104 T^^^ Drainage of Fens anct Low Lands. 



of the instalment being considerably less than that of any 

 other type * 



Messrs. J. and H. Gwynne have erected several of these 

 direct-acting engines and pumps in Holland and France, 

 particulars of some of which are given in Chapter VIIL For 

 the drainage of the Middel Polder in Holland, containing 1600 

 acres, a pair of their engines and pumps were erected in 1878. 

 The space occupied by engines and pumps is only 21 feet 

 by 1 1 feet, and they are each capable of delivering 30 tons 

 a minute to a height of 16 feet. Although these engines 

 make 138 strokes a minute, and, when emptying the lake, 

 worked for three months, night and day, they have run for 

 eight years without anything being required to be done to 

 them except ordinary repairs. At the Legmeer Polder a pair 

 of direct-acting vertical engines and pumps were also erected 

 by the same firm in 1875, of which an illustration is here 

 given, Plate 4. Each engine and pump is capable of lifting 

 75 tons 17*38 feet per minute, and occupies a space 15 feet 

 by 10 feet. These engines make 156 revolutions a minute; 

 yet, notwithstanding this high speed, the author was assured 

 by the superintendent in charge that, beyond an accident to 

 the fan of one of the pumps, owing to a piece of wood having 

 got into the case, no stoppage had taken place, and the 

 repairs had only been slight and of the ordinary character 

 common to all machinery. The satisfactory working of this 

 class of pump was confirmed at other stations in Holland 

 which the author visited. TIiq small space occupied by this 

 class of machinery, and the fact of the pump being placed on 

 the same floor with the engine, is the r^eans of effecting con- 

 siderable saving in foundations. In the case of the pumps at 

 Middel Polder, a road intervenes between the engine-house 

 and the river into which the drainage water is discharged ; 

 the ii'on delivery pipes are carried beneath this road, the 



* * Notes on Pumping Machinery for Drainage Purposes,' by J. and H. 

 Gwynne, 1885. 



