162 RENNIK'S DRAINAGE OF PART VII. 



feet above the same point, giving a fall of only an inch 

 and eight tenths per mile at low water of neap tides. 

 From some of the more distant parts of the same Fen, 

 sixteen miles from the outfall, there would only have 

 been a fall of five tenths of an inch per mile at low 

 water. It was clear, therefore, that even the higher 

 levels of the East Fen could not be effectually drained 

 by the outfall at Anton's Gowt or Maud Foster ; and 

 hence arose the necessity for cutting an entirely separate 

 main drain, with an outfall at a point in the Wash out- 

 side the mouth of the river Witham. 1 This east main cut, 

 called the Hobhole Drain, is about eighteen miles long 

 and forty feet wide, diminishing in breadth according to 

 its distance from the outfall ; the bottom being an inclined 

 plane falling four inches in the mile towards the sluice at 

 Hobhole in the Wash. This drain is an immense work, 

 defended by broad and lofty embankments extending 

 inland from its mouth, to prevent the contained waters 

 flooding the surrounding lands. It is protected at its sea 

 outlet by a strong sluice, consisting of three openings of 

 fifteen feet each. When the tide rises, the gates, acting 

 like a valve, are forced back and hermetically closed ; 

 and when it falls, the drainage waters, which have in 

 the mean time accumulated, force open the gates again, 

 and the waters flow away down to the level of low 

 water. A connection was also formed between the main 

 drains emptying themselves at Maud Foster (three miles 

 higher up the Witham) and the Hobhole Drain, the 

 flow being regulated by a gauge ; so that, during heavy 

 floods, not only the low land waters of the East Fen 

 districts were effectually discharged at Hobhole, but also 

 a considerable portion of the drainage of the West and 

 Wildmore Fens. 



An essential part of the scheme was the cutting of the 

 catch water drains, which were carried quite round the 



1 See the Map, in Vol. I., of the " Fens as Drained in 1830 ;" p. 51. 



