The quintant has a polished brass Lorieux-Borda pattern frame, with a wooden handle. The double-ended tangent screw is positioned on the front of the index arm and the clamping screw is on the back. The instrument has four shades, one orange, two red, and one green, and three horizon shades, two red and one green. Index- and horizon-glass adjustment is made by square-headed screws and a detached key.

Attached to the quintant is a magnifier on a 100mm hinged, swivelling arm with a frosted glass shade that is now missing. There is also a threaded telescope bracket with perpendicular adjustment. It is made by a rising-piece and a milled knob. The telescope is 132 mm in length with an erect image. The box, the adjusting key and various unidentified parts are missing.

The instrument has a polished brass limb with an inlaid silver scale from -5° to 170° by 10 arcminutes, measuring to 142°. The quintant has a silver vernier measuring to 10 arcseconds, with zero at the right.

Augustin Santi was a scientific instrument maker in Marseilles from 1830-84.