When he had studied the mathematics, during two years, under Büsch, he removed to Göttingen, where he continued another year. At this period the Danish ministry, at the suggestion of Michaelis, had projected a scientific expedition into Arabia, which was at first designed, at least by its originator, merely to throw some light upon certain passages of the Old Testament, but which afterward embraced a much wider field. Michaelis, to whom the choice of the individuals who were to form this mission had been intrusted, betrayed the narrowness or malignity of his mind, by neglecting the celebrated Reiske, who was then well known to be struggling with starvation, in order to thrust forward Von Haven, a pupil of his own, who, but for this partial choice, would probably have lived and died in obscurity. Niebuhr himself was recommended to Michaelis by Kästner, whose pupil he had for some time been. The proposal was abruptly made, and as suddenly accepted. “Have you a mind,” said Kästner, “to go into Arabia?”--“Why not?” replied Niebuhr, “if anybody will pay my expenses.”--“The King of Denmark,” said Kästner, “will pay your expenses.” He then entered into the history of the Danish ministry’s project, and Niebuhr, whose genuine ambition was most ardent, and who, though in manners modest and unassuming, could not but entertain a favourable opinion of his own capacity, at once engaged to form a member of the mission. It was agreed, on the part of his Danish majesty, that he should be allowed a year and a half for preparation, with a salary sufficient for his maintenance. Niebuhr had now a definite object. The East, with all its barbaric pomp and historical glory, which in preceding and succeeding days have kindled enthusiasm in so many bosoms, appeared to court his examination; and, like a lover who appreciates at their highest value the accomplishments of his mistress, and is bent on rendering himself worthy of her, he thenceforward studied, with vehement earnestness, all those branches of knowledge which he regarded as necessary to a traveller in the East; and Latin, Arabic, the mathematics, drawing, practical mechanics, together with the history of the countries he was about to visit, amply occupied his hours. An additional half-year being granted him, it was not until the Michaelmas of 1760 that he quitted Göttingen for Copenhagen.