Signedstamped on the collar: RK
Inscribedstamped on the collar: MI 4 RK
FunctionResonators were tone detectors, being tuned to respond to specific frequencies of sound. Similar to an astronomer or chemist using a prism to separate light into the elemental colors that composed the source, Hermann von Helmholtz used a bank of resonators in order to analyze sounds into their elemental tones. Resonators were used to confirm Ohm's theory that complex sounds were the Fourier sum of simple sinusoidal sound waves or harmonics.
A video demonstration of the Helmholtz resonator was produced by the Smithsonian's National Museum of American History and is on YouTube.
Historical AttributesThis is one of set of ten, brass, Helmholtz resonators in series purchased from Rudolph Koenig for Harvard's Psychology Laboratory in 1891. The set is listed in Hugo Münsterberg's 1893 World's Fair pamphlet, "Psychological Laboratory of Harvard University" as a "series of ten resonators. After Helmholtz, by Koenig, Paris. $35."
Primary SourcesRudolph Koenig, Catalogue des appareils d'acoustique, (Paris, 1889), 54, no. 25.
Hugo Munsterberg, Psychological Laboratory of Harvard University (Cambridge: Harvard University Press, 1893). Copy in the Harvard University Archives under HUF 715.93.72.