Handharmonium
System: Gerl (unisonoric, logical)
(Collection Oriwohl, Nr. 146)
System: Dr.med. Franz Michael Gerl (Hindelang in Bavaria), Patent dated 6 Dec. 1891
Single-tone harmonica (i.e. without chord keys as on the accordion). Both manuals are constructed identically (same fingering pattern), but with opposing tone direction and the resulting different fingerings.
The instrument type seems to be the first single-tone model after the English concertina, which is unisonoric on both sides and has a consistently logical keyboard system.
Left side:
Vertical interval in all rows is a minor third. Overall similar to the Bb-system on the accordion, only with rows shifted by one or two keys.
Between the keys and the hand rest is the air key control that runs the entire length of the manual.
Right side:
Like manual left with opposite tone direction.
Using the horizontal slots, the hand rest can be moved to the keys according to the individual finger length.
The vertical adjusting screws can be used to set the distance between the hand rest and the manual.
Right side inside:
The air key mechanism is located to the left of the three soundposts.
The hand rest can also be tilted or turned in to the manual.
All in all, a very variable design that allows you to move comfortably over the entire length of the manual.
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