On his arrival in London in September 1804, Park presented a written statement to the Colonial Office embodying his views as to the commercial and geographical results likely to accrue from the intended expedition, at the same time pointing out the best means to accomplish the work as regards men and goods. In this memorandum he pointed out the course he proposed to pursue. Passing through Bondu, Kajaaga, Fuladu, and Bambarra to Sego, he would construct a boat and proceed by way of Jenné and Kabara (the port of Timbuktu) through the kingdoms of Haussa, Nyffé (now called Nupé), and Kashna, &c., to the kingdom of Wangara. If the river ended here, he pointed out, his chief difficulty would begin. To return by the Niger, to cross the desert to Tripoli or Egypt, or to pass eastward to the Nile and Abyssinia, he considered equally difficult. The most feasible course seemed that towards the Bight of Benin. If, however, the Niger was, as he confidently believed, in reality the Congo, he would follow it to its termination. After pointing out the grounds for his belief, Park concluded with the opinion that when “your Lordship shall have duly weighed the above reasons, you will be induced to conclude that my hopes of returning by the Congo are not altogether fanciful, and that the expedition, though attended with extreme danger, promises to be productive of the utmost advantage to Great Britain. Considered in a commercial point of view, it is second only to the discovery of the Cape of Good Hope, and in a geographical point of view is certainly the greatest discovery that remains to be made in the world”—a very strong statement of the case, it must be admitted, though undoubtedly if the Niger and the Congo had proved to be one, it could scarcely have been said to be too strong.

Park had been converted to this view of the identity of the two great rivers by one George Maxwell, a West African trader, who had seen much of the Congo near its mouth, and had published a chart embodying the results of his observations. When closely examined, the arguments in its favour were of small value, and practically arose out of the fact that there was a large river with a southerly trend whose termination was unknown, while further south there was a second, the Congo, whose origin was equally a mystery. Prolong these in the necessary direction and the result is identity, and the mystery of both is settled.

Meanwhile Major Rennell stuck to his view with all the pertinacity of the arm-chair geographer, and the man of one idea. For him the Niger ended in the desert wastes of Wangara and Ghana. Unfortunately for his theory the Major was unconsciously confounding two Wangaras separated from each other by fifteen hundred miles and more, and likewise the old Empire of Ghana on the middle course of the Niger with Kano at the eastern extremity of the Haussa States. A similar confusion also appears in Park’s memorandum, where he speaks of the continuation of the river after Nupé to Kashna (Katsina) and the kingdom of Wangara.

Strange indeed it seems to us now that no geographer even at this time ever suggested that the outlet of the Niger might be in the Bight of Benin, among the numerous creeks that penetrate the low swampy mangrove ground which here subtends the Bight. Looking at the map, the suggestion seems to us to come naturally, yet Park had to carry the course of the river away south to the Congo; Rennell turned it west, and ended it where our maps are now occupied by Lake Chad, while there were not wanting others, like Jackson, who persisted in joining it to the Nile, “en abusant, pour ainsi dire, du vaste carrière que l’intérieur de l’Afrique y laissait prendre,” as D’Anville had said of earlier geographers.

Whatever we may now think of Park’s theories as to the termination of the Niger, they did not appear in any way absurd in his own time. The wildest conjecture was permissible as regards a vast river flowing by an uncertain course through a continent still blank on our maps. Accordingly his memorandum was received favourably by Lord Camden, and the despatch of the expedition to carry out the traveller’s ideas was determined on.

A liberal compensation was to be given to Park on his return, and it was also stipulated that in the event of his death, or of his not being heard of within a given period, a certain sum should be paid by Government as a provision for his wife and family.

Meanwhile Rennell, in the most friendly fashion, not only argued against Park’s views as to the Niger termination, but earnestly advised him to relinquish his dangerous project. With as little effect in the one case as in the other, however. The explorer’s determination, like his opinions, was not to be shaken. Sir Joseph Banks took up a more philosophic position. He admitted the hazardous nature of the enterprise; but since the work was not to be accomplished without risk of life, he could not attempt to dissuade Park from it, he being the man most likely to carry it through with least danger of a fatal issue.

Gradually the affairs of the expedition began to take shape. Dr. Alexander Anderson, Park’s young brother-in-law, was selected as his second in command, and Mr. George Scott, a fellow-dalesman, was added to the party as draughtsman. A few boat-builders and artificers were also to accompany the party from England, for the purpose of constructing the boat intended for the navigation of the Niger when it was reached. Soldiers to assist and protect the expedition were to be selected at Goree, where a garrison of the African corps was stationed.

It was now a matter of paramount importance that the expedition should leave England at once if it was to take advantage of the dry season. But official red-tape was as difficult to galvanise into activity and life as African apathy, and in spite of his utmost endeavours to push matters on, delay succeeded upon delay, and Park saw the good season gradually dwindling away, leaving him to the maddening contemplation of all the additional difficulties and dangers engendered by the rains. Two whole months were thus lost; and when he at last received his official instructions, he knew that the Government, by its continued procrastination, had done much if not everything to ensure a disastrous termination to the expedition.

In the instructions supplied to him Park’s mission was defined as being to discover whether and to what extent commercial intercourse could be established in the interior of Africa for the mutual benefit of the natives and of His Majesty’s subjects. He was directed to proceed up the Gambia, and thence to the banks of the Niger by way of the Senegal. The special object of his journey was to determine the course of the Niger, and to establish communication with all the different nations on its banks. He was at liberty to pursue any return route which he might find most suitable, either by turning west to the Atlantic, or by marching upon Cairo.