94 The Drainage of Fens and Low Lands, 



the lift increases the pump adjusts itself to the altered circum- 

 stances by sending out a less quantity, gradually regaining its 

 original discharge as the tide falls. Further, when permanent 

 settlement of the land occurs, the cost of adapting a pump is 

 trifling ; all that is necessary being the lengthening of the inlet 

 pipe. Where proper precautions are taken no practical diffi- 

 culty has been found to arise from weeds and other substances 

 which find their way into the pump well. Pumps have now 

 been running for the last thirty-five years, and performed their 

 work efficiently and without trouble. At the Lade Bank 

 station a manure fork is shown which, having been accidentally 

 dropped into the feeder on the inner side of the grating, safely 

 passed through the pump and came out without stopping the 

 machinery or receiving any damage itself. At the pump- 

 ing station, at Codigoro, North Italy, the body of a lad passed 

 through one of the pumps. The boy had been missed fi-om 

 his home, and it was ascertained that he was last seen in the 

 Valli near the main canal which leads to the suction wells of 

 pumps. Some days afterwards, when one of the engineers had 

 taken off the man-hole cover of condenser belonging to one 

 of the pumps, he discovered the missing body, which had passed 

 through the pump, but its further progress was impeded by the 

 smallness of the condenser tubes. To prevent such accidents 

 the approach to the pump should always be well protected by 

 gratings placed across the entrance to the raceway. 



There are two types of centrifugal pumps — the one similar 

 to the Appold pump shown in the 1851 Exhibition having a 

 horizontal spindle, and almost invariably fixed above the level 

 of the water ; the other of the turbine form, having a vertical 

 spindle, the fan and case being submerged. All the larger 

 stations in England have been fitted with the turbine form, 

 but in Holland and Italy the pump with horizontal spindle has 

 been most generally used. Of the three largest makers of 

 drainage pumps in this country, Messrs. Easton and Anderson 

 have adopted the turbine form for all large works, whereas 



