66 The Drainage of Fens and Low Lands. 



main engine drain, act not only as conveyers of water to 

 the pump, but also as reservoirs to collect the water when the 

 engine is not running, and should therefore be larger than the 

 calculation would warrant if merely founded on their dis- 

 charging capacity. When steam is once up it is bad manage- 

 ment to allow the engines to stand still for the water to 

 gather, because the drains are not of sufficient capacity to 

 keep them supplied. The pumping station should be placed 

 as near the centre of the district as practicable. The main 

 engine drain will then be of shorter length, and the minor 

 drains arranged in a more effectual way as feeders than if the 

 pumping station be fixed at one end of the district ; the drains 

 falling into it from both directions will also require less fall 

 than if they had traversed the whole length. It is un- 

 necessary to refer further to this matter, as the whole subject 

 has been fully dealt with in the chapter on drainage. 



Cost of Pumping Stations. — The cost of erecting a 

 pumping station depends upon so many circumstances peculiar 

 to the locality that no definite figures can be given. Generally 

 the cost may be taken for buildings and machinery at from 

 70/. to 80/. per horse-power of water lifted. Allowing for an 

 annual average rainfall of from 25 inches to 30 inches, i horse- 

 power would drain about 150 acres with a lift of 5 feet, 

 making the cost per acre about los. The main elements to 

 be taken into consideration are the quantity of water to be 

 lifted — depending principally on the rainfall and the area 

 drained, the height the water has to be lifted, and the nature 

 of the foundations required. Frequently a much greater 

 quantity of water has to be lifted than that due to rainfall 

 from the soakage from other districts through badly con- 

 structed banks. If the district is small, the proportionate 

 cost would be greater, but an increase in lift would be less 

 in proportion, as adding little to the cost of buildings and 

 general arrangements. The cost of erecting the Lade Bank 

 engines in Lincolnshire, in 1868, was 17,000/. ; the area of 



