Brass Graphometer Signed "canivet At La Sphère In Paris 1772"

Brass graphometer signed "Canivet à la Sphère à Paris 1772".
It features an openwork brass semi-circle with two scales from 0 to 180 degrees, as well as two sights, and a central compass with a silvered bottom engraved with a 4-direction compass rose and four additional directions.
In the center of the compass, a steel pivot supports a partially blued steel needle with a brass pivot that locks with a screw system. All around the compass rose are degree graduations from 0 to 90 repeated four times, topped by a glass.
A movable arm, decorated with two small acanthus leaves, is attached to the main plate below the compass and features two sights.
The main plate is fixed on a ball-and-socket joint set into its support tube with its butterfly screw.
Original wooden case covered in brown leather with fleur-de-lis decoration, inside lined with green fabric.
Dimensions (graphometer): length 24.3 cm x height 12.7 cm.
Paris dated 1772.