The existence of the great river Niger, had been established by the concurrent testimony of all navigators, but of its course or origin, not the slightest information had been received. The circumstance of its waters flowing from the eastward, gave rise to the conjecture, that they flowed through the interior of the continent, and emptied themselves either by the Senegal or the Gambia, into the Atlantic. It was, therefore, considered probable, that by ascending the Senegal or the Gambia, which were supposed to be merely tributary streams of the Niger, of which they formed the estuary, that Timbuctoo and the country of gold might be reached; and so strongly was this opinion impressed upon the minds of the merchants, and other adventurers, that a journey to Timbuctoo became the leading project of the day, and measures were accordingly taken to carry it into execution. The first person sent out by the company established for exploring the Gambia, was Richard Thompson, a Barbary merchant, a man of some talent and enterprise, who sailed from the Thames in the Catherine, of 120 tons, with a cargo valued at nearly two thousand pounds sterling. The expedition of Thompson was unfortunate in the extreme, but the accounts received of his adventures and death, have been differently recited. It is certain, that Thompson ascended the Gambia as far as Tenda, a point much beyond what any European had before reached, and according to one account, he was here attacked by the Portuguese, who succeeded in making a general massacre of the English. Another account states, that he was killed in an affray with his own people, and thence has been styled the first martyr, or more properly the first victim in the cause of African discovery. The company, however, nothing daunted by the ill success of Thompson, despatched another expedition on a larger scale, consisting of the Sion of 200 tons, and the St. John of 50, giving the command to Richard Jobson, to whom we are indebted for the first satisfactory account of the great river districts of western Africa.