XLVI. J. F. FURNISS. 



imported pump, but the latter ceased to suck sooner than 

 the others. It had not been explained why this should be. 

 The locally manufactured pump discharged more water 

 with more efficiency, but it required a greater head over the 

 mouth of the suction pipe. That could in his opinion be 

 very easily remedied. If a pipe were parallel (that is, of 

 tiie same girth throughout), the water had to get its velocity 

 suddenly. Water by its composition was opposed to this 

 sudden acquirement of speed. This trouble could be over- 

 come by giving the pipe a bell-shaped mouth. In the 

 abstract it had also been stated that the constructors of 

 centrifugal pumps appeared to have treated the question 

 of end thrust in a lax manner. He understood that the 

 best centrifugal pumps had suction pipes on both sides of 

 the spindle; if on one side only it would mean that there 

 would be a great weight of water pressing on that side. 

 Was the end thrust due to the impact of the running water 

 forcing the pump to one side? More information was 

 wanted about end thrust. 



The figures in connection with economy of steam con- 

 sumption also required carefully looking into. From the 

 diagram the pumps would seem to be very efficient, but 

 the coal bill showed that they were not. This required 

 explanation. Had the wetness of the steam anything to 

 do with it or was it due to condensation in the cylinders? 

 He believed that in the Hathorn Davey pump engine there 

 was a great danger of loss of steam through leakage, 

 especially through working with wet steam. One of the 

 great problems of engineers was to get a tight slide valve. 

 Had any experiments been made to explain the missing 

 steam shown in the diagrams? The diagrams were very 

 good to look at. Missing steam had been attributed to 

 condensation and evaporation in the cylinders, but it could 

 hardly all be due to those causes. 



