Caltrop, reputedly used at the Taku Forts, 2nd China War (1856-1860), 1860 (c)

Iron, four pronged caltrop, 1860 (c).

The caltrop, also known as a 'crow's foot', was a simple and cost effective defensive device placed on a battlefield in order to disrupt enemy formations. They were particularly effective against cavalry as horses could be quickly disabled if a spike penetrated their hooves. A piece of ground covered with crow's feet acted like a modern minefield. The basic design which always leaves a spike protruding upwards differs little from another caltrop in the National Army Museum Collection believed to have been made in the sixteenth century.