1XXX1V. ABSTRACT OF PROCEEDINGS. 



tube 6 feet long and 20 inches diameter, the cost of which 

 amounts to 3 shillings each. Firstly the water is passed 

 through an aeration, then treated with lime and then passed 

 into large settling tanks from whence it is conducted to 

 the filter cloths through a system of pipes. The filter 

 clotlis are so arranged that every part is open to view, and 

 are exposed on inside and outside to atmospheric influence 

 in such a way that the thin film of water flowing down the 

 clotlis is thoroughly oxidised. The cloth filter has the 

 advantage of requiring less space than the sand filter as 

 from the way in which it is arranged it presents 27 feet of 

 filter surface to each 6 feet of floor space, and owing to its 

 ability to stand a greater pressure than the sand filters, 

 twice the quantity of water may be put through, so that a 

 cloth filter of a given floor area has nine times the capacity 

 of a sand filter. Another advantage is that the cloths can 

 be replaced after cleaning much quicker than a sand filter 

 can be scraped and restored, and further, it regains its 

 maximum efficiency of filtration much quicker than sand. 



The cost of construction is low, and an expenditure of 

 £6,200 will be sufficient to deal with 5 million gallons 

 per day. The cloths last about 1 month when filtering 

 water from the bores, but when filtering water from the 

 ranges they last 6 months. 1,500 superficial yards of filter 

 area are completely removed out of the tanks, washed and 

 replaced by 4 men in 8 days ; the cost of maintenance 

 including wages, cloths, lime and repairs amounted to 0*6 

 of one penny per 1,000 gallons for the last two years. The 

 experiments of Massachusetts Board of Health have demon- 

 strated that the colon bacillus and the typhoid bacillus in 

 polluted water were rapidly destroyed by sunlight on 

 exposure of 30 to 60 minutes, and when the water was spread 

 out into a thin film the time required for their destruction 

 was only 15 minutes. The analyses of the water filtered 



