80 Tj? A XS ACTIONS OF THE AmEUICAX INSTITUTE. 



duties, and a lack of facilities, it would be impossible to liave such 

 test. Upon inquiry -we found that Hardick did not claim that his 

 pump of to-day is essentially different in construction from the one 

 tested in 1867, and that of Messrs. Knowles & Sibley differed only in 

 respect to an improvement whereby the pump valves could be reached 

 in much less time. This then formed a basis to work upon in respect 

 to these two pumps, and with the test of the judges at the 1SG7 exhi- 

 bition (reported on pages 87-91, Transactions of the American Insti- 

 tute, 1867), and the two pumps at the present exhibition before us, 

 we must decide in" favor of the Knowles pump, as we shall presently 

 show. But this test does not reach the Blake pump, we. therefore 

 decided to require of each of the three exhibitors a written statement of 

 the superior qualities and points of excellence claimed for his pump, 

 permitting comparisons to be drawn. Such statements were, in due 

 time, furnished us, and to them we shall hereafter allude. 



"We will now consider the report of the judges at the exhibition of 

 1867. We iiud that the judges tested the pumps on Jive points : 1st. 

 The iirst trial was to determine the relative economy of the pumps. 

 On this trial tlie Knowles pump fell behind the Niagara, but this is 

 easily and satisfactorily accounted for by the fact that the steam 

 piston of the Knowles pump leaked badly ; was " very leaky," as the 

 ju'dges expressed it. By examining carefully the construction of the 

 piston, we find that the fault must have been due to accident, as the 

 means provided by which the packing may be set out and kept tight 

 is efficient in all respects. It was a fault in a particular pump, not 

 incident to like pumps of the same makers ; and the exhilutor of the 

 Knowles and Sibley pump at the present exhibition explains this 

 fully by saying that they had no pump made of the size required by 

 the judges, and that they put the one wliich was tested together 

 hastily. He says : " Our steam piston was left very loose, and, conse- 

 quently, very leaky, simply through a misunderstanding, we supposing 

 it had been properly adjusted at the factory, and the foreman at the 

 works intending to have it adjusted here." AVe believe, therefore, 

 that under ordinary circumstances, tlie two pumps must be considered 

 equal in respect to their pistons, and as the test showed that the 

 valves of the Knowles pump were tighter than those of the Niagara, 

 due doubtless to the fact that the Knowles pump closes the exhaust 

 port of its auxiliary cylinder at every stroke, we must decide that in 

 daily practice the Knowles pump is superior, certainly equal, to the 

 Niagara pump in economy of steam. 



