The International Exhibition: Gwynnes Centrifugal Pump, 1862. ... the patented pump of Messrs. Gwynne...is a large and important affair...the cascade produced being a veritable waterfall...This machine consists of a centrifugal pump, driven direct by two horizontal steam-engines of 20-horse power each, so arranged as to draw the water from a tank on the ground floor of the building, and raise it to an elevation of about 24ft. into an upper tank...the water, falling back into the lower one, forms a beautiful cascade 10ft. wide...The pump, when worked with 30lb. steam pressure, discharges about 100 tons of water per minute...four small pumpcases, connected by pipes with the large pump, [are] fitted with copper mouthpieces. These...on a valve being opened, emit streams of water...No correct opinion can be formed of the great efficacy of this pump, except by regarding the four conditions essential to the proper estimate of any hydraulic machine, viz: The power employed, the quantity of water raised, the height to which it is raised, and the time required to raise it. Casual observers, omitting these considerations, and looking only at the size of the discharge-pipe, may be led to form a very incorrect judgment on this important point. From "Illustrated London News", 1862.