There is a little instrument used in war called a caltrop, named
from a kind of thistle. It consists of a small bar of iron, with
several sharp points projecting from it one or two inches each
way. If these instruments are thrown upon the ground at random,
one of the points must necessarily be upward, and the horses
that tread upon them are lamed and disabled at once. History
tells that Darius caused caltrops to be scattered in the grass
and along the roads, wherever the army of Alexander would be
likely to approach his troops on the field of battle.
(1406)
=Hidden, The, Exposed=--See DETECTION.