84 Irrigation and Drainage 



the case both in Japan and China, is carried on in a small way 

 largely by individual effort, but is widely and irregularly scattered, 

 so that it is difficult to form any exact or even adequate estimate 

 of the extent of such irrigation ; and the same statement is also 

 true of British India outside of the organized enterprises of 

 English capital. Indeed, it must be said that all through Asia 

 Minor and Central Asia isolated and individual irrigation plants 

 are to be found, which in the aggregate would sum up a grand 

 total. Irrigation is carried on in this individual way in Corea, in 

 Afghanistan, and parts of Russian Central Asia. It is even to be 

 found in Thibet and on the Pamir, "The Roof of the World," 

 12,000 feet above sea level. Nor can it be said that this irriga- 

 tion is carried on only in those places where water is most easily 

 obtainable, for it is sometimes secured under conditions so labo- 

 rious that few Americans would think of undertaking the task. In 

 parts of Armenia, for example, where underground water is 

 abundant, and where the ground is sloping, it is a common prac- 

 tice to dig a line of wells extending down the slope and then, by 

 connecting the bottoms of these wells by a tunnel leading out 

 upon the surface at a lower level, the water becomes available for 

 irrigation, and is collected in reservoirs, to be used as needed. 

 Water is thus collected and brought to the surface of the ground 

 by gravity, even in sections where the uppermost wells must be 

 sunk to depths as great as 80 to 100 feet. The same practice also 

 is said to exist in the mountainous parts of Afghanistan, Cashmere, 

 and other parts of Central Asia, and these underground water 

 channels are often of considerable length, and many miles in 

 the aggregate have been constructed. 



On the continent of Africa, the most extended system is, of 

 course, that found in Egypt, developed along the valley and 

 delta of the Nile. Willcocks tells us, in his "Egyptain Irriga- 

 tion," that the cultivated or irrigated area in this long, narrow 

 valley is 4,955,000 acres, while the total area which is below the 

 level of flood waters, and, therefore, capable of irrigation, is 

 6,400,000 acres. This irrigated area is confined at present to a 

 long and relatively very narrow strip bordering the course of the 

 stream, and the naked desert sands on both sides come up sharp 



