FunctionTo visualize two-dimensional vibration patterns. To create the patterns, one would have held the plate between two fingers at one of the vibration nodes, and with a fiddle bow would have struck the plate until the pattern emerged. It takes a good amount of practice to make this happen. Depending on which node and where you strike the plate, different patterns emerge. The nodes and antinodes from the vibrations are felt by the fine salt sprinkled on the plate, thus creating the visible patterns (the same way iron filings shows magnetic lines).

Koenig specially designed this handheld plate to be used with the fixed plate found on the tripod (1997-1-1060a). Holding the handheld plate so the handle is above the plate, one would create a vibration pattern using the technique already explained. Then this handheld plate would be moved over the fixed plate. The vibration from the handheld plate would be felt by the fixed one, thereby generating the same pattern on the fixed plate without having to strike it with a bow.

Several examples of Chladni plates can be seen on YouTube and elsewhere. See, for instance, the one from the Harvey Mudd College. In addition, a demonstration of a set of Chladni plates was produced for the Fondazione Scienza e Tecnica, Florence by Paolo Brenni and can be watched here.

Primary SourcesRudolph Koenig, Catalogue des appareils d'acoustique construits par Rudolph Koenig (Paris, 1889), 57, no. 161.

Related WorksDavid Pantalony, Rudolph Koening (1832-1901), Hermann von Helmholtz (1821-1894) and the Birth of Modern Acoutsics, unpublished dissertation, University of Toronto, 2002.

David Pantalony, "Rudolph Koenig's Workshop of Sound: Instruments, Theories, and the Debate over Combination Tones," Annals of Science 62 (2005): 57-82.

Thomas Greenslade, "The Acoustical Apparatus of Rudolph Koenig," The Physics Teacher, 30 (December, 1992).