PUMPING MACHINERY OF THE WATER AND SEWERAGE BOARD. LXI. 



purposes. The reservoirs were filled at night when there 

 was no outflow, and the contents of the reservoirs were 

 then set down as the work done. That was the method 

 adopted by Mr. Smail in his recent trials. The results of 

 these trials showed a duty of 66*68 million foot pounds per 

 thousand pounds of steam for the turbo engines, very good 

 work. These trials were actual facts, he had seen the in 

 himself. Mr. Selfe had been talking of the work necessary 

 to overcome the resistance of the column, in connection 

 with the Marrickville pump. This pump had a belimouth 

 suction. The total head was in this case only 45 feet, 

 measured from the valve boxes to the point of discharge, 

 the wells being 25 feet deep. That was why this particular 

 engine could not produce the same wonderful results as the 

 other two, notwithstanding its many splendid arrangements. 



Referring to the wonderful Spottiswoocle pump that has 

 proved so economical, Mr. Furniss said that the surfaces 

 of the piston and the internal surfaces of the cylinder were 

 perfect planes. There was therefore very little clearance 

 and great economy of steam consumption was thus obtained. 

 He then described how thoroughly the steam was utilised 

 in this engine, which contained the simplest valve gear he 

 had ever seen; they were semi-rotative valves, very similar 

 to those of the Worthington pump, and passed right through 

 chambers in the covers independently of the cylinders 

 altogether. The clearance of this engine also was very 

 small indeed, and there was very little loss. There were 

 no large valve chests to fill with steam because the steam 

 passed direct to cover. There were two valves, one steam 

 and one exhaust, and the valve gear by which they were 

 operated consisted merely of bell cranks on the end of the 

 spindles ; these valves were very easily governed by positive 

 cut off gear. 



(Mr. Selfe here explained that his remarks about the 

 Spottiswood pumps had been made under a misapprehension. 



