logo Museo Galileo - Institute and Museum of the History of Science
Quadrato geometrico
Geometrical square

16th cent.
Brass side 16,2 mm, height 22 cm
Florence, Istituto e Museo di Storia della Scienza, inv. 121

The geometrical square was exclusively used for measuring inaccessible distances. It derives from the shadow square usually traced on the back of astrolabes.