An early (circa 1870) signed Cammann binaural stethoscope with the chest piece, ear pieces and joints made from gutta percha.
It still has the original elastic tension band for retaining the tubes in position. This was the first tension mechanism used by Cammann and was later replaced with various spring loaded devices. The flexible tubing is woven in fine silk. Signed on the bridge “Dr Cammann’s Stethoscope Tiemann & Co”.