PREFACE, 



The drainage of fens, polders, and low lands, although a 

 matter of great importance, is a subject on which it is difficult 

 to obtain information. There is no complete treatise on the 

 drainage of low land by gravitation or by steam-power to 

 which an engineer called in to advise can refer. Numerous 

 papers describing drainage and reclamation works are to be 

 found in the * Transactions of the Institution of Civil Engi- 

 neers ' and in the engineering journals, yet these are too scat- 

 tered to be of ready service ; and there are many important 

 drainage works of which no record exists. The Author has 

 endeavoured in the following pages to supply this want 



The lands dealt with are such as lie below the level of ordi- 

 nary high water of the sea, and therefore require embanking, 

 and special contrivances for securing proper outfalls for their 

 drainage. These lands may be divided into four classes. 

 First, those that are situated at a sufficiently high level as to 

 be able to discharge their drainage during low water ; these 

 require only protecting from inundation at high water by em- 

 bankments, and the main drains by sluices, which will discharge 

 the contents of the drains at low water, but close against the 

 rising tide. Second, lands at a lower level, which can obtain 

 a discharge by gravitation under ordinary circumstances, but 

 require that the water should be lifted out of the main drain 

 by mechanical power during floods. Third, lands lying 

 beneath low-water level, or so low that mechanical agency is 

 required during that portion of the year when the rainfall 

 exceeds the evaporation. Fourth, land, adjacent to the upper 

 reaches of tidal rivers, the suiface of which is sufficiently high 

 to obtain efficient drainage by gravitation, but owing to the 



