Fourier analyzer

From Ccpi

The Fourier analyzer, which was called by Rudolph Koenig an Analyzer of the timbre of sounds, is a large device for qualitatively comparing the Fourier components of a sound. Fourteen large Helmholtz resonators of varying sizes are connected via rubber tubing to individual manometric flames, which are reflected in a hand-driven rotating mirror for viewing. The resonators are individually adjusted to produce a fundamental tone and its harmonics for analysis. The taller a flame is, the larger its corresponding Fourier component. The manometric flames are stabilized with mica strips, which protect against unwanted wind and air currents.