- A small southern constellation invented by the Frenchman Nicolas Louis de Lacaille during his survey of the southern skies in 1751–52. Pyxis represents a magnetic compass as used by seamen. It is located near the stern of the ship Argo in the same area as the ship’s mast. Lacaille’s original depiction of it was published in 1756 under the French name la Boussole, and in the notes accompanying the chart he described it as ‘le Compas de mer’. On the second edition of his chart in 1763 Lacaille Latinized its name to Pixis Nautica (sic), which was subsequently shortened, with amended spelling, to just Pyxis.