Equatorial sundial, known as Ausburg. The original was made by the goldsmith Iohann Georg Vogler (1720-1765) belonging to the fourth generation of a saga of goldsmiths from Ausburg, Germany. It is located in the Naval Museum of Madrid.
The Voglers helped popularize this type of instrument during the 18th century. The "Ausburgs" used to be octagonal clocks that contained a compass with clamping and turning hinges for the hour scale and for the limbo (with the latitude scale). The originals were made using brass and glass.