Besides these compositions, a Trio for Pianoforte, Flute and Bassoon,[56] concerning which all the information which we have came from the catalogue of Beethoven’s effects sold at auction, has recently been published. It is No. 179 in the catalogue, where it is described as a composition of the Bonn period. On the autograph, preserved in Berlin, the title, placed at the end, is “Trio concertante a clavicembalo, flauto, fagotto, composto da Ludovico van Beethoven organista di S. S. (illegible word), cologne.” The designation of the composer as organist, etc., fixes the place of its origin, and the handwriting indicates an early date. Among the papers found in Beethoven’s apartments after his death, was the manuscript of a Sonata in B-flat for Pianoforte and Flute, which passed into the hands of Artaria. It is not in Beethoven’s handwriting, and the little evidence of its authenticity is not convincing.[57] It is more than likely that the Variations for Pianoforte and Violin on Mozart’s “Se vuol ballare” ought to be assigned to the latter part of the Bonn period. They were published in July, 1793, with a dedication to Eleonore von Breuning, to whom Beethoven sent the composition with a letter dated November 2, 1793.[58] The dedication leads to the presumption that the work was carried to Vienna in a finished state and there subjected to only the final polish. The postscript to the letter to Fräulein von Breuning betrays the reason for the hurried publication: Beethoven wanted to checkmate certain Viennese pianists whom he had detected copying peculiarities of his playing in improvisation which he suspected they would publish as their own devices. Besides the pieces already mentioned, Beethoven wrote the following works for pianoforte in Bonn: 1. A Prelude in F minor.[59] According to a remark on a printed copy shown to be authentic, Beethoven wrote it when he was 15 year old, that is, in 1786 or, the question of his age not being determined at the time, 1787. The prelude is, as a matter of fact, a fruit of his studies in the art of imitation; and the initiative, probably, came from Bach’s Preludes. 2. Two Preludes through the Twelve Major Keys for Pianoforte or Organ; published by Hoffmeister in 1803 as Op. 39. Obviously exercises written for Neefe while he was Beethoven’s teacher in composition.