METHODS OF AIM I. VI. N<; WATEK. 151 



branches with the irrigating channels, which by having 

 a gradually narrowing section from their parting point 

 down to the end, pour out the water by getting inundated. 



Another contrivance is also combined with this dis- 

 tributive system, which consists in collecting channels, 

 called azarbes, dug on the natural lines of junction on 

 the meadow ground, terminating in an outlet channel. 

 Sometimes when the extent of the meadow is not con- 

 siderable, or when the quantity of water available is but 

 small, the collecting channels are changed into new feed- 

 ing channels for the supply of other lands situated far- 

 tluT down. They level off the ground so that the water 

 can flow over it easily, without leaving standing pools and 

 mud, or washing out the ground and forming gullies. 

 They prepare their lands so that the water will flow over 

 them easily and safely. They also construct their lateral 

 ditches very well, and when they are through with the 

 water the supply is turned off. They never waste it. 

 They have only a few small reservoirs. 



In Australia much of the interior land is irrigated 

 mostly through the medium of billabongs or lagoons 

 that are oftentimes supplied from natural streams during 

 the rainy season. The water is applied to the lands 

 much the same as we apply it. In other countries along 

 seashores a system known as warping is customary. By 

 this mode the tides are received through an embank- 

 ment or dyke and retained until the sediment or warp is 

 deposited. Sub-irrigation is a system that is practiced in 

 all countries, including our own, and as it is of much 

 importance as to detail the writer will treat it in a special 

 chapter later on. 



