In 1745 Hume became tutor to a young nobleman, the Marquis of Annandale, who was mentally affected, but he did not endure the engagement for long. Next year General St. Clair, who had been appointed to command an expedition in the War of the Pragmatic Sanction, invited him to be his secretary, an office to which that of judge-advocate was afterwards added. The expedition was a failure, but General St. Clair, who was afterwards entrusted with embassies to Turin and Vienna, and upon whom Hume seems to have created a favourable impression, insisted that he should accompany him in the same capacity as secretary; he further made him one of his _aides-de-camp_. Thus Hume had to attire his portly figure in a "scarlet military uniform," and Lord Charlemont who met him in Turin says that he wore his uniform "like a grocer of the train-bands." At Vienna the Empress-Dowager excused him on ceremonial occasions from walking backwards, a concession which was much appreciated by "my companions who were desperately afraid of my falling on them and crushing them." Hume returned to London in 1749. "These years," he says, "were almost the only interruptions my studies have received during the course of my life. I passed them agreeably and in good company, and my appointments, with my frugality, had made me reach a fortune which I called independent, though most of my friends were inclined to smile when I said so; in short, I was now master of near a thousand pounds." While Hume was away with General St. Clair his _Inquiry Concerning Human Understanding_ was published, but it was not more successful than the original _Treatise_ of a portion of which it was a recasting. A new edition of _Moral and Political Essays_ met with no better fate, but these disappointments, he says, "made little or no impression" on him. In 1749 Hume returned to Ninewells, and lived for a while with his brothers. Afterwards he took a flat of his own at Edinburgh, with his sister to keep house for him. At this period the _Political Discourses_ and the _Inquiry concerning the Principles of Morals_ were published. Of the _Inquiry_ Hume held the opinion, an opinion, however, which was not shared by the critics, that "it is of all my writings--historical, philosophical, or literary incomparably the best." Slowly and surely his publications were growing in reputation. In 1752 the Faculty of Advocates elected Hume their librarian, an office which was valuable to him, not so much for the emolument as for the extensive library which enabled him to pursue the historical studies upon which he had for some time been engaged. For the next nine years he was occupied with his _History of England_. The first volume was published in 1754, and the second volume, which met with a better reception than the first, in 1756. Only forty-five copies of the first volume were sold in a twelvemonth; but the subsequent volumes made rapid headway, and raised a