Accession No

6229

Brief Description

set of four tuning forks for the production of Lissajous figures by reflection, by Rudolph Koenig, French, 1870 (c)

Origin

France; Paris

Maker

Koenig, Rudolph

Class

sound

Earliest Date

1855

Latest Date

1901

Inscription Date

Material

metal (brass; steel); wood (teak?); glass

Dimensions

[set in box] width 405mm; depth 200mm; height 88mm

Special Collection

Provenance

Purchased from an individual seller at the 44th International Scientific Instrument Fair, Marble Arch, 20/04/2008.

Inscription

[All four tuning forks contain Koenig’s makers mark:] RK
[On largest tuning fork:]
UT1
128 vs
[On second largest tuning fork:]
SOL1
192 vs
[On third largest tuning fork]
SOL1
192 vs
[On smallest tuning fork:]
UT2
256 vs

Description Notes

Set of four tuning forks for the production of Lissajous figures by reflection, by Rudolph Koenig, c. 1870.

Four tuning forks of different sizes, each with a small circular mirror attached to the end of one prong of the fork (and a brass counterweight attached to the end of the other prong). Handle bar contains sliding wooden handle plus a brass screw attachment, enabling the tuning fork to be screwed into a stand (stand not present with this set).

All four forks come in a fitted wooden box.

Complete

References

Torben Rees; 'Lissajous tuning forks: the standardization of musical sound'; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge; 2010: https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/acoustics/lissajous-tuning-forks-standardisation-musical-sound

Events

Description
This set of tuning forks is part of an apparatus designed in 1855 by the French physicist Jules Antoine Lissajous for the visualization and analysis of sound vibrations. This particular set of forks was manufactured by Rudolph Koenig, a Parisian physicist and maker of acoustical scientific instruments. It was used for educational demonstrations and also for the fine calibration of tuning forks.

Each tuning fork has a small mirror mounted at the end of one prong (tine), counterbalanced at the other by a small mass of equal weight. To perform a demonstration experiment, the forks are arranged at right angles in a frame (not present here) so that one vibrates in the North-South direction and the other in the East-West direction. A single light beam is reflected from one mirror to the next and then projected onto a screen. The light beam is thus periodically displaced in two dimensions and will trace on the screen a curve, whose geometric properties depend on the frequencies, phase and amplitude of vibration of the forks. ‘Lissajous figures’ of great beauty and complexity can be produced in this way and the most stable and perfect only appear when the two forks vibrate at frequencies of specific ratios. By pairing an unfinished tuning fork with a fork of a known standard frequency it is possible to make fine tuning adjustments by viewing the Lissajous figures—adjustments that were much more precise than those that could be performed by the ear alone.

Lissajous performed his work on tuning forks during the second half of the nineteenth century. This was a period of great enthusiasm for standardization in science, and the science of acoustics was no exception. However, the world of music was also crying out for standardization and in particular musicians and musical instrument makers wanted a standard for pitch. In 1858 the French government set up a commission charged with setting such a standard. Lissajous was a member of this committee, which also featured great composers such as Berlioz and Rossini.
09/07/2008
Created by: Torben Rees on 09/07/2008

FM:46702