细节
A late 17th/early 18th-Century silver and gilt equinoctial compass sundial,
signed Johann Martin in Augspurg 48, the folding silver hour ring graduated III - XII - IX, with spring-loaded folding gnomon and engraved "hand" pointer, running against the folding silver latitude arc graduated [2°] - 90°, the octagonal gilt baseplate listing the latitudes of Vienna and London, the silver compass rose with an arrow marking magnetic North about 10° West of true North, and a brass-capped, blued-steel needle, the underside with three turned silver feet, the compass base engraved with the names and latitudes of 30 European cities -- 26in. (5.cm) long
See Colour Illustration and Detail
signed Johann Martin in Augspurg 48, the folding silver hour ring graduated III - XII - IX, with spring-loaded folding gnomon and engraved "hand" pointer, running against the folding silver latitude arc graduated [2°] - 90°, the octagonal gilt baseplate listing the latitudes of Vienna and London, the silver compass rose with an arrow marking magnetic North about 10° West of true North, and a brass-capped, blued-steel needle, the underside with three turned silver feet, the compass base engraved with the names and latitudes of 30 European cities -- 26in. (5.cm) long
See Colour Illustration and Detail