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".
Dio Chrysostom Dio Chrysostom ( ; Greek: Δίων Χρυσόστομος "Dion Chrysostomos"), Dion of Prusa or Dio Cocceianus (c. 40 CE – c. 115 CE), was a Greek orator, writer, philosopher and historian of the Roman Empire in the 1st century. Eighty of his "Discourses" (or "Orations"; Λόγοι ) are extant, as well as a few Letters and a funny mock essay "In Praise of Hair", as well as a few other fragments. His surname "Chrysostom" comes from the Greek "chrysostomos" (χρυσόστομος), which literally means "golden-mouthed". He should not be confused with the Roman historian Cassius Dio, nor with the 4th-century bishop John Chrysostom of Constantinople.