The stop action is mechanical
By a set of kneecaps and set squares, the movement is passed on in 90 °, towards levers on the sides of the windchest.
The ratio enters the movement of the stop in the facade and the movement of the slider is 8/50.
At the letf side : Grand-Orgue stops
Positif sliders levers forms
The mechanics of the chimney flute 8' passes outside the windchest