The Teoughe and Tamunak'le, being essentially the same river, and receiving their supplies from the same source (the Embarrah or Varra), can never outrun each other. If either could, or if the Teoughe could fill the lake--a thing which has never happened in modern times--then this little arm would prove a convenient escapement to prevent inundation. If the lake ever becomes lower than the bed of the Zouga, a little of the water of the Tamunak'le might flow into it instead of down the Zouga; we should then have the phenomenon of a river flowing two ways; but this has never been observed to take place here, and it is doubtful if it ever can occur in this locality. The Zouga is broad and deep when it leaves the Tamunak'le, but becomes gradually narrower as you descend about two hundred miles; there it flows into Kumadau, a small lake about three or four miles broad and twelve long. The water, which higher up begins to flow in April, does not make much progress in filling this lake till the end of June. In September the rivers cease to flow. When the supply has been more than usually abundant, a little water flows beyond Kumadau, in the bed first seen by us on the 4th of July; if the quantity were larger, it might go further in the dry rocky bed of the Zouga, since seen still further to the east. The water supply of this part of the river system, as will be more fully explained further on, takes place in channels prepared for a much more copious flow. It resembles a deserted Eastern garden, where all the embankments and canals for irrigation can be traced, but where, the main dam and sluices having been allowed to get out of repair, only a small portion can be laid under water. In the case of the Zouga the channel is perfect, but water enough to fill the whole channel never comes down; and before it finds its way much beyond Kumadau, the upper supply ceases to run and the rest becomes evaporated. The higher parts of its bed even are much broader and more capacious than the lower toward Kumadau. The water is not absorbed so much as lost in filling up an empty channel, from which it is to be removed by the air and sun. There is, I am convinced, no such thing in the country as a river running into sand and becoming lost. The phenomenon, so convenient for geographers, haunted my fancy for years; but I have failed in discovering any thing except a most insignificant approach to it.
My chief object in coming to the lake was to visit Sebituane, the great chief of the Makololo, who was reported to live some two hundred miles beyond. We had now come to a half-tribe of the Bamangwato, called Batauana. Their chief was a young man named Lechulatebe. Sebituane had conquered his father Moremi, and Lechulatebe received part of his education while a captive among the Bayeiye. His uncle, a sensible man, ransomed him; and, having collected a number of families together, abdicated the chieftainship in favor of his nephew. As Lechulatebe had just come into power, he imagined that the proper way of showing his abilities was to act directly contrary to every thing that his uncle advised. When we came, the uncle recommended him to treat us handsomely, therefore the hopeful youth presented us with a goat only. It ought to have been an ox. So I proposed to my companions to loose the animal and let him go, as a hint to his master. They, however, did not wish to insult him. I, being more of a native, and familiar with their customs, knew that this shabby present was an insult to us. We wished to purchase some goats or oxen; Lechulatebe offered us elephants' tusks. "No, we can not eat these; we want something to fill our stomachs." "Neither can I; but I hear you white men are all very fond of these bones, so I offer them; I want to put the goats into my own stomach." A trader, who accompanied us, was then purchasing ivory at the rate of ten good large tusks for a musket worth thirteen shillings. They were called "bones"; and I myself saw eight instances in which the tusks had been left to rot with the other bones where the elephant fell. The Batauana never had a chance of a market before; but, in less than two years after our discovery, not a man of them could be found who was not keenly alive to the great value of the article.