8270. Wirsching, P. April 14. Automatic instruments.-In an automatically - operated organ having several organ divisions, mechanism is provided whereby the performer may produce solo or obligato effects upon one organ division, and allow the accompaniment to be played upon another organ division or not, as required. Each of the apertures 5 in the tracker board 4 communicates with a pneumatic 7 in the exhaust chamber 8, beneath which are arranged bellows 9, controlled by springs 11, the tension of which is adjustable, and provided with pallets 10. The pallets 10 control apertures in action bars 15, 16, of which there may be one for each organ division, each being connected by a tube 19 or 20 to the intermediate station. The valve chamber 21 of the action bar 15 contains membrane valves 22, or a sheet of flexible material which serves the same purpose, controlling ports leading to the wind-way 17. The chamber 21 is connected by a pipe 23 to a duct 28, leading to a box containing wind under pressure. In the action bar 16, chambers 32 are arranged for each note, and are provided with membrane valves 33 adapted to establish communication between the two sections of each wind-way 17. Adjacent to the keyboard, two valves such as 34 are placed, and are adapted to slide upon a seating 36 having apertures 38 in communication with chambers 32. The valves 34, which are preferably made of hard rubber, are formed of two grooved portions connected by a flexible portion 43, and are charged with air by the pipes 42. Handles 47 and tracers in proximity to the tune-sheet are provided for each valve. When air is admitted to a port 5, the pneumatic 7 expands, connecting the bellows 9 to exhaust, thus opening the ducts 17 to the atmosphere and thereby causing the corresponding pipes to speak. To silence the accompaniment, the performer presses the piston 31, opening a valve 30 so that the pneumatic 25 collapses and the chamber 21 is connected to the chamber 24, thus admitting air under pressure to the chamber 21 and closing all the valves 22. When all the ducts 38 are covered by the valves 34, the air in all the chambers 32 is under pressure and the valves 33 are closed. If a duct 38 is opened to atmosphere by movement of valves 34, the air from the corresponding chamber 32 escapes and the duct 17 is exhausted. It is thus possible to silence all the notes of this organ division or to sound any particular notes, which may be indicated on the tune-sheet by a line, for producing obligato or solo effects. The chamber 21 may be divided into compartments so that the notes of the first organ may be sounded in octaves, and one of the valves 34 may be used to silence all the bass notes of the second organ. The apparatus may be operated either by pressure or suction alone, and only one valve 34 may be provided.