But when Stanley floated down the Congo in 1877, he saw great rivers entering it from the north. It occurred to him, and to the explorers who followed him, that one of them was probably the lower course of Schweinfurth's Welle. For years this and that river was talked about as the possible outlet of the Welle.
Stanley thought it was very likely identical with the Aruwimi, and he published his hypothesis in his book The Congo in 1885. He had never seen the mighty flood that the Mobangi pours into the Congo, hundreds of miles below the Aruwimi confluence.
Nobody knew, until after Stanley's book was published, that one of the greatest and most modest of explorers, the late Dr. Wilhelm Junker, had already traced the Welle—or the Makua, as he called it—for hundreds of miles, to a point far west of the Aruwimi, proving that it could not possibly be that river. For nearly seven years (1879-86) this man of science lived alone near the upper waters of the mysterious river, studying Nature and Nature's children, eating the food his black friends sold him, including fried ants and other relishes and dainties not known in our cuisine, and wandering through the land with only a cane in his hand, and a few black servants to carry his baggage. At the frontier of a new district he always pitched his camp, sent his presents forward to the chief, made his peaceful purpose known, and asked permission to go on. In all these years he never fired a hostile shot; and late in 1882 he set out down the river to find if it really flowed to Lake Tchad.
But Junker's heart was heavy within him. How could he map the unknown region he was entering? His scientific equipment was worthless. Some instruments had been broken during mouths of incessant travel. Others had been ruined by the humid climate. He had absolutely nothing except a compass to aid in determining his positions. Destitute of scientific outfit he determined to make up for it, as far as he could, by scrupulous care, and the most minute exactitude he could attain in his route survey.
JUNKER TRUDGED ALONG, COMPASS IN HAND.
So Dr. Junker trudged along through the grass, that was often higher than his head, compass in hand, counting every step. Every fifteen minutes he stopped and jotted down in his note-book the distance and the mean direction travelled in the preceding quarter of an hour. He noted all the little streams, the names of villages, the hill features, and so on; and at night he drew on his route map, with the greatest care, the journey of the day, and all the data that may be recorded on a map. Geographers still examine with great interest these neat and methodical map sheets. But they did not know, till years after Junker had returned home, that he had achieved, as we shall see, one of the most remarkable geographical feats on record.
Junker kept up this trying routine through all the weeks of his long journey. Compelled at last to turn back, when nearly four hundred miles on his way, by news that the Mahdists might destroy all the collections he had left behind, he computed the latitude and longitude of his farthest point. All the facts for this computation were his note-book records and the known position of his starting-point. When he returned home, he and Dr. Hassenstein, a famous German cartographer, sat down and laboriously dug through Dr. Junker's records again. The result was almost the same that Junker himself had reached.
The time came when Lieutenant Le Marinel, ascending the great river from the Congo, reached Dr. Junker's farthest. With his instruments he fixed the geographical position of this point, and found that it was practically just where Junker and Hassenstein said it was. Junker's determination, made without instruments, at the end of a long journey, was not more than a mile or two out of the way.