The Defensive Armour and the Weapons and Engines of War of Mediæval Times, and of the "Renaissance."

by R. Coltman Clephan

CALTROP, OR CROW’S FOOT.

This, the Roman murex or tribulus, was a sharp point of iron standing upright, fashioned like a crow’s foot. They were strewn broadcast on the ground, for the purpose of maiming horses in a charge of cavalry, or placed on a moat filled up with fascines, or on a breach to resist an attempt at escalade. Knightly spurs have been known to have been used for this purpose. The name is an abbreviation for cheval-trap. There are some specimens in the Rotunda, Woolwich, varying in height from 1.25 to 2.5 inches.[30]