Doric order The Roman architect Vitruvius, following contemporary practice, outlined in his treatise the procedure for laying out constructions based on a module, which he took to be one half a column's diameter, taken at the base. An illustration of Andrea Palladio's Doric order, as it was laid out, with modules identified, by Isaac Ware, in "The Four Books of Palladio's Architecture" (London, 1738) is illustrated at Vitruvian module. According to Vitruvius the height of Doric columns is six or seven times the diameter at the base. This gives the Doric columns a shorter, thicker look than Ionic columns, which have 8:1
Colosseum podium on which stands a tall attic, both of which are pierced by windows interspersed at regular intervals. The arcades are framed by half-columns of the Doric, Ionic, and Corinthian orders, while the attic is decorated with Corinthian pilasters. Each of the arches in the second- and third-floor arcades framed statues, probably honoring divinities and other figures from Classical mythology. Two hundred and forty mast corbels were positioned around the top of the attic. They originally supported a retractable awning, known as the "velarium", that kept the sun and rain off spectators. This consisted of a canvas-covered, net-like structure made