An arrowslit (often also referred to as an arrow loop, loophole or loop hole, and sometimes a balistraria) is a narrow vertical aperture in a fortification
A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ( ...
through which an archer
Archery is the art, sport, practice, or skill of using a bow to shoot arrows.Paterson ''Encyclopaedia of Archery'' p. 17 The word comes from the Latin
Latin (, or , ) is a classical language belonging to the Italic languages, Italic ...
can launch arrow
An arrow is a fin-stabilized projectile launched by a bow and arrow, bow. A typical arrow usually consists of a long, stiff, straight ''shaft'' with a weighty (and usually sharp and pointed) ''arrowhead'' attached to the front end, multiple fi ...
s or a crossbowman can launch bolts.
The interior walls behind an arrow loop are often cut away at an oblique angle
In Euclidean geometry
Euclidean geometry is a mathematical system attributed to Alexandrian Greek mathematics , Greek mathematician Euclid, which he described in his textbook on geometry: the ''Euclid's Elements, Elements''. Euclid's method c ...
so that the archer has a wide field of view
The field of view (FoV) is the extent of the observable world that is at any given moment. In the case of s or sensors it is a through which a detector is sensitive to .
Humans and animals
In the context of human and primate vision, th ...
and field of fire
The Field of Fire of a weapon (or group of weapons) is the area around it that can easily and effectively be reached by gunfire. The term ''Field of Fire'' is mostly used in reference to machine guns. Their fields of fire incorporate the beaten zo ...
. Arrow slits come in a remarkable variety. A common and recognizable form is the cross
A cross is a geometrical figure consisting of two intersecting lines or bars, usually perpendicular to each other. The lines usually run vertically and horizontally. A cross of oblique lines, in the shape of the Latin letter X, is also termed a ...
, accommodating the use of both the longbow
A longbow (known as warbow in its time, in contrast to a hunting bow) is a type of tall bow
Bow often refers to:
* Bow and arrow
The bow and arrow is a ranged weapon
A ranged weapon is any weapon
A weapon, arm or armament is any imp ...
and the crossbow
A crossbow is a ranged weapon using an Elasticity (physics), elastic launching device consisting of a bow (archery), bow-like assembly called a ''prod'', mounted horizontally on a main frame called a ''tiller'', which is hand-held in a similar ...
. The narrow vertical aperture permits the archer large degrees of freedom to vary the elevation
The elevation of a geographic
Geography (from Ancient Greek, Greek: , ''geographia'', literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and Solar Sy ...
and direction of his bowshot, but makes it difficult for attackers to harm the archer since there is only a small target at which to aim.
Balistraria, plural balistrariae, from balister, crossbowman can often be found in the curtain walls
Curtain wall may refer to:
* Curtain wall (architecture), the outer skin of a modern building
* Curtain wall (fortification), the outer wall of a castle or defensive wall between two bastions
{{Fortifications
Castle architecture