DISTRIBUTION AND DISTRIBUTORS 



295 



3. Mather and Piatt, Ld., Manchester, supply a Patent 

 Revolving Spreader driven by the head of sewage through a 

 turbine at the centre of the bed (Fig. 44). The arms are open 

 troughs, perforated along the bottom of one side of each. 

 This arrangement is easier to clean than perforated tubes. 

 The Spreader is hung from a cast-iron standard, and in the 

 larger sizes it is found desirable to steady the outer end of each 

 arm by guide wheels running on a circular rail track. Trough 

 arms are more affected by wind than tubes, but with outer rails 

 a motor can be added for driving during high winds. It is 



Fig. 43. — Candy-Whittaker Distributor at Bedford. 



always desirable to work this form of distributor with automatic 

 flushing gear. 



4. Adams' Hydraulics, Ltd., Yorks, make several forms of 

 revolving Distributors. The " Cresset " differs from others 

 mainly in the air-lock water-seal between the fixed standard 

 and the revolving body, to which the spray arms are connected 

 (see Fig. 45). A fixed tank has an inner division in which the 

 revolving body rotates, and an outer division which when filled 

 with water develops an air-lock between it and the revolving 

 body, and thus prevents the escape of the sewage between 

 those two portions. The whole weight is carried by a cross- 

 head on the top of the central column. At Derby there are 

 18 *' Cressets," each 100 ft. diam., at Birmingham one 120 ft., 

 at Hurlford five of 40 ft, and smaller sizes are made down to 

 10 ft. diam. Exclusive of supply pipes, valves, or flushing 



