The water of the lake is perfectly fresh when full, but brackish when low; and that coming down the Tamunak'le we found to be so clear, cold, and soft, the higher we ascended, that the idea of melting snow was suggested to our minds. We found this region, with regard to that from which we had come, to be clearly a hollow, the lowest point being Lake Kumadau; the point of the ebullition of water, as shown by one of Newman's barometric thermometers, was only between 207–½ Deg. and 206 Deg., giving an elevation of not much more than two thousand feet above the level of the sea. We had descended above two thousand feet in coming to it from Kolobeng. It is the southern and lowest part of the great river system beyond, in which large tracts of country are inundated annually by tropical rains, hereafter to be described. A little of that water, which in the countries farther north produces inundation, comes as far south as 20d 20', the latitude of the upper end of the lake, and instead of flooding the country, falls into the lake as into a reservoir. It begins to flow down the Embarrah, which divides into the rivers Tzo and Teoughe. The Tzo divides into the Tamunak'le and Mababe; the Tamunak'le discharges itself into the Zouga, and the Teoughe into the lake. The flow begins either in March or April, and the descending waters find the channels of all these rivers dried out, except in certain pools in their beds, which have long dry spaces between them. The lake itself is very low. The Zouga is but a prolongation of the Tamunak'le, and an arm of the lake reaches up to the point where the one ends and the other begins. The last is narrow and shallow, while the Zouga is broad and deep. The narrow arm of the lake, which on the map looks like a continuation of the Zouga, has never been observed to flow either way. It is as stagnant as the lake itself.
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.
On the day after our arrival at the lake, I applied to Lechulatebe for guides to Sebituane. As he was much afraid of that chief, he objected, fearing lest other white men should go thither also, and give Sebituane guns; whereas, if the traders came to him alone, the possession of fire-arms would give him such a superiority that Sebituane would be afraid of him. It was in vain to explain that I would inculcate peace between them—that Sebituane had been a father to him and Sechele, and was as anxious to see me as he, Lechulatebe, had been. He offered to give me as much ivory as I needed without going to that chief; but when I refused to take any, he unwillingly consented to give me guides. Next day, however, when Oswell and I were prepared to start, with the horses only, we received a senseless refusal; and like Sekomi, who had thrown obstacles in our way, he sent men to the Bayeiye with orders to refuse us a passage across the river. Trying hard to form a raft at a narrow part, I worked many hours in the water; but the dry wood was so worm-eaten it would not bear the weight of a single person. I was not then aware of the number of alligators which exist in the Zouga, and never think of my labor in the water without feeling thankful that I escaped their jaws. The season was now far advanced; and as Mr. Oswell, with his wonted generous feelings, volunteered, on the spot, to go down to the Cape and bring up a boat, we resolved to make our way south again.
Coming down the Zouga, we had now time to look at its banks. These are very beautiful, resembling closely many parts of the River Clyde above Glasgow. The formation is soft calcareous tufa, such as forms the bottom of all this basin. The banks are perpendicular on the side to which the water swings, and sloping and grassy on the other. The slopes are selected for the pitfalls designed by the Bayeiye to entrap the animals as they come to drink. These are about seven or eight feet deep, three or four feet wide at the mouth, and gradually decrease till they are only about a foot wide at the bottom. The mouth is an oblong square (the only square thing made by the Bechuanas, for every thing else is round), and the long diameter at the surface is about equal to the depth. The decreasing width toward the bottom is intended to make the animal wedge himself more firmly in by his weight and struggles. The pitfalls are usually in pairs, with a wall a foot thick left uncut between the ends of each, so that if the beast, when it feels its fore legs descending, should try to save itself from going in altogether by striding the hind legs, he would spring forward and leap into the second with a force which insures the fall of his whole body into the trap. They are covered with great care. All the excavated earth is removed to a distance, so as not to excite suspicion in the minds of the animals. Reeds and grass are laid across the top; above this the sand is thrown, and watered so as to appear exactly like the rest of the spot. Some of our party plumped into these pitfalls more than once, even when in search of them, in order to open them to prevent the loss of our cattle. If an ox sees a hole, he carefully avoids it; and old elephants have been known to precede the herd and whisk off the coverings of the pitfalls on