SAVART'S TONE WHEELS ALLOY C/W 10/6mm DIA. STEM
The 'Savart's Tone Wheel' consists of 4 metal discs about 73mmD, mounted on a central shaft so that the set of 4 can be rotated. Each disc has a different number of teeth cut into it so that when a stiff card is placed against the edge of a wheel, a tone is produced.
The teeth are 36, 45, 54 and 72 and this is a ratio of 4, 5, 6, and 8. The combined sound of all 4 discs touching the stiff card is a natural musical chord.