PUMPING MACHINERY OF THE WATER AND SEWERAGE BOARD. LIII. 



time we have seen the centrifugal pump advance from 

 being only an expensive steam eater capable of raising 

 large quantities of water to a moderate height into an 

 economical pump, and also suitable for practically unlimited 

 heights, it only needing multiplication of the number of 

 pumps in series to give any height required for the delivery 

 of water or other fluid, and the example of a high lift single 

 stage pump at Grown Street station and the series pump 

 at Ryde show that those responsible for the water supply 

 of Sydney are keeping up to date with the most modern 

 types of plants. Although in first cost centrifugal pump- 

 ing machinery has a great advantage, yet I cannot think 

 that they will ever have the life of good compound beam 

 pumping engines. I understand that the compound beam 

 pumping engines designed by the late Dr. Pole, f.r.s., and 

 built by Simpson & Co., in 1851, are still working at the 

 Lambeth and Chelsea Waterworks at Surbiton, these 

 engines with their 8 feet stroke, making 16 revolutions per 

 minute, often working for two months without a stop, 

 have I believe, proved themselves less costly for mainten- 

 ance than any other type of pumping engines. The solid 

 foundations, direct lines of thrust and solidity of construc- 

 tion, ensuring economy in maintenance, and as regards 

 fuel consumption, even when the low boiler pressure (40 lbs.) 

 at which they have worked is considered, they have 

 given a highly satisfactory]result. 



Subsequent to 1851 many other beam engines were built 

 by the various makers for pumping water, and with the 

 increase in pressure the steam consumption per indicated 

 horse power was reduced very considerably. A beam 

 engine, built in 1885, with only 60 lbs. boiler pressure, used 

 as little as 15*12 lbs. of dry saturated steam per indicated 

 horse power per hour. Earlier than that, in 1881 a beam 

 pumping engine had been constructed using 11'81 lbs. of 



