Harmonie-Hammerfluegel [was: Cittern]

Wim Hoogewerf wrote:
> In the same Kunsthistorisches Museum there was also a
> Harmonie-Hammerfluegel, by Johann Jakob Koennicke (Vienna, 1776).
> This instrument, presented as being "31-tone", was played by
> Beethoven and Schubert. Mozart himself had one built.

I remember a recording of the Forelle (Trout) Quintet with
a Hammerfluegel. That tuning did not strike me as unusual.

I had no idea that 31-tone tuning would be used by these
composers. (Imagine finding a piece by Mozart for a 31-ET
mechanical glass harmonica!) I am very interested in any related info
or leads for study.

I am not sure I understand the description of the instruments, yet.
How are the six manuals positioned?

Best Regards,
- George Kahrimanis anakreon@hol.gr