Plan of a Four-Bastioned Fort

The image is a black-and-white line drawing showing an architectural top-down view of a symmetrical square fortification. Four pointed bastions extend outward from the corners, with the interior spaces between the bastions filled with a wavy pattern indicative of water or a moat. The plan is labeled with letters 'A', 'B', 'd', 'g', and 'a' to indicate different structural components. The clean, sharp lines define the defensive geometry typical of early modern military architecture.

This diagram belongs to the tradition of 'bastion-fort' design (trace italienne), a shift in military architecture during the 17th century to counter cannon fire. It reflects the rationalization of space and geometry prevalent in early modern natural philosophy and engineering.