The next important fact to be observed is that a larger river than any of them, called the Luapula, runs out of the lake into Lake Moero. Out of the northern end of the Lake Moero again another large river, the Lualaba, runs thundering forth through a vast chasm, and then, expanding into a calm stream of great width, winds its way north and west till it enters a third large lake, the Kamolondo. The doctor gave it the additional name of Webb's River. In some places he found it to be three miles broad. He perseveringly followed it down its course, and found it again making its exit from Lake Kamolondo, till it was joined by other large rivers, some coming from the south and others from the east, till he reached the village of Nyangwe, in latitude 4 degrees south. Here, having exhausted the means of purchasing fresh provisions, and his followers refusing to proceed further, he was compelled to bring his journey northward to a termination. This was not till the year 1871. He, however, heard of another enormous lake to the northward, into which the Lualaba empties itself, bounded by a range to the westward called the Balegga mountains. From the information he received, he believed that this last-mentioned lake is connected by a series of small lakes, or by a somewhat sluggish stream, with the Albert Nyanza, the waters of which undoubtedly flow into the Nile. Of course it is possible that the waters which flow out of this large unknown lake, instead of running to the north-east into the Albert Nyanza, may have a westerly or north-westerly course, in which case, instead of making their way into the Nile, they may be feeders of the Congo river. To the south-west of Lake Kamolondo the doctor discovered another large lake, to which he gave the name of Lake Lincoln, after the President of the United States, the liberator of their negro population. Another large river, the Lomame, flowing from the southward, enters this lake, and, passing out again at its northern end, joins the Luaba, which after this takes an almost, northerly course. These discoveries occupied Dr Livingstone three years. After his discovery of Lake Moero, while residing with Kazembe, he unfortunately became acquainted with a half-caste Moor, named Mahommed Ben Sali, who had been detained as a prisoner by the king. The doctor obtained his release, and allowed the Arab to accompany him. The villainous old fellow, in return, did his utmost to ruin Dr Livingstone, by inducing his attendants to desert him, and even Susi and Chumah for a time were won over, though they ultimately returned to the doctor.