An early 19th Century "Butterfield"-type brass octagonal brass equinoctial dial signed N.BION A PARIS with folding bird gnomon, calcutated for latitudes 40°, 45°, 50° and 55°, the compass with fine blued-iron needle, with four levelling screws, the underside engraved with the latitudes of twenty-four continental cities and towns - 3in.(7.6cm)long