In 1484 Diogo Cam, a Portuguese navigator, first sighted the mouth of the Congo River. Four centuries have since elapsed, and only now have we the definite knowledge of the course of that mighty flood. Seven years after the discovery of the river, an embassy was sent to the capital of the Congo country, known as San Salvador; Roman Catholic missionaries followed, who in time penetrated some 250 miles into the interior. They made, however, San Salvador their head-quarters and cathedral city, but were finally expelled by the Governor of Angola some 130 years ago. They appear to have kept away from the river; what records of their work remain throw no light as to its course. The slave trade flourished in the mouth of the river, but interiorwards the land remained unknown.
In 1816 Captain Tuckey was commissioned by the Admiralty to endeavour to solve the mystery, and was instructed to ascertain whether there was any connection between the Niger and the Congo. This ill-fated expedition penetrated to a distance of 150 miles from the coast. And this was the extent of our knowledge of its lower course until recently.
In 1871 Dr. Livingstone, travelling westward from the Lake Tanganika, discovered a great river flowing northward, called by the natives Lualaba. After three and a half months he returned to the Tanganika, and finally striking south, died at Ilala, on the south of Lake Bangweolo, the upper waters of the Congo-Lualaba, in April, 1873.
Lieut. Cameron, commissioned by the Royal Geographical Society to carry fresh supplies and aid to Dr. Livingstone, met his dead body being conveyed to the coast by his faithful servants. Continuing his journey with the material he hoped to deliver to the Doctor, he crossed the Tanganika, and reached Nyangwe, the point where Dr. Livingstone had first sighted the Lualaba. He would have followed the course of the mysterious river; but was unable to induce his men to attempt the solution of the problem, and striking southwards skirted the lower edge