Pedro Nuñez and the first printed treatise on twilight observation



Pedro Nuñez (the name is also written variously as Nunes, Nonius, Nonnius, and Nunnius) was born at Alcacer do Sol, Portugal, in 1502, and died in 1578. In that period and in that country, it was inevitable that his interests were in cosmography and navigation. His principal claim to fame is as author of the major treatise De Arte Atque Ratione Navigandi, which was published in 1546.