LOW LIFT PUMPING MACHINERY, LXXIX. 
The reference to Mr. Appold’s pump at the Exhibition of 1851 
as the introduction of that system of raising water, might mislead 
perhaps ; and as he (Mr. Selfe) had a most vivid recollection of 
that portion of the machinery department where those pumps 
were shewn at the Crystal Palace in 1851, he could say that 
Gwynne was equally as well represented there as Appold, but as 
Appold delivered the water from his pump in a broad waterfall 
it attracted more attention from the public. The Appold pump 
itself was out of sight in a wooden casing, but the Gwynne pump 
was very similar to the pumps of the present day. It was here, 
in the trials of these two pumps, that the difference as to the 
merits of radial versus curved vanes first came under his (Mr. 
Selfe’s) notice. 
With regard to the use of centrifugal pumps for high lifts, the 
author shows that it either means large fans or an excessive 
number of revolutions, or conjugate pumps, one delivering into 
the other ; in either case lowering the efficiency to such an extent 
that he does not consider it advisable to use the centrifugal pump 
for greater heights than 40’. Now he (Mr. Selfe) from a cursory 
examination of the conjugate or duplex pump exhibited by the 
author, considered it was so extremely badly designed that he 
was glad to find the author was in no way connected with the 
design. He further considered that the fact that centrifugal 
pumps are not yet used for higher lifts, simply shows that up to 
the present time the requisite inventive talent has not been 
developed to make them efficient, or that the occasion has not 
arisen yet to justify such machines being constructed. Mr. 
Houghton shows that Farcot of Paris has constructed centrifugal 
pumps to give 657 efficiency, and states that up to 30’ the results 
are better than those for reciprocating pumps. If such be so, 
then if thirty-one tanks were fixed, at intervals of 30’ apart, on 
the Eiffel Tower, the bottom one on the ground and the top one 
on the 900’ stage of the’ tower, and thirty centrifugal pumps 
were fixed to lift the water through the intervening stages, is it 
_ hot certain that the work of each pump would be similar, and 
