Wubei Zhi (Vol. 48)

This page contains three technical illustrations of defensive military equipment, specifically caltrops and a spiked frame. At the top is a square frame labeled "Yang Ti" (Raised Hoof). The frame is lined with sharp, triangular spikes pointing both outward and inward. On the right side of the frame, there is a handle or attachment mechanism. In the lower left, there is a large three-pointed caltrop labeled "Mu Ling Jiao" (Wooden Caltrop). It consists of a central hub with three detachable or socketed triangular spikes. In the lower right, there are two variations of a four-pointed caltrop labeled "Tie Ling Jiao" (Iron Caltrop). These are depicted as thin, sharp metal spikes joined at a center, designed so that one point always faces upward when thrown on the ground.