Detail of the altarpiece of the old chapel of the University that represents Santa Apolonia.From the altarpiece, decorated by Juan de Flandes around 1504, only the paintings of Santa Apolonia and Santa Magdalena made to grisaille, a technique based on a monochrome painting that produces the sensation of being a sculptural relief, are preserved.
Our Urania Propitia was made in the Astonomical compendia style, particularly favoured in the 16th century. In the Urania Propitia we found inside the Renaissance character casing, a folding gnomon sundial, mounted on a compass with a graduated scale from 10 to 30º for correcting magnetic declination.
This instrument is known as the cylindrical dial, the vertical dial, the travelling dial or more commonly, the Shepherd's dial. This particular one is a luxurious version, made for people of social importance, which differs mainly because of its decoration.
Ausburg-made sundials enjoyed great popularity during the 18th century. This one was made by Iohann Georg Vogler who belonged to the fourth generation of a legendary line of goldsmiths in Ausburg, Germany. The original is found in the Naval Museum of Madrid.