A 17th-Century Base Meant to be Used for a Sundial
Fantastic original antique copperplate engraving showing a base for a sundial. The engraving was produced by Franz Ritter in a treatise on sundials, which include the famous and incredibly bizarre "gnomonic" world projection, that is, a mathematically precise projection as if it were projected on a sundial.
By positioning a vertical object at the top end of the engraving, observing the location of the shadow at a certain time would allow for the time to be told. The Roman and Arabic numbers surrounding the map give the hour of the day. A number of additional lines emanate and divide the space into five-degree increments.
The map includes a number of decorative elements, including a compass at the bottom. The other decorative elements are distinctly baroque.
Ritter was a German mathematician, cartographer, and astronomer, active in in the first part of the 17th century.
Ritter's most noteworthy accomplishment was his development of an unusual gnomic projection and his so-called “sundial” world map.
A native of Nuremberg, He had studied under Johann Praetorius at the University of Altdorf. Ritter specialized in the design and manufacture of astrolabes, sundials, and other astronomical, horological and cartographical instruments.