« N.1 » probably refers to the fact that horns were often sold by pairs1. « C. A. Ziegler » is more mysterious. It could be either the name of the owner/player, or the name of the dealer2. I did not find any trace of a horn player named Ziegler. In the Langwill Index however, several makers are listed. None of them have the initials « C. A. » in their names ; but one does have the initial « C. ». It could be the same Ziegler without the middle name ; there is no certitude at all.
This C. Ziegler was registered as a woodturner in Vienna3. If this is the same man, we can imagine that this horn was actually once sold in Vienna ! This would have of course happened somewhere in or after 1798, long after Mozart died ; but the horn is then not so irrelevant, it was once played in Mozart’s city shortly after his death. This is only a hypothesis, more investigation is to be conducted on this C. A. Ziegler.
To begin with, I had the great chance to have a close look at a beautiful Haltenhof French horn dated 1798 from The Hague’s Kunstmuseum (number 0840286)4. This instrument is German, made after Mozart’s death and is an early French style horn. It is then a very good exemple of what Mozart did not know, which is yet not irrelevant : it is like a compass pointing to the south.
The bell diameter is 28,5 cm. It is a typical large German bell as opposed to the Viennese instruments. As a result, the sound was large and mellow, even with the B-flat crook (the only crook available, therefore I couldn’t play some Mozart on it). The horn was easy-blowing, with few resistance, which makes me think that viennese instruments may have been different with their smaller bells, allowing an easier high range (which is about to be confirmed in the following).
