Mésure et proportion dans la Loge de la Signoria à Florence

The Loggia of Priori represents one of the earliest examples of a political loggia. The project, in plan and elevation, was conceived on a series of grids which on the various scales help the planner to redistribute the quantities at the moment of the definition of the model
details. The hypothesis explained here considers the existence of diagrams in plan (icnographia) and elevation (orthographia) which were obtained through arithmetical-geometrical reasoning combined with Inventio (according to Vitruve) and which gave the
possibility of communicating, on the various scales, metric form and quantities through the drawings. The metric analysis of the Loggia of Priori highlighted the employment of the canna mercantile di 4 braccia as the measuring instrument for the dimensioning of the general outline of the project. The scale of the model, in this specific case, was obtained rationing the canna mercantile (4 florentines braccia = 2,3344 m) with the
under multiples of the Florentine braccio (0,5836 m). This method allows, through a simple and easily comprehensible diagram, to communicate the shape and the general measures of the architectural object.