DISTRIBUTION AND DISTRIBUTORS 



301 



and more massive description than other makes, and con- 

 sequently the first cost is also greater, but there appears to be 

 no doubt that, owing to the equality of distribution, a greater 

 average rate of flow can be allowed, and a higher class effluent 

 secured. The makers con- 

 tend that the combinsd 

 cost of filter bed and dis- 

 tributor to produce a given 

 standard of effluent from 

 a given volume of sewage 

 is less if this distributor be 

 used than with any other. 

 Two forms of the dis- 

 tributor are given in 

 Figs. 47, 48, the latter 

 representing an equally 

 efficient, but less costly, 

 form than the former. 

 The sewage flows from a 

 central standpipe along 

 a main trough to the ex- 

 tremity of the rotating 

 arm. Alongside the main 

 trough (which is supported 

 by lattice work) runs a 

 small subsidiary trough, 

 which is subdivided into 

 compartments. Each 

 compartment is connected 

 with the main trough by 

 a port-hole, the size of 

 which varies wdth the dis- 

 tance of the section from 

 the centre of the filter 

 bed. The sewage over- 

 flows from the subsidiary 



troughs on to the filter bed. The subsidiary troughs are each 

 fitted with adjustable weirs, and drip points coming close to the 

 surface of the bed. The first cost per square yard of area 

 covered has been found to lie between that of the Barker's 

 Mill type of distributor and the fixed type of distributor. The 

 sizes made are for ^ acre beds and upwards. 



Fig. 49. — "Simplex" Spreader. 



