Wheatstone's rods \Wheat"stone's rods\ (Acoustics)
Flexible rods the period of vibration of which in two planes
at right angles are in some exact ratio to one another. When
one end of such a rod is fixed, the free end describes in
vibrating the corresponding Lissajous figure. So called
because devised by Sir Charles Wheatstone.
[Webster 1913 Suppl.]