| The 1889 Koenig catalogue lists this as catalogue number
118, "circular paper membrane, 30 cm in diameter .. 11 francs"; the
Queen catalogue for the same year lists it at $2.00. The membrane is designed
to show Chladni figures. The source of the sound is an elliptical
bell that is set in motion by drawing a rosined violin bow across its
edge. Thin rubber can also be used as a membrane.
The apparatus is in the collection at Amherst College. On the right hand side can be seen the ACPL (Amherst College Physics Laboratory) number that I remember so well from my undergraduate days in the later nineteen fifties. Just above this is Koenig's name stamp.