19 



thorough way. The planting distances were 8' X 30', and 

 pipes were put in at every four rows, i. e. at intervals 

 of 32 feet, these draining into other pipes at a lower 

 level. In this way the upper 3 feet of ground were 

 drained. The cost of it was estimated at $ 6$ 8 per 

 acre for laying and about $ 3 for the yearly maintenance 

 (see fig. 7). 



In some cases, on low, clayey grounds, other means 

 besides piping have been employed. Between the Heveas, 

 rows of bananas were planted, not as a catch crop, but 

 with the view of absorbing the subsoil water. Every- 

 where on those estates where such "natural drainage" 

 was employed, the results were extremely satisfactory. 

 The plantation which I saw dealt with in this way made 

 a very favourable impression on me. 



The clay lands which require drainage are not only 

 to be met with in the flat country near the sea-coast, 

 but also on the hills where the clay is forming itself 

 into pockets, something like the Dunes in Europe. In 

 any case quick and well designed drainage is imperative. 



2. SURFACE DRAINS. 



In the hills, surface drains are generally made with 

 another object; not so much to drain off the surplus of 

 subsoil water, as to prevent the constant denudation of 

 the surface soil by storm water. As a rule not much 

 attention is paid to this matter in Java ; on many 

 estates nothing at all is done to prevent it, although 

 Hevea seems to be just such a plant for which the 

 surface soil should be carefully kept together. The side 

 roots spread themselves very extensively in the surface 



