Little is known about Corbinianus Thomas, a Benedictine monk at Salzburg, but his Firmamentum is one of the unsung treasures of celestial cartography. It contained 54 small charts of individual constellations. Thomas used an interesting nomenclature system: Bayer Greek letter, Roman numeral for magnitude, and Arabic numeral for reference to a star catalog. This system originated on the large globes of Coronelli, as did many of Thomas's figures.

This lot includes two striking views of constellations. The first sheet shows Sagitta (or the Arrow) and Aquila (or the Eagle). The second engraving depicts the former constellation Lilium (a fleur-de-lis that is now part of Aries) and Triangulum.

References: Kanas (2nd ed.) pp. 207-8; Warner, p. 251.

Condition: B+

Both sheets have a light damp stain at bottom right that barely enters into the map image. The second sheet is on watermarked paper and has minor show-through of colorist's ink on verso.