He traces that voluminous river until it enters a shallow lake called Bangweolo, which spreads out on either hand beyond sight, like a sea. He attempts to navigate it; his intention is frustrated by a calamity--the last of his medicines are lost, his instruments are damaged. He determines to go by land, reaches Cazembe, and by the natives he is told of other lakes and rivers without end, all trending northward. He directs his steps north and west to gather the clues to the riverine labyrinth, until he is, perforce, halted by utter exhaustion of his means. He meets an Arab, begs a loan for mere subsistence; and, on that account, must needs march whither the Arab goes. Hearing of a caravan bound coastward, he writes a letter to Zanzibar in 1867, and directs that goods should be sent to him at Ujiji; and, bidding his soul possess itself with patience, he wanders with the Arab merchant for a whole year, and, in 1869, arrives at Ujiji. There is nothing there for him; but a draft on Zanzibar suffices to purchase, at an extortionate charge, a few bags of beads and a few bales of cloth, with which he proposes to march due west to strike that great river discovered two years before so far south. This is loyalty to a friend with a vengeance! The friend to whom he had given his promise, had he but known to what desperate straits the old man was reduced, would long ago have absolved him. Livingstone was now in his fifty-seventh year, toothless, ill-clad, a constant victim to disease, meagre and gaunt from famine: but Livingstone’s word was not a thing to be obliterated by forgetfulness--he had made it his creed, and resolved to be true to it. Well, this insatiable zeal for his word demands that he proceed due west, to find this river. He travels until within a hundred miles of it, when he is stricken down by African ulcers of a peculiarly virulent type, which confine him to his bed for months. During this forced rest, his few followers become utterly demoralised; they refuse to stay with a man who seems bent on self-destruction, and so blind, they say, that he will not see he is marching to his doom. The ninth month brings relief--his body is cured, a small re-enforcement of men appear before him, in answer to the letter he had sent in 1867.