241 



sluggish stream until it is many feet above the natural channel. 

 Then a part of it is turned into the uppermost terraces of the 

 sawah. These are filled to the proper level, and overflow into 

 the next one below. If the terrace is small and the stream of water 

 in proportion, it may spill out over the wall, but usually a split 

 bamboo serves as the conduit. In this way the water in each 

 terrace does not become stagnant, but is used in turn for other 

 terraces, until it finally reaches the lowest and empties back 

 into the river channel. Nor does its usefulness cease here, for 

 the same stream may be diverted many times at successively 



Fig. 26. The mountain garden at Tjibodas, Java. 



lower levels. One can understand why the water of the lowland 

 rivers is so muddy, when it has passed through some hundreds of 

 rice-fields on its way down from the hills. 



The magnitude of some of the irrigation systems is surprising. 

 In Buitenzorg a concrete dam diverts the entire current of the 

 Tji Sadane into an irrigation canal, so that the river bed below is 

 merely a mass of boulders with a few small pools of water. The 

 canal, a hundred feet wide, has been excavated in the hills to a 

 depth of at least fifty feet. In the rural districts one is seldom 

 out of sight or sound of some little canal, running either to or 

 from the sawahs. 



The Preanger plateau, lying to the southeast of Buitenzorg, 



