PUMPING MACHINERY OF THE WATER AND SEWERAGE I30ARD. XLIX. 



information. He felt more inclined to criticise the criti- 

 cisers than the paper. He had represented the contractors 

 at the tests of the HatJiorn-Davey pumping engines both 

 at Marrickville and at Spottiswoode, Victoria, and could 

 vouch for the accuracy of the figures. They had been 

 carefully checked at Marrickville, by the representatives 

 of the Board of Water Supply and Sewerage, Sydney, and 

 at Spottiswood by the representatives of the Melbourne 

 Board of Works. Mr. Selfe was under a misapprehension 

 as regarded the type of engine in use at Spottiswoode. The 

 engine in question was a triple expansion vertical engine, 

 operating direct on to the pumps, as is the practice of high 

 class marine engines, and of course, very high efficiency 

 indeed could be expected from such a pump. As a matter 

 of fact the steam consumption measured per indicated HP. 

 was 11 \ pounds, and as the same results exactly had been 

 obtained both at Odessa and at Leeds, it could be seen that 

 there was nothing out of the common in this for that 

 particular type of pump. The results at Marrickville had 

 not been so good because the engine there is a compound 

 type, and had to be run at a lower speed being too large 

 for its work ; when the engines were run at full speed there 

 was not sufficient work and the motion was intermittent. It 

 was not until Mr. Furniss hit upon the idea of throttling 

 the delivery pipe that the difficulty thus caused was over- 

 come. He (Mr. Price), believed that there was a certain 

 amount of storage under the Hathorn-Davey system. The 

 discs to which the connecting rods and the plunger were 

 attached must, he thought, store up a certain amount of 

 energy derived from the difference in the motions and 

 speeds. This energy was, he thought, partly instrumental 

 in producing the high rate of expansion observable in 

 Hathorn-Davey pumps as compared with Worthingtons, 

 where there is air storage. When dealing with air expand- 

 ing or contracting there must be a certain amount of loss 



4— Sept, 18, 1907. 



