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
Ionic atmosphere a solution. It is the tendency of the applied potential to move the ionic atmosphere itself. This drags the solvent molecules along because of the attractive forces between ions and solvent molecules. As a result, the central ion at the centre of the ionic atmosphere is influenced to move towards the pole opposite its ionic atmosphere. This inclination retards its motion. The model of ionic atmosphere is less adequate for concentrated ionic solutions near saturation. These solutions as well as molten salts or ionic liquids have a structure similar to the crystalline lattice where water molecules are located between ions.