ABSTRACT OF PROCEEDINGS. lxxxiii. 



are two layers of loose bricks arranged to form subdrainage 

 ducts, the whole being contained in a water tight tank 7 

 feet in depth, the floor of which slopes to a central channel 

 leading to the effluent outlet pipe. 



The clear water tank was originally uncovered, and under 

 the influence of sunlight vegetable growths developed 

 rapidly and caused much trouble. The filaments were 

 drawn into the pump suction, found their way into the 

 water reticulation pipes, and choked the strainers of water 

 meters. At certain seasons of the year, the growth was 

 so abundant as to necessitate the cleaning out of the tank 

 every three or four weeks. This, besides being expensive, 

 caused inconvenient stoppages. A roof was constructed 

 over the tank, and light being excluded the growth of 

 aquatic plants ceased. No further trouble from this source 

 has since been experienced. 



The beneficial effect of filtration was shewn by tables of 

 the analyses of storage water. 



Mr. T. W. Kbelb, m. inst. c.b., moved the adjournment of 

 the discussion and the Session then terminated. 



The Third Session opened 19th October, 190 Jf. 

 Mr. S. H. Barraclough in the Chair. 

 Present twelve members and two visitors. 



Mr. J. M. Smail, m. inst. ce., contributed a supplementary 

 paper on "A method of Water Filtration adopted in Western 

 Australia," communicated by Mr. Faulkner, illustrated 

 by drawings of the works. 



The system described in the paper had to be adopted on 

 account of the water carrying so much clay in suspension, 

 which was found to clog an ordinary sand filter in about 6 

 days ; after some experiments a suitable medium was dis- 

 covered in a sort of coarse cloth made up in the form of a 



