EURAL ENGINEERING. 589 



tion of the first edition (E. S. R., 14, p. 926). The author states that it "em- 

 bodies the essential features of drainage engineering in this country at the 

 present time, with the latest developments along each line, and is adapted to 

 the use of the professional engineer and the student." 



The chapter headings of the book are as follows: Development of land drain- 

 age, the drainage engineer, engineering technique, drainage and how accom- 

 plished, the preliminary survey, underdrains and their location, flow in under- 

 drains, the run-ofi: from uudcnlrained areas, size of tile-drains, selection of 

 drain-tile, construction of tile-drains, flow in open channels, the run-off from 

 large areas, location and construction of open ditches, problems in open-ditch 

 work, drainage districts, levee drainage .systems, reclamation of tidal lands, 

 drainage of irrigated lands, drainage of peat and muck lands, control of hill 

 waters, drainage of home surroundings, and estimates and accounts. A large 

 amount of available data is summarized, including formulas and tabular data 

 for use in various phases of the work. 



Land drainage by means of pumps, S. M. Woodward ( U. S. Dept. Agr., 

 Office Expt. Stas. Bui. 2'i3, pp. Jik, pl^- o. figs. 3). — This bulletin discusses the 

 conditions under which land drainage by means of pumps is feasible, cites 

 successful examples in Europe and this country, and describes in detail opera- 

 tions in the Upper Mississippi Valley. 



" The reclamation for agricultural purposes of river bottom lands lying so 

 low that they are subject to serious injury by overflow has been proved by 

 experience in Europe and in this country to be feasible and profitable when 

 carried out by means of a system of protective levees supplemented by interior 

 drainage ditches and a pumping plant to remove excessive precipitation which 

 may fall within the district. 



" Numerous tracts in units of from 5,000 to 20,000 acres have been thus 

 reclaimed along the Illinois River and on both sides of the Mississippi in the 

 States of Illinois, Iowa, and Missouri. In some districts the cost of the gen- 

 eral drainage improvements, including levees, ditches, and pumping plant, has 

 been as high as $30 per acre. This method of reclamation may be expected 

 to be extended constantly to new localities as agricultural land becomes more 

 valuable. 



" The design and construction of the levees, ditches, and pumping plant 

 require a considerable degree of engineering ability. . . . The levees must 

 originally be made of such height and thickness as to afford ample strength 

 and they must also be given careful subsequent attention to secure proper 

 maintenance. The internal drainage ditches should be deep enough to keep 

 the ground water level at least 3 ft. below the surface and their capacity should 

 be sufficient to dischax'ge heavy rains freely to the pumping station. Streams 

 entering the district from higher ground should be diverted around the levees 

 whei'e such a plan is feasible. 



" The pumping plant should have a capacity sufficient to remove as a mini- 

 mum amount in 24 hours a quantity of water sufficient to cover the entire 

 district to a depth of one-fourth inch. The capacitj' should be greater in 

 situations of heavy rainfall and where the run-off of rolling land is received in 

 the district. 



"The pumping machinery should be so arranged as to reduce to a minimum 

 the work of disposing of the surplus water, and it should be chosen with 

 especial regard to economy and efficiency in operation. Where large fluctua- 

 tions in the river level are to be expected, the machinery must be sufliciently 

 large to operate at the maximum head, and at the same time must be as effi- 

 cient as nracticable for more moderate heads. 



