Hi All, A customer has what's turning out to be a rather strange
Aeolian 65-note Themodist circa 1906 in a upright piano. It is
a strictly foot-pumped unit. The attached pictures show what's
in the lower half of the piano and under the keys.

While I believe I've figured out where all of the tubing goes
(see tubing diagram), I've yet to figure out how the Themodist
system operates. Among other things, am I correct is stating
that the Themodist perforations should cause the volume of the
music to increase?

Also, does this system have an air motor governor? (I can't
find one.)

And referring to the picture of the Stack Vacuum, when vacuum
is connected to point C, all of the notes play. When vacuum
is connected to point D, the notes behave as seen in the video.
See https://www.player-care.com/aeolian/stack-test.MOV 

Any help understanding this system will be greatly appreciated.

Musically,

John A Tuttle
Player-Care
Brick, NJ, USA

Attachments:

[ 65-note Themodist lower section
[ https://www.mmdigest.com/Attachments/26/08/10/260810_200200_Below_Keybed_1.jpg
 

[ 65-note Themodist under the keys
[ https://www.mmdigest.com/Attachments/26/08/10/260810_200200_Under_keys_in_keybed.jpg
 

[ 65-note Themodist tubing diagram
[ https://www.mmdigest.com/Attachments/26/08/10/260810_200200_Tubing_Diagram.jpg
 

[ 65-note Themodist Stack Vacuum
[ https://www.mmdigest.com/Attachments/26/08/10/260810_200200_stack-test.jpg