204 IRRIGATION FARMING. 



which can be opened or closed to regulate the hight of 

 the water within them. The rising of the Nile begins 

 in June, and during the summer much of Egypt is one 

 vast lake. It remains so through September, and sub- 

 sides toward the latter part of Ocflober. It is at this 

 time that the water is condu(5led into this vast network 

 of canals, and is carefully carried over the cultivable 

 lands. 



In Spain the system for irrigation of meadow lands 

 most commonly applied in the northern provinces is by 

 inclined channels or the system of spiked channels. 

 The distribution channels are devised nearly in the 

 sense of the greatest slopeness of the grounds. The 

 irrigation channels connedl with them and spread out 

 from right to left. A rapid sedlional change takes 

 place in the distribution channels at the point where 

 they separate into branches with the irrigating chan- 

 nels, which by having a gradually narrowing se(ftion 

 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 coUedling channels, 

 called azarbes, dug on the natural lines of jun(5lion 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 colledling channels are changed into 

 new feeding channels for the supply of other lands situ- 

 ated farther 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 



