Object, Instrument, Technology

The vibration microscope is an electromagnetically-driven adaptation by Hermann von Helmholtz (1821-1894) of the earlier optical comparator by Jules Antoine Lissajous (1822-1880). The device allows one to determine the frequency of a tuning fork or other vibrating object with respect to a fork of known frequency, by way of Lissajous figure analysis.

Object, Instrument, Technology

Organ pipes came in a variety of forms, each producing desired overtones.

(1901) 1901. Dingler's Polytechnisches Journal 316: 485–490.
Object, Instrument, Technology

In 1894, Olaus Henrici (1840-1918) of London devised a harmonic analyzer for determining the fundamental and harmonic components of complex sound waves. It consists of multiple pulleys and glass spheres, called rolling-sphere integrators, connected to measuring dials. The image of a curve (for example, a phonodeik tracing of a sound wave) is placed under the device. The user moves a mechanical stylus along the curve’s path, tracing out the wave form.

Contributor essay
David Pantalony; Erich Weidenhammer; Victoria Fisher

The University of Toronto acoustics collection consists of a comprehensive series of instruments made in the Parisian workshop of Rudolph Koenig (1832