iv Preface, 



distance from the sea, the cost of deepening and improving 

 the channel of the river, or the length of main drain required 

 to be cut to carry the water to a lower outfall, frequently 

 through high intervening land, makes the cost of drainage by 

 gravitation greater than that by steam-power. 



The greater part of the matter contained in this book, and 

 most of the illustrations, appeared during the year 1887 as a 

 series of articles in The Engineer^ entitled * The Drainage 

 of Fens and Low Lands by Steam Power/ and the Author 

 here acknowledges the kindness of the Editor of that journal 

 in allowing him the use of the engravings. 



The information given has been obtained from various 

 sources — partly from descriptions of drainage works contained 

 in engineering publications, and from well-known works on 

 hydrology. A great portion of the matter is entirely new. 

 The Author's own experience as an engineer living in a fen 

 country, combined with a personal inspection of all the prin- 

 cipal drainage works in England and Holland, has given him 

 the opportunity of collecting together a large number of facts, 

 a record of which he hopes will be of service to those having 

 to design new works, or the superintendence of those already 

 in existence. For the ready assistance of those who have aided 

 him in the matter, the Author here tenders his best thanks. 



In order to facilitate comparison of the different kinds of 

 machinery in use for lifting water, the results are in every case 

 reduced to one common standard in English measures of tons 

 of water lifted to a given height in feet, and of work done in 

 water lifted and discharged, expressed by the term water- 

 horse-power (W.H.P.). 



In the Appendix will be found several useful formulae for 

 making hydraulic calculations. As the works in other coun- 

 tries are almost invariably given in French weights and 

 measures, the equivalents of these in English terms are also 

 given in one of the tables. 



