18th century map of the Zodiac sign Sagittarius

The constellation Sagittarius, engraved by Johann Christoph Berndt for the celestial atlas 'Mercurii Philosphici Firmamentum Firmianum', named for Thomas's patron, Leopold Anton von Firmian, Archbishop of Salzburg.

Corbinianus Thomas (1694-1767), a Benedictine monk, was Professor of Mathematics and Theology at the University of Salzburg. His star atlas was first published in 1730 at Frankfurt, with a second edition at Augsburg the following year. He used an odd system for nomenclature: Greek letter for the star, Roman numeral for the magnitude and Arabic numeral for the star catalogue reference. Individual zodiac signs of this period are uncommon, especially in original colour.