A rare 19th Century brass Belgian twin telescope graphometer, signed Brand Freres Opticiens du Roi Bruxelles, telescope with rack and pinion focusing, dust cap, over graduated bubble level, graphometer with twin sighting vanes, the arc divided 20°-180° and 0°-160°, compass with blued steel needle and cap, over second telescope with rack and pinion focusing, and dust cap, on universal staff mount, on turn mahogany stand - 13in.high