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
Classical order while the Corinthian or the Composite order was used for the top story. The Colossal order was invented by architects in the Renaissance. The Colossal order is characterized by columns that extend the height of two or more stories. The Tuscan order has a very plain design, with a plain shaft, and a simple capital, base, and frieze. It is a simplified adaptation of the Doric order by the Greeks. The Tuscan order is characterized by an unfluted shaft and a capital that only consists of an echinus and an abacus. In proportions it is similar to the Doric order,