(Lat. modulus, a measure), in architecture, the semidiameter of the column at its base; the term was first set forth by Vitruvius (iv. 3), and was generally employed by the architects of the Italian revival to determine the relative proportions of the various parts of a columnar ordinance. The module was divided by the revivalists into thirty parts, called minutes, allowing of much greater accuracy than was thought necessary by Vitruvius, whose subdivision was usually six parts. The tendency now is to adopt the whole diameter instead of the semi-diameter when determining the height of the column or entablature or any of their subdivisions. The term module is also applied in hydraulics to a contrivance for regulating the supply of water from an irrigation channel.