XXXII. J. DAVIS. 



Each day before starting a man was placed at each ejector 

 station to count and keep tally of the number of times the ejector 

 discharged, from the time of starting to the finish of each trial ; 

 and, the capacity of ejectors being known, the number of gallons 

 of sewage discharged by each station could be readily computed. 

 From this and the total left, the work performed was obtained. 



The compressor was kept going at a uniform speed of 50 

 revolutions per minute, which maintained an average air pressure 

 of 20 lbs. per square inch in the receivers. 



Indicator diagrams were taken off the compressor at intervals, 

 in order to obtain the average indicated horse power developed. 



On starting the plant each day the reading of the Watt meter 

 at Double Bay station was taken when the air pressure had risen 

 to 15 lbs. per square inch, and simultaneously a reading was 

 taken of the Watt meter at Rushcutter's Bay generating station. 

 Readings were also taken of both Watt meters at the end of the 

 day's trial. By this means a record was obtained of (a) the 

 electrical energy which left the generating station at Rushcutter's 

 Bay (b), the loss of energy in the line, and (c) the energy used by 

 the motors at the Double Bay power station. 



The loss of efficiency, due to drop in temperature, was obtained 

 under normal working conditions by taking the temperature of 

 air leaving the compressor and at each ejector station. 



On the first day the trial was taken for a period of two hours, 

 on the second day two hours, and on the third day one hour 

 twenty-five minutes. 



On each of these days it was found that Nos. 3 and 4 stations 

 were pumped out shortly after starting, as there was not 

 sufficient sewage flowing into them to keep them working 

 continuously for the same period as the other ejectors. 



On the following day the flushing stations and a couple of 

 hydrants were turned into the sewers, and by that means a 

 constant flow was maintained, enabling all the ejectors to work 

 continuously during two hours and twenty minutes. The 

 conditions, therefore, under which the latter test was made were 



