What roman author described the technique of Opus quadratum?
Vitruvius Marcus Vitruvius Pollio (born c. 80–70 BC, died after c. 15 BC), commonly known as Vitruvius, was a Roman author, architect, civil engineer and military engineer during the 1st century BC, known for his multi-volume work entitled "De architectura". His discussion of perfect proportion in architecture and the human body, led to the famous Renaissance drawing by Da Vinci of "Vitruvian Man".
Ausonius Decimus "or" Decimius Magnus Ausonius ( ; c. 310 – c. 395) was a Roman poet and teacher of rhetoric from Burdigala in Aquitaine, modern Bordeaux, France. For a time he was tutor to the future emperor Gratian, who afterwards bestowed the consulship on him. His best-known poems are "Mosella", a description of the river Moselle, and "Ephemeris", an account of a typical day in his life. His many other verses show his concern for his family, friends, teachers, and circle of well-to-do acquaintances and his delight in the technical handling of meter.