Clock/Foucault pendulum, Bravais pendulum (n° 21)

This combo has three distinct functions:

  1. To tell the time. This involves one metre of pendulum length, regulated to compensate for differences in length due to temperature variations.
  2. To indicate and measure the rotation of the earth by oscillating freely like any Foucault pendulum.
  3. Measure the speed of rotation of the earth if used as a conical pendulum.