Caelum /ˈsiːləm/ is a faint constellation in the southern sky, introduced in the 1750s by Nicolas Louis de Lacaille and counted among the 88 modern constellations. Its name means "chisel" in Latin, and it was formerly known as Caelum Scalptorium ("the engravers' chisel"); a rare word, unconnected with the far more common Latin caelum, meaning "sky, heaven, atmosphere". It is the eighth-smallest constellation, and subtends a solid angle of around 0.038 steradians, just less than that of Corona Australis.