At Kolobeng, Livingstone first heard of Lake Ngami, north of the Kalihari Desert. He resolved to visit it, and started in May 1849, in company with his wife and children, several English travellers and a large party of Bechuana attendants. They rather skirted than crossed the desert, yet they found it to consist of vast salt plains, which gave a constant mirage as if the whole were water. Though destitute of water, there are tufts of dry salt-encrusted grass here and there, which relieve it of an appearance of barrenness, but which crumble at the touch. In July they struck the river Cubango, or Zonga, flowing eastward and, as far as known, losing itself in a great central salt-lake, or Dead Sea. They were told that the Zonga came out of Lake Ngami, further west. Ascending the river sixty miles they struck the lake, and were the first Europeans to behold this fine sheet of water. The great tribe about and beyond the lake is the Makololo, whose chief is Sebituane, a generous hearted and truly noble character. They could not see him on this trip. So they returned, making easy journeys down the Zonga, admiring its beautiful banks, which abounded in large game, especially elephants. The next year (1850), Livingstone and his family started again for Lake Ngami, accompanied by the good chief Sechele, who took along a wagon, drawn by oxen. While this means of locomotion gave comfort to the family, it involved much labor in clearing roads, and the animals suffered sadly from attacks by the tsetse fly, whose sting is poisonous. But the lake was reached in safety. The season proved sickly, and a return journey became compulsory, without seeing Sebituane. But the chief had heard of Livingstone’s attempts to visit his court, and he sent presents, and invitations to another visit. He set out on a third journey, and this time directly across the desert, where they suffered much for want of water. [Illustration: CUTTING A ROAD.] This time they found the chief. His headquarters were on an island in the river, below the lake. He received the party with the greatest courtesy, and appeared to be the best mannered and frankest chief Livingstone ever met. He was about forty-five years old, tall and wiry, of coffee-and-milk complexion, slightly bald, of undoubted bravery, always leading his men in battle, and by far the most powerful warrior beyond Cape Colony. He had reduced tribe after tribe, till his dominions extended far into the desert on the south of the Zonga, embraced both sides of that stream, and ran northward to, and beyond, the great Zambesi River. Chief Sebituane died while Livingstone was visiting him, and was succeeded by his daughter Ma-Mochisane. She extended the privileges of the country to the travellers, and Livingstone went north to Sesheke to see her. Here in June, 1851, he discovered the great Zambesi in the centre of the continent of Africa where it was not previously known to exist——all former maps being incorrect.