The Buschmanns knew of an instrument built at about this time by Johann Caspar Schlimbach, an instrument maker trained in Vienna, and his cousin Bernhard Eschenbach in Königshofen in Bavaria: this was a pianoforte with an aeoline register. Schlimbach made no attempt to protect his invention, but freely showed the instrument to everyone who wanted to see it, with the inevitable result that a number of people patented very similar instruments in Vienna. Indeed, Buschmann's father Johann wrote in a letter of 30 October 1829 that he was thinking of taking out a patent for the new instrument in Bavaria.