This device was designed and built in the laboratory and instrument shop of the Physics Dept. of the Case School of Applied Sciences. It is built from Lord Kelvin’s harmonic synthesizer design of 1873. This may be the world’s first additive synthesizer. More information about the project is here:
Physics Dept. of the Case School of Applied Sciences
The Harmonic Synthesizer was used was used by Dayton Miller to check the results produced by the harmonic analyzer against the original phonodeik curves.
The phonodeik is an instrument designed by Dayton Miller. It allows one to photographically record the shape of complex sound waves more precisely than previously possible.
This all started with Lord Kelvin inventing an analog computer to predict tides.