





Eight brass toothed wheels with different numbers of teeth, on a central brass spindle, by William Ladd, London, England, 1870. Used in Savart's apparatus for producing sounds of known frequencies (see note).
The relationship between the radii of these wheels also makes visible the ratio of frequencies in a major scale. Felix Savart was a surgeon in Napoleon’s army before becoming interested in physics. In 1830 he invented this simple device which links the frequency of vibration of sound to pitch. If the wheels are rotated along their central axis, and a card held against the teeth, a musical note is emitted – but unlike the tuning forks the largest wheel gives the highest note.
Details
- Category:
- Acoustics
- Object Number:
- 1872-9
- Measurements:
-
standing upright: 130 mm 85 mm, .905kg
- type:
- savart's wheel
- credit:
- Ladd, W.