FOR AUXILIARY PURPOSES ON BOARD SHIP. 171 



We have analyzed our figures again to meet Mr. Katzenstein's criticism and have plotted 

 same on Plate 89, on the basis of pounds of steam per 1,000 pounds of water, which still 

 shows the advantages on the side of the turbine pump with hot water. 



Referring to the third paragraph of Mr. Katzenstein's discussion, he states that in the 

 sentence on top of page 169, we are not correct inasmuch as a test of the simplex pump 

 was conducted under circumstances that were decidedly unfavorable. We would like to 

 quote from the oflficial report of this test published in the Journal, which reads in part as 

 follows : — 



"From 100 per cent to 133 per cent the centrifugal pump is more efficient. As the 

 values in the last column are based upon a careful regulation of the number of nozzles in use 

 according to the load, the comparison will be less favorable to the centrifugal pump at light 

 loads if such regulation is not carried out. On the other hand, the test of the simplex pump 

 was conducted under the most favorable circumstances as to the condition of working parts 

 of the simplex pump. Reciprocating pumps decrease steadily in efficiency due to wear, while 

 the centrifugal pump will probably change very little in this respect. Further, the centrif- 

 ugal pump being of an experimental type, certain slight mechanical changes will doubtless 

 improve its efficiency." 



We regret that Mr. Katzenstein did not give us some particulars or figures of the test 

 referred to of the Blake pump which gave such good results at Annapolis, as we are sure 

 this would have made a very valuable contribution to the paper. 



We can hardly agree with Mr. Katzenstein in his statement that the water hammer in 

 piping from direct-acting pumps can be eliminated. It is true that under ideal conditions 

 this is possible, but wherever we have a reciprocating motion there is naturally a strong 

 probability of this occurring, whereas with the centrifugal type the very principle of opera- 

 tion eliminates the possibility of this occurring. 



We are very grateful to Mr. Katzenstein for his additional information regarding the 

 installation of turbine-driven pumps on various commercial steamers. 



Mr. Katzenstein (Communicated) : — The report of the test of the 24-inch stroke Blake 

 pump was not published in the Journal for the reason that we did not wish to have our com- 

 petitors learn about the test or the economy obtained thereby. This pump has a new and pat- 

 ented type of cut-ofif valve, and the results shown are very satisfactory. For further infor- 

 mation, I would say, concerning the statement I made of the test run under unfavorable con- 

 ditions, that this applied to the pump with which the authors made comparisons. This was 

 an old Blake 10X7X12 pump which was loaned by us to the Engineering Experiment Sta- 

 tion when they started. It had been lying about the place for several years when they sud- 

 denly decided to make a test. They did not notify us, we had no one present, and the pump 

 was not in especially good adjustment. However, when the 24-inch stroke pump \tas tested, 

 we had a representative present to see that the pump was run under conditions that were the 

 best possible with the facilities available. I will be glad to give the authors any informa- 

 tion that they may desire in connection with this matter. 



The President : — We must extend our thanks to Mr. Herbert, and to his associate, Mr. 

 London, for their care and trouble in the preparation of this paper, and all the useful infor- 

 mation it contains. 



