WATER SUPPLY. 863 



SO that the rate of eight-pence is no criterion of the actual 

 charge on the consumer. 



Many of the rural townships in Tasmania obtain their 

 supply of water directly from the river flowing through or 

 near them. In the majority of cases the water is pronounced 

 good and wholesome. There are instances, however, where 

 objections have l)een raised to a scheme for obtaining a 

 permanent supply from sncli a source, owing to the water 

 ajipearing turbid and discoloured during a heavy " freshet " 

 or flood. In its normal state it is pronounceably clear, and 

 to condemn it on account of the above fact is a hasty judgment, 



A writer on this subject remarks, " Brooks and small 

 streams are not desirable soui-ces of water supply ; the quantity 

 of organic matter they contain in comparison with the 

 quantity of flowing water in them is greater than that 

 contained in the water of other sources such as rivers, springs, 

 moorland tracts of ground, and deep wells." As to rivers, 

 running water contains free oxygen absorbed from the 

 atmosphere, and the more so where it has a quick motion 

 over a rough bed, which causes its surface to be broken up, 

 and exposes a greater numljer of particles of water to the 

 atmosphere than where the motion is slower over a smoother 

 bed. 



It is a matter of common observation that the discoloration 

 of rivers by the polluting mattei's poured into them from 

 populous places gradually fades away, and that at some con- 

 siderable number of miles below, if no other pollution takes 

 place on the way, the water is clear, and in some cases quite fit to 

 drink. The difficulty is to ascertain in what distance or in 

 what time this ett'ect take place, and there is nothing but 

 supposition to go by in estimating at what distance from the 

 polluting source water may safely be taken for domestic use 

 lower down the river. It cannot very well be proved that 

 they are wrong who advocate a river source for a supply of water 

 even when it is well known that the water is contaminated 

 higher up the stream. 



The strongest argument in su])port of such a course is 

 found in the want of proof that the water is injurious to the 

 health of those who constantly drink it. 



On the other hand, as to the disajipearance of colour by 

 long-continued flow, it is proved positively that water may be 

 quite bright and yet contain matter in solution which dis- 

 qualifies it for domestic use. 



Another point worthy of passing notice is the utter 



