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IKKIGATION ON THE OEANGE EIVEE. 

 By F. B. Parkinson, A.E.S.M. 



(Eead March 26, 1902.) "^ 



The economical irrigation of smah areas along the banks of the 

 Orange Eiver by means of modern machinery is a problem that 

 does not appear to have received as much attention as it deserves. 

 A short description of a position and plant v^here this has been 

 successfully accomplished may therefore prove of interest. 



The position of Baviaankrantz is an exceptionally good one for 

 the purpose, being only 20 miles up-stream from Orange Eiver 

 Station, and the road being good, it is easy to get the produce to 

 market. 



The essential geological features are the escarpment of a basalt- 

 capped plateau, along the foot of which the river ran at no very 

 distant period. As the river cut deeper and deeper into the friable 

 shale, which is the principal country rock here, it has retired from 

 the bay-shaped foot of the plateau, leaving behind it a smooth sheet 

 of alluvial deposit, having an average thickness of 15 feet and 

 an area of about 800 acres, almost perfectly level, with a gentle 

 slope towards the present position of the river. The river has now 

 canyoned itself some 60 feet below this alluvial, so that it is on 

 very rare occasions that a flood reaches it to add its inch or so of 

 new silt after the manner of the Nile. 



The walls of the plateau rise quite abruptly to a height of 200 

 feet, and are scored with intermittent watercourses and capped 

 with rugged cliffs of basalt, with their accompanying taluses and 

 screes, and the wastings of these has deposited a fringe of soil 

 around their bases varying from quite a clayey nature to the well- 

 known red earth that results from the weathering of basalt. Thus, 

 then, we have an ideal for agriculture, sheltered on three sides by 

 hills and on the fourth by the dense fringe of trees along the river- 

 banks, and having a more than sufficient depth of a variety of soils 

 suitable to the different crops. At the up-stream end of this land 

 the river issues from a cutting it has made in a ridge of hills that 



