A bipod is a V-shaped portable attachment that helps support and steady a device, usually a weapon such as a long gun or a mortar. The term comes from the Latin prefix bi- and Greek root pod, meaning "two" and "foot" respectively. Bipods are designed to support the weight of the weapon's front portion and barrel, and provide significant stability against unwanted side-to-side movements (i.e. canting) while allowing free movements pivoting around the transverse axis (pitching). Most modern bipods have foldable and/or telescoping legs, and allow some limited movements around the vertical axis (panning) and even the longitudinal axis (tilting). A bipod by itself, with only two supporting legs, is not completely stable and needs to be reinforced by at least one more point of support to be steady, especially against the horizontal shearing force from recoils. This third point of support is typically the buttstock that is firmly pushed/braced against the shooter's body, but can also be a baseplate (in mortars), sometimes with additional support from a monopod or a bean bag. Firearms On firearms, bipods are commonly used on rifles and machine guns to provide a forward rest and reduce unwanted motion. They are also seen on other long-barreled weapons. Bipods permit operators to easily rest a weapon on objects, like the ground or a wall, reducing their fatigue and increasing accuracy and stability. Bipods can be of fixed or adjustable length. Some can be tilted and also have their tilting point close to the barrel's central axis, allowing the weapon to tilt left and right. Some designs also allow the weapon to be rotated side-to-side. There are three ways for bipods to be folded: away from the shooter, towards the shooter, or into a vertical foregrip. History The first known use of bipods on firearms can be traced back to hand cannons of the 12th century, which were cast iron barrels laid on top of short poles. Bipods on rifles are first known to have been used in an improvised fashion during the mid-19th century, particularly by frontiersmen hunting American bison and other wild animals. For example, the painting "The Long Shot" by Howard Terpning shows native American hunters shooting a rifle with an improvised bipod consisting of two crossed arrows. During the 20th century, use of dedicated bipods increased, and was seen on different types of rifles during wars. For example the Lewis gun (1914) was