The principal details of the intended expedition had been fully considered, and in a great measure arranged, in the Colonial department, before the application was made to Park; and he had therefore flattered himself that the business was in a state of considerable forwardness. But on his arrival in London, he was much disappointed to find that the sailing of the expedition had been postponed; and it was not till after two months that his departure was finally appointed for the end of February, 1804. But, unfortunately, when this period arrived, the apprehension of important political changes, which eventually took place by the resignation of Mr. Addington a short time afterwards, caused some embarrassment in the measures and proceedings of the Administration. After all was ready at Portsmouth for the embarkation, and part of the troops destined for the service were actually on board, the expedition was suddenly countermanded; and the question, whether it should finally proceed to Africa or not, was reserved for the decision of Lord Camden, who shortly afterwards succeeded to Lord Hobart in the Colonial department. In consequence of this change, Park was informed at the Colonial Office, that the expedition could not possibly sail before September; and it was suggested to him by some person in authority, that he might employ the interval with great advantage in improving himself in the practice of taking astronomical observations, and in acquiring some knowledge of the Arabic language. He was at the same time informed, that any reasonable expence which he might incur in acquiring this instruction would be reimbursed to him by Government. In consequence of this intimation, he engaged a native of Mogadore, named Sidi Omback Boubi, then residing in London, who had served as the interpreter of Elphi Bey, (the ambassador of the Mamelukes from Cairo) to accompany him to Scotland, for the purpose of instructing him in Arabic. They immediately left London together, and arrived early in March at Peebles; where Park continued to reside together with his African instructor, till about the middle of May. He then finally quitted his house at Peebles, and took his family to the farm at Fowlshiels, where he quietly waited the expected summons of the Secretary of State. During all this time he employed himself with great diligence in acquiring a familiar use of astronomical instruments, and in the study of the Arabic language, in which he became a tolerable proficient. Early in September he received a letter from the Under Secretary of State for the Colonial department, desiring him to set off without delay for London, and to present himself on his arrival at the Colonial Office. He accordingly lost no time in settling his affairs; and taking an affectionate leave of his family, wife, and children, quitted Fowlshiels, and arrived in London towards the latter end of September, 1804.