attention than has hitherto been bestowed 

 upon them, but of a serious practical trial. The expense of a trial-shaft 

 would not exceed £200, including hire of engine and pumps. The question 

 of quantity would then be for ever settled. 



