Bowles Collection
The Bowles’ stethoscope provided better sound and a non-compressible stem (the part that connects to the tubing). Stems made of compressible material, like flexible rubber, could be bent. This interrupted sound to the earpieces. In his patent, Bowles noted that the incompressible stem allowed physicians to listen for heart and lung sounds without requiring patients to remove their clothing (A useful feature during the modest Victorian era). It would have also been useful when trying to monitor an anesthetized patient without disrupting the surgical team. Robert Bowles applied to patent the original version of his stethoscope in 1897. The patent was granted in 1901. Four of his other modifications were patented by 1904.
Bowles stethoscope patent, 1901
A Pilling Special Bowles Patent stethoscope with original rubber tubing, circa 1901. The stethoscope belonged to Dr. William F. Muhlenberg, great, great grandson of Henry Melchoir Muhlenberg, the founder of the Lutheran Church in America.
The Bowles diaphragm chest pieces came in midget, small, medium and large sizes and with one or two connection tubes. Shown above are the midget two tube, medium (regular) two tube and large one tube size chest pieces .
The Bowles chest piece was designed with concentric circular grooves to enhance transmission of sound from the diaphragm into the tube connecting to the ear piece. Shown above starting from the left is the chest piece with 1. metal protective cover clipped on, 2. plastic diaphragm in place and 3. plastic diaphragm removed to reveal the grooves.