XIV. J. G. S. PURVIS. 



tardy, and various methods were tried with a view to facilitate 

 the entry of the nitrate into the drains. With this object in view 

 pipes were inserted in the line of drains having side inlets, these 

 inlets being closed with wove wire gauze discs having 3,600 meshes 

 to the square inch. These discs acted very well for the time, the 

 rate of discharge being very much increased, but after about 

 twelve or eighteen months they perished and required renewing. 

 The price of a new disc together with the cost of inserting it was 

 found to be too expensive, so another system was tried, and after 

 about three years' experience, has been found to work admirably 

 so far as rapidity of disposal is concerned. 



The sewage falling into the Western System is purely domestic 

 sewage, derived from the whole of the Western Suburbs as far as 

 Strathfield, which on its arrival on the farm at Arncliffe passes 

 through screens, thus ridding it of all rags and other coarse solids 

 which would otherwise only choke the distributing valves and pipes. 

 The total area of land over which this sewage is distributed 

 amounts to 118 acres, the whole of which is used as filter tanks. 

 Seventy-three acres have been provided with underdrains consist- 

 ing of unglazed porous pipes of the agricultural pattern, having 

 coir fibre mat joints, and as this system of jointing is the only one 

 now adopted, I will describe it in detail. 



Plain unglazed pipes 6 inches diameter, of the agricultural type 

 are laid with their ends 2 inches apart, and around the open joint 

 a coir fibre mat 9 inches wide is wrapped and tightly sewn on, 

 and on the joint thus made a pad of loose fibre is laid, the whole 

 joint then being surrounded with about one cubic foot of coarse 

 sand. The sewage, after percolating through about four feet of 

 sand, passes through the mats and enters the pipes. Each pipe 

 is two feet long, and altogether about twelve miles of drains 

 have been laid, which means that nearly 32,000 mats have up to 

 the present been utilized. 



The system of under drainage at this end of the Sewage Farm 

 consists of large central mains 18 inches diameter glazed stone- 

 ware pipes, having cast iron pipe outlets discharging into Muddy 



