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
Giacomo Barozzi da Vignola company with Baldassare Peruzzi, Giulio Romano, Andrea Palladio and others furnished material for an exhibition in 2001 His two published books helped formulate the canon of classical architectural style. The earliest, "Regola delli cinque ordini d'architettura" ["Canon of the five orders of architecture"] (first published in 1562, probably in Rome), presented Vignola's practical system for constructing columns in the five classical orders (Tuscan, Doric, Ionic, Corinthian and Composite) utilising proportions which Vignola derived from his own measurements of classical Roman monuments. The clarity and ease of use of Vignola's treatise caused it to become in succeeding centuries the most published