302 



SEWAGE AND ITS PURIFICATION 



7. Simplex Spreader (Ames-Crosta Sanitary Engineering 

 Co.). A central pillar supports a weatherproof cap running on 

 ball-bearings and supporting the arms. Oscillation is prevented 



by adjustable guide rollers fixed on the underside of the bucket, 

 which revolves with the arms (Fig. 49). The guide rollers run 

 on a machined surface on the central pillar. The joint between 



