20 Transactions of the South African Philosophical Society. 
of mica-schist intersected by veins of dolerite and crystalline lime- 
stone. 
The Tsoachaub River, like most South African rivers, only flows 
in the rainy season, 7.e., during the summer months, but although 
the river-bed is dry for the rest of the year, water may generally be 
found by digging into the sand to a depth of a few feet. The 
vegetation on the banks of the river is fairly luxuriant. Amongst 
the herbage were noticeable grasses of various kinds, saltbush, and 
mesembriaces, whilst amongst the trees and shrubs the most 
prominent were the kameeldoorn, mimosa, and tamarisk. Having 
ascended the mountain on the north side of the river, a height of 
somewhat over 1,000 feet, we proceeded in a north-easterly direction 
towards Omaruru, over a bare plateau on the north-west side of the 
Kau River, which flows in a south-westerly direction and joins the 
Tsoachaub River. The geological features of this plateau are mica- 
schist and limestone, passing over into sandstone, interspersed with 
granite. 
At a place called Aukas, we crossed the Kau River for the first 
time. Here we saw, together with other varieties of acacias, one 
variety known as the Ana-tree, the pods of which are largely used 
as cattle food in very dry seasons. In the limestone which exists. 
here, forming a substratum, as in other parts of the country, water 
is found at a depth of 10 feet and less. Usually where an outcrop 
of this limestone occurs on the surface, shallow wells have been 
sunk into it, and a sufficient supply of water has been obtained. 
After a journey of thirteen days we reached Omaruru, a distance 
of 144 miles from the Tsoachaub mouth, and about 3,600 feet above 
sea-level. This was formerly a mission and trading station; now, in 
addition to this, a detachment of troops is stationed there. The 
mission and trading stations are situated on the north side of the 
Omaruru River, the military camp has been built on the south side. 
Here the efforts of the missionaries have shown what can be done in 
the way of cultivation, with energy and care. In the missionary’s 
garden and other gardens were to be seen vegetables of various 
descriptions in promising condition, together with grape-vines, 
orange-trees, pomegranates, and date-palms. The officer in charge 
of the military station had also laid out a large extent of garden 
ground on the opposite side of the river, upon which much attention 
was being bestowed. After the rainy season, when the river has 
ceased to flow, the river-bed is made use of for the cultivation of 
cereal crops; the results are usually very good, but occasionally an 
unexpected rainfall brings the river down before the crops are 
matured, and the harvest prospects are ruined. The natives in the 
