Irrigation in Asia 83 



vation, supporting 41,000,000 people, is under irrigation ; that is 

 .to say, water is artificially applied to not less than 8,000,000 acres 

 of land in Japan. 



On the island of Lew Chew, belonging to Japan, the greatest 

 care is exercised to utilize the water of all the short streams, 

 wherever they are found. On the slopes and in the narrow val- 

 leys, the lands are carefully leveled by terracing, to avoid washing 

 and to cause the water to spread evenly over the surface of the 

 ground, and thus become most effective. On the margins of the 

 terraces are slight ridges, which are given permanency of form 

 by being covered with grass ; these are boundaries and foot- ways, 

 as well as barriers against land washing. It is said that dams 

 are not used upon the streams, but in times of h]gh water the 

 terracing has been such that the water can be at once spread out 

 over the cultivated areas, and gently let down to the lower levels 

 and back into the main channels, after having done its work of 

 saturating and fertilizing the fields. In order that nothing shall 

 be lost by way of washing, there is a lower waterway around the 

 margin of the terraced areas, which conducts the water to one 

 corner, where it passes to the next terrace below, but first flowing 

 through a sort of settling basin partly filled with vines or rubbish, 

 whose purpose it is to collect the silt, to be used in compost heaps 

 for manure. At the lowermost level, before the water finally 

 enters the stream, there is a larger settling basin, through which 

 the water must pass and drop whatever of value it may still 

 be carrying where it may be recovered and used. 



In writing of irrigation in Siam, Consul -General Jacob T. 

 Child states that about one-half of that country is under cultiva- 

 tion, and of this four -fifths are irrigated, much of it for rice. 

 The fields are supplied with water from canals, which branch out 

 from the rivers in all directions, and the main lines are con- 

 structed by the general government, but those supplying the 

 individual fields directly are made by the individual land 

 owners. Where the land is government property, there is an 

 annual rental of about 28 cents per ri, or 84 cents per acre, 

 including the use of the water. 



Irrigation in other parts of Asia at the present time, as is 



