This elegant device demonstrates the repulsion of like charges and the attraction of unlike charges. It was described by several authors, most notably George Adams in An Essay on Electricity. The apparatus was long used as a "toy" in recreational physics. A similar contrivance was depicted in 1780 by Filippo Lucci on the ceiling of the Stanzino delle Matematiche at the Uffizi Gallery.

A round mahogany base carries a set of pillars holding brass cross-bars and cords from which nickel-plated brass bells are suspended.

When the instrument is connected to an electrostatic machine via the central brass rod terminating in a sphere, the clappers begin to oscillate, causing the bells to ring.