Pumping Stations. 



137 



ments with smaller pumps, the ratio which the water horse-power 

 bears to the indicated horse-power. The details of these trials are 

 given in the following table. These short experiments may not give 

 results so strictly accurate as more lengthened trials, but they are 

 consistent in agreeing with those obtained from the smaller pumps, 

 and it is evident that in these machines remarkably high efficiencies 

 were obtained, considering the small horse-power and the low lifts. 

 The difficulty in preventing waste of energy while raising a large 

 volume of water rapidly through a small height is obvious enough, 

 pump and engine friction making a larger fraction of the total power 

 uselessly expended when the lift and water horse-power are small. 

 It is important to observe in these experiments the steady increase 

 of efficiency with increase of lift. 



Trials of the Gallejon Fumps, — Table of discharge and efficiency 

 corresponding to different heights of Hft and to variable speeds. 



Height of Lift in 

 Metres. 



I'OOO I 



(0*900 to I'lOO); 



1*322 I 



(1*300 to 1*350); 



1*540 

 (1*520 to 1*560)' 



I '800 

 (1*760 to 1*840)- 



2*000 



Revolutions. 



65*4 

 71*5 



86*5 



101*3 



90*6 

 107*7 

 117*5 



93*0 

 103*0 



li6*o 



94*0 

 106 '5 



120*0 



107*0 

 119*0 



Di«;charge in 



Litres per 



Second. 



453 



716 



1280 



1634 



I24I 

 1748 

 1990 



1070 

 146 1 



1884 



955 

 1448 

 1892 



1314 

 1738 



Efficiency between work 



shown on pistons and 



eflfective work in water 



raised. 



0*325 

 0*428 

 0*446 

 0.504 



0*603 

 0-568 

 0*511 



0*622 

 0*618 

 0*581 



0*658 



0*797 

 0*634 



0*718 

 0*678 



FoNDi, Southern Italy. — In the year 1882 the Provincial Board 

 of Public Works of Casserta entered into a contract with Messrs. 

 Guppy and Co., of Naples, for two complete sets of steam engines 

 with centrifugal pumps, which were guaranteed to raise 20,500 

 gallons (equal to 91 "51 tons) of water per minute to a height of 7 feet 

 8 inches, for the purpose of draining part of the marshes near Fondi, 

 for reclaiming the land for cultivation, and at the same time rendering 

 the neighbourhood more healthy. This large extent of constantly 



