488 IRRIGATION FARMING. 



Miner's Inch — A unit of water measurement. 



Module — A French device for measuring water. 



Mudsill — The structure upon which rests the fioor of a head- 

 gate. 



Nilometer — A gauge for measuring and recording the rise and 

 fall of streams. 



Overfall — The apron of a weir or dam. 



Penstock — A pipe for supplying water ; a sluice or conduit for 

 controlling the discharge of water. 



Percolation — Filtration of water through the soil. 



Phreatic — Underground, as the sources of wells ; phreatic 

 waters. 



Pipe-Line — A system of pipe or conduit for conveying water. 



Points — Perforated pipes driven into the earth to secure water 

 for pumps. 



Porosity — Porous condition or possessing pores. 



Puddle — To line, as canal banks, with clay to render water- 

 tight ; preparing plants for transplanting. 



Reduction Box — A device for decreasing the flow of a canal. 



Reservoir — A basin for collecting and impounding water ; a 

 storage lake or pond. 



Rill — A small stream or delicate furrow. 



Ripeurian — Pertaining to the banks of a river. 



Riprap — Broken stone arranged in beds for protecting em- 

 bankments. 



Run-Off — Those waters which escape by natural courses on the / ^ \\ 

 earth's surface ; those waters which do not " fly-off. 11,*;'^ ^ '^ ^ 



Sakiyeh — A rude water-wheel used in Egypt. 



Scund Gate — An appliance for diverting sand from a canal. 



Second Foot — A unit of water measure ; the discharge of one 

 cubic foot a second. 



Seepage — Oozing or percolation of water in soil ; also spelled 

 seapage and sipage. 



Sewage — The discharge from sewers ; waste water. 



Shadoof — An Oriental device similar to a well-sweep. 



Sheet-Piling — Thick planking driven as piles ; the sides of 

 coffer-dams. 



Silt — Detritus or floating matter in a ditch ; sediment. 



