house than from the colour of its waters. The Senku, or chief eastern headstream, is regarded as its true upper course, although exceeded in length by the Vaal. It has its source in an upland valley on the southern slope of the Cathkin, and flows at first in a south-westerly direction between the Maluti and Drakenberg highlands. In this part of its course it rolls down a dark stream, whence its local name of the "Black River." After its junction with the Senkunyané, or Little Senku, it is again swollen by the Malitsunyané, which descends from the western uplands, and which at one point plunges from a vertical height of 600 feet into a tremendous mountain gorge.
After escaping from these romantic Maluti highlands, the Orange mingles its waters with the unite] stream of the Caledon and the Kornet-spruit, which nearly double its volume, and both of which flow from the grassy Potong uplands through broad beds of sparkling mica sands. Below the confluence, the Orange, which from this point flows mainly in a north-westerly and westerly course, is joined by a few streams or rather wadys from the Cape highlands, the chief of
which is the Hartebeest, whose upper course rising in the Sneeuw-bergen, is known as the Zak or Zeku. But all these contributions scarcely suffice to repair the loss caused by evaporation.
The only important affluent of the Middle Orange is the Vaal, or "Gray," one of whose upper branches, the Namagari, has its source, like the Caledon, on the Potong plateau. But its farthest headstream takes its rise on the uplands which skirt the seaboard of the Indian Ocean to the south of Lourenço Marques. Were the question to be decided by the length of their several courses, of all these affluents the Vaal would have to be regarded as the true mainstream. But its valley to a great extent traverses arid plains or dried-up lacustrine beds belonging to a former geological epoch; hence it sends down very little water, usually reaching the confluence in an almost exhausted state. But like the other rivers of this basin it is subject to sudden freshets, several of which occur between the end of November and the middle of April, and while they last the Vaal is transformed to a formidable watercourse. Both the Orange, Caledon, and Vaal may generally be forded; but during the floods they can be crossed
