|| The apparatus at the left is listed in the 1889 Koenig
catalogue as "Five parallel rods joined together ... 50 fr [about $10]".
It is on display at the University Museum at the University of Mississippi in Oxford. The placard notes that the device was invented by Savart.
The five parallel rods are held at the middle, which will
be a node for transverse waves. But, when the top bar is set vibrating,
all of the remaining bars will also vibrate, a clear demonstration that
the sound transmitted through the air is setting the bars in motion.