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
Basilica of San Bernardino in three different architectural orders: the first in doric order, the second ionic and the third corinthian. On the trabeation of the first order there are illustrated metops, on the second order there is a refined triple lancet window, which was added during the restoration work in the 18th century, and on the third order there are three big oculuses. Four sequences of double columns vertically divide the church, establishing a suggestive and harmonic diagram of nine squares on three lines. The principal gate is embedded by spiral columns. The lunette includes a Silvestro dell'Aquila's high relief illustrating "Madonna with