On Military Matters

This woodcut illustration shows a mechanical device designed for erecting a bridge. The machine is built on a large wooden platform. This platform is supported by several rollers or small wheels to make it mobile. On the left side of the platform, a multi-sectioned wooden ramp or bridge is shown in a partially raised position. Ropes hold this structure in place. In the center of the platform, a vertical wooden frame houses a capstan, also known as a windlass. This capstan has two horizontal bars. These bars are used to wind the ropes that control the movement and elevation of the bridge.

Device for extending a bridge.

This woodcut illustration shows a device for extending a bridge while in operation. Two soldiers wear armor typical of the late 1400s. One soldier sits on the wheeled platform on the right side. He is pulling a thick rope that is wound around the central capstan. The second soldier stands to the left. He operates a vertical mechanism near a tall wooden frame. This frame is topped with a protective triangular wooden roof. The entire device is positioned at the edge of a body of water. This is indicated by stylized wave lines on the far left. The image suggests the bridge is being extended across a river or a moat during a military operation.