602 LIFE OF DAVID LIVINGSTONE, LL.D. 



of the north end of the lake, and that consequently Tanganyika was the main 

 source of the Nile. Others suggested that the outlet was from the eastern 

 side, and that the Ruaha or Lufiji carried the waters of Lake Tanganyika 

 to the Indian Ocean ; while a third school contended that the lake had no 

 outlet. 



Dr. Livingstone added to the knowledge on the subject which we derive 

 from Captain Burton's admirable work. But the health of the great Explorer 

 was completely worn out when he reached the southern extremity of 

 Tanganyika in April, 1867, and little reliance can be placed on his observa- 

 tions, as he says that his head was out of order at the time. He was then 

 suffering from a severe attack of fever, and in November, 1871, he had lost all 

 count of time. In March, 1869, he passed along the west coast of the lake, at 

 a time when he was again suffering from illness ; and during the fourteen 

 hours of March the 7th, making the voyage against a head wind, and most of 

 the time in darkness, he appears to have passed that part of the coast where 

 the outlet actually is. In November, 1871, he made a voyage to the northern 

 end of the lake, and found that the mouth of the Rusizi is formed of three 

 branches about twelve to fifteen yards broad, and six feet deep, with a strong 

 current of two miles an hour. He ascertained that all the rivers round 

 the northern end flowed into the lake, and thus confirmed Burton's original 

 conclusions. Dr. Livingstone himself does not appear to have formed any 

 definite opinion on the subject of Tanganyika hydrography. At Ujiji 

 he observed that a current flowed northwards at the rate of nearly a mile an 

 hour from February to November. Then evaporation is at its strongest, and 

 the water begins to go gently south, until arrested by the flood from the great 

 rains in February ; so that there is a flow and reflow caused by rains and 

 evaporation on the surface of a lake three hundred miles in length. At one 

 time he seems to have thought there was no outlet, for he accounts for the sweet- 

 ness of the water by the existence of this current flowing " through the middle 

 of the lake lengthways." At another time he says that he has not the smallest 

 doubt that the Tanganyika discharges somewhere, though he may not be able 

 to find the outlet. The question was thus left in a complete state of un- 

 certainty, and the larger portion of the lake was unsurveyed and unvisited, 

 when Lieutenant Cameron reached its shores on the 21st February 1874, 

 exactly sixteen years after their discovery by Captain Burton. 



After a careful survey of the southern and unknown portion of the lake, 

 the young Lieutenant proceeded to explore the western side, and at a dis- 

 tance of twenty-five miles to the south of the Kasenge Islands, visited by 

 Speke and Livingstone, he discovered the river which forms the outlet to 

 Lake Tanganyika on the 3d of May, 1874. This outlet, it appears, is called 

 Lukugu, and had actually been passed by Livingstone, though in the night- 

 time, which might account for his having somewhat hastily concluded that 



