The beauty of measure. Control, drawing, design in Milan in Bramante’s and Leonardo’s work. / La bellezza della misura. Controllo, disegno, progetto a Milano da Bramante a Leonardo.

Measurement, intended as a quantitative evaluation tool, has always been a significant instrument of investigation and knowledge. In architecture, it refers to the survey, considered the most powerful tool for investigating the project and the building’s dimensioning. Measure defines and characterizes the artificial space by expressing dimensions through numbers and controlling the construction. In Classical architecture, measurement used to mean proportion and the design is a numerical program that defines the parts in the whole, where the number is linked to the unit of the metric system in use. Late 15th-century Milan architecture offers two exemplary masterpieces of how numbers and measurements characterize design in creating spaces, which can generate a visual space that expands the physical reality of construction. These are the two experimental interpretations of perspective on an architectural scale, adopted by Bramante and Leonardo in the church of Santa Maria presso San Satiro and in the refectory of Santa Maria delle Grazie, revealing a design program in which the geometry of space (number and measure) is the key to the artifice generating a virtual space that differs from the real one in a sort of analogical anticipation of augmented reality. Perspective, meaning the measure of space, creates virtual interiors where the harmony of numbers that define the concept controls becomes concinnitas.