NORTH SYDNEY AND DOUBLE BAY SEWERAGE SCHEMES. XXXIII. 



more satisfactory than the first three, and the efficiencies which 

 are given in the above table were based upon this day's results. 



It may be mentioned that when taking these tests with one 

 compressor at 50 revolutions per minute, the plant was practically 

 developing only one-quarter of its full power. 



With the maximum quantity of sewage to be lifted, necessitat- 

 ing both compressors running full speed, the efficiencies would be 

 higher. 



In conclusion, the Author desires to acknowledge the very able 

 assistance and loyal support he has invariably received in the 

 preparation of the designs and construction of the works dealt 

 with in this paper, from Messrs. Millner, Assoc. M. Inst. C.E., 

 and Cutler, Assistant Engineers of the Sewerage Construction 

 Branch of the Department of Public Works. 



For a general 'plan of outfall works see Plate I. 



