This galvanometer, much older than the date of its purchase, was part of a collection of instruments belonging to Professor Gian Pietro Radicati (professor of experimental physics in Cagliari from 1853 to 1871) and acquired by the Physics Laboratory following his death.
It is an astatic galvanometer, in which the pin of the astatic system is horizontal and passes between, but without touching, the ivory blocks on the rectangular frames of the two vertical coils in series, inside of which one of the needles of the astatic element is free to rotate.
The coils and the suspending rod are attached, by means of brass brackets, to a thick, vertical copper plate covering the entire face of the wooden case of the instrument (supporting base 13 x 9 cm, height 20 cm).
A card is glued to the front of the copper plate: it bears a semicircular scale with zero at the centre, divided into degrees from 0 to 90 on both sides of the zero on one end of which the second needle, which also acts as the index, moves. Oscillations are quickly dampened by induction by the copper plate.
A pane of glass closes the front of the instrument.