Köchel catalogue Horn Concerto No. 1, K. (412+514)/386b. In the decades after Mozart's death there were several attempts to catalogue his compositions, for example by Franz Gleißner and Johann Anton André (published in 1833), but it was not until 1862 that Ludwig von Köchel succeeded in producing a comprehensive listing. Köchel's 551-page catalogue was titled "Chronologisch-thematisches Verzeichnis sämmtlicher Tonwerke W. A. Mozarts" ("Chronological-thematic Catalogue of the Complete Musical Works of W. A. Mozart"). Köchel attempted to arrange the works in chronological order, but many compositions written before 1784 could only be estimated, although Leopold Mozart had compiled a partial list of his
19th century in science later in the 19th century by the German mathematician Bernhard Riemann; here no parallel can be found and the angles in a triangle add up to more than 180°. Riemann also developed Riemannian geometry, which unifies and vastly generalizes the three types of geometry. The 19th century saw the beginning of a great deal of abstract algebra. Hermann Grassmann in Germany gave a first version of vector spaces, William Rowan Hamilton in Ireland developed noncommutative algebra. The British mathematician George Boole devised an algebra that soon evolved into what is now called Boolean algebra, in which the only numbers were