Vibration Microscope

Rudolph Koenig

The vibration microscope (or optical comparator) was used to calibrate the frequency of a tuning fork in terms of a fork of known frequency. Hermann von Helmholtz invented the form; Jules Antoine Lissajous introduced that in which the reference fork is driven electromagnetically. This electromagnetic example is inscribed “Rudolph Koenig a Paris” and was used at the U.S. Military Academy at West Point.