126 CHAPTER VIII 



practice ; in addition, the burning of the vegetable matter places in the soil 

 a large amount of readily available mineral plant food. 



After the land has been cleared in those countries which employ land 

 carriage, roads wide enough for carts to pass are made through the new 

 sections, and the area divided up into convenient fields ; the land is prepared 

 for cultivation by ploughing, either by manual, animal or steam power. 

 When hand labour is employed, the soil is merely turned over by forks or 

 shovels ; in other cases the whole area is ploughed, cross-ploughed and horse- 

 hoed, and the soil properly broken up and aerated. 



British Guiana. In British Guiana and the Straits Settlements, which 

 are flat alluvial countries, a somewhat more complicated procedure is 

 necessary. The area of the new plantation being decided, three dams formed 

 by the excavation of three trenches are thrown up ; these dams are known 

 as the navigation or middle walk, sideline or drainage, and back dams ; and 

 they enclose the piece of land which is to be put into cultivation. More 

 frequently, however, a double section is formed with two sideline dams and a 



FIG. 39 



back dam- as empoldering dams, a navigation dam running in the centre of 

 the two half-sections, and serving equally for both. In Figs. 40 and 41 are 

 given plans of the arrangements of field customary in British Guiana ; a is 

 the navigation dam formed by the excavation of the navigation trench b ; 

 the navigation trench continues up to the factory, and is used for the transport 

 of cane and produce, and also to supply water for irrigation and other purposes. 

 This canal is connected with a river, creek or lake ; or, where this is impossible, 

 a large canal capable of supplying a batch of estates carries water from 

 a river. Many estates have pumping stations situated on a river, so that 

 they are nearly independent of drought ; on other estates a drought may 

 cause the level of water in the river or creek to fall so much that it is necessary 

 to take sea water into the trenches. At e are shown cross canals communicat- 

 ing with the navigation trench, and terminating about 20 to 25 feet from the 

 sideline or drainage canal c ; the cross canals are used for the purpose of 

 bringing the punts or barges used for transport within access of the canes ; 

 the main drainage canal runs out to the sea or river. Drainage is either 

 forced or natural , in the former case centrifugal or sluice wheel pumps are 

 employed, the first-named being by far the most economical ; in the latter 



