The physharmonica is a keyboard instrument fitted with free reeds, a kind of harmonium much used in Germany in the early 20th century.
[1] The physharmonica resembles a small harmonium, but is differentiated from it by having no stops, being without percussion action, having only a 4 octave compass, and not speaking readily or clearly.
As with the harmonium, the bellows are worked by the feet by an alternate movement, which also affords a means of varying the dynamic force of the tone according as more or less energetic pedalling increases or decreases the pressure of the wind supply.
[1] The physharmonica was invented in 1818 by Anton Haeckl, of Vienna; in the original instrument the bellows were placed right and left immediately under the shallow wind-chest, and were worked by means of pedals connected by stout wire.
[1] A patent for improvements to this type of instrument was granted to Anton Reinlein 1824.