“Long since,” replied the doctor. “The exploration of the Niger and its tributaries was the object of several expeditions, the principal of which I shall mention: Between 1749 and 1758, Adamson made a reconnoissance of the river, and visited Gorea; from 1785 to 1788, Golberry and Geoffroy travelled across the deserts of Senegambia, and ascended as far as the country of the Moors, who assassinated Saugnier, Brisson, Adam, Riley, Cochelet, and so many other unfortunate men. Then came the illustrious Mungo Park, the friend of Sir Walter Scott, and, like him, a Scotchman by birth. Sent out in 1795 by the African Society of London, he got as far as Bambarra, saw the Niger, travelled five hundred miles with a slave-merchant, reconnoitred the Gambia River, and returned to England in 1797. He again set out, on the 30th of January, 1805, with his brother-in-law Anderson, Scott, the designer, and a gang of workmen; he reached Gorea, there added a detachment of thirty-five soldiers to his party, and saw the Niger again on the 19th of August. But, by that time, in consequence of fatigue, privations, ill-usage, the inclemencies of the weather, and the unhealthiness of the country, only eleven persons remained alive of the forty Europeans in the party. On the 16th of November, the last letters from Mungo Park reached his wife; and, a year later a trader from that country gave information that, having got as far as Boussa, on the Niger, on the 23d of December, the unfortunate traveller’s boat was upset by the cataracts in that part of the river, and he was murdered by the natives.” “And his dreadful fate did not check the efforts of others to explore that river?” “On the contrary, Dick. Since then, there were two objects in view: namely, to recover the lost man’s papers, as well as to pursue the exploration. In 1816, an expedition was organized, in which Major Grey took part. It arrived in Senegal, penetrated to the Fonta-Jallon, visited the Foullah and Mandingo populations, and returned to England without further results. In 1822, Major Laing explored all the western part of Africa near to the British possessions; and he it was who got so far as the sources of the Niger; and, according to his documents, the spring in which that immense river takes its rise is not two feet broad. “Easy to jump over,” said Joe. “How’s that? Easy you think, eh?” retorted the doctor. “If we are to believe tradition, whoever attempts to pass that spring, by leaping over it, is immediately swallowed up; and whoever tries to draw water from it, feels himself repulsed by an invisible hand.” “I suppose a man has a right not to believe a word of that!” persisted Joe. “Oh, by all means!—Five years later, it was Major Laing’s destiny to force his way across the desert of Sahara, penetrate to Timbuctoo, and perish a few miles above it, by strangling, at the hands of the Ouelad-shiman, who wanted to compel him to turn Mussulman.” “Still another victim!” said the sportsman.