Johann Willebrand in Augsburg 德國南方，54 x 57 mm，約 1700
Johann Willebrand in Augspurg, 54 x 57 mm, circa 1700
An equatorial sundial of high quality
Case: silver and brass, partly firegilt, signed, octagonal plate. The geographic latitude of the observation point is set to the quarter-circle on the side. In connection with the magnetic compass the instrument is aligned to the north- south direction. The sun hand projects the position of the sun on the dial engraved with Arabic numbers. One is getting the true local time. On the backside of the ground-plate are engraved the geographical declinations from several European towns.
Johann Willebrand (1658-1726) and Johann Martin are considered to be amongst the best instrument designers and makers of their time. The precision and the craftsmanship they achieved in their constructions remains unrivalled - some of the finest details are only visible with a magnifying glass. Willebrand moved from Frankfurt to Augsburg in 1682 to work with his stepbrother Johann Martin.
Lit.: K. H. Pohl, "Alte Wissenschaften" (Old Sciences), Cologne.