Invented by Benjamin Franklin (1706-1790), it is known as the electric carillon. The one presented here is composed of three brass bells (diameters 5.3 cm) aligned at the same height (15 cm) with respect to the rectangular wooden base (24 x 13 cm), on which are set the staffs supporting them. Of these, the one in the centre is made of glass and those on the sides are brass.
Above the bells there are three thin brass rods of the same length (17 cm). The central one is straight while the ones on the sides are curved at the top and end with a hook, from which a small metal ball (diameter 0.6) is suspended. One of the balls is attached to a cotton thread and the other to a wire; the balls hang at the same height as the bells between the central staff and the two at the sides.
On attaching the central bell to one of the two poles of an electrostatic generator by means of the staff the balls are charged by induction and are attracted by the central bell which, on being struck, emits a characteristic sound. ...continues