ClipArt ETC
"Hemholtz constructed a series of resonators, each one of which responds powerfully to a single tone of certain pitch or wavelength. they are metallic vessels, nearly spherical, having an opening, as at A, for the admission of the sound waves." -Avery 1895

Hemholtz Resonator

"Hemholtz constructed a series of resonators, each one of which responds powerfully to a single tone…

"...represents a Savart bell and resonator. The length of the resonant air-column is changed by means of the moveable bottom of the resonator, which is to be adjusted by trial for resonant effect." -Avery 1895

Savart Bell and Resonator

"...represents a Savart bell and resonator. The length of the resonant air-column is changed by means…