It was in December 1831, that Messrs. Coulthurst and Tyrwhitt were introduced to the council of the Geographical Society, as being about to proceed at their own expense to the mouth of the Quorra, with the view of endeavouring to penetrate thence eastward to the Bahr-Abiad; and although their preparations were not on such a scale as to warrant any very sanguine hopes of success, yet it was felt to be a duty on the part of the society to patronize so spirited an undertaking.  They were accordingly placed in communication with Colonel Leake, and other members of the late African Association, whose advice it was thought could not fail to be of service to them.  They were also introduced to Captain Owen and to Mr. Lander, the value of whose experience in planning their operations was obvious.  And the expedition being brought under the notice of his majesty’s government, the loan of a chronometer was obtained for it, with strong letters of introduction and recommendation to the officers commanding the naval and military forces of the crown along the African coast.

The party sailed from the Downs on the 1st January 1832, and arrived at Bathurst St. Mary’s on the Gambia on the 28th of the same month.  Both travellers were somewhat indisposed during the voyage, and the sun after their arrival so seriously affected Mr. Tyrwhitt, that he here yielded to the repeated representations of his companion and others, and returned home.  The following is an extract of a letter received from Mr. Coulthurst, dated Bathurst, 1st February 1832, and the style is clearly indicative of the superior qualifications of his mind: 

“After a conference and palaver with some of the native chiefs, amongst whose grotesque forms and equipments you would have laughed to have seen me perched this morning, sipping palm wine; I have made up my mind to take the southern bank of this river, through Fooladoo to Sego.  A messenger from the Almana of Bondou, who has undertaken to bring the gum trade here from the Senegal, is now at Bathurst, and the merchants are willing to assist in making up a coffila, which will enable us I trust to prosecute our journey in safety.  Though I shall not thus reach the main object of Funda so directly as if I had had the good fortune to overtake the Pluto, it would be scarcely possible for me to do this now before the rainy season; and though I shall be a few weeks later in reaching my destination, I shall have the satisfaction of tracing the whole river, and giving the position of all the remarkable places, which neither Caillie nor Lander were able to do.  There is now no earthly chance of the observations made by Park seeing the light, for Mr. Ainslie showed me yesterday his last letter from Sansanding, which I perused with much interest.  You are aware that nothing but the unfortunate occurrence of the Fellatas’ conquests with the period of his expedition, and his being mistaken for one of their parties, occasioned its unhappy result; and by striking across the mountains, which we shall do at Baranco, about four hundred miles up, we shall have only twenty-four days’ land journey to the mighty Niger, where he has scarcely command of water enough to float a canoe.