What is a crossbow?
A crossbow is a variation on the general bow design. Instead of the limbs being held vertically, they are mounted horizontally on a stock much like that of a rifle.
The limb design can either be Compound or a Recurve with several different stock Design features, but the basic concept of firing is the same. The string is pulled back locked into place.
The string remains in this locked position, held soley through mechanical means until the energy stored in its limbs is released by a trigger mechanism, which launches the bolt or arrow.
Why the invention of the crossbow?
Crossbows could be kept cocked and ready to shoot for some time with little effort, allowing crossbowmen to aim better, of the time crossbows had crude sights and at the same time the first sighting systems were created to compensate trajectories.
The disadvantage of a crossbow is the greater weight and clumsiness compared to a bow, as well as the slower rate of fire and the lower efficiency of the acceleration system.
Crossbow draw weights are generally higher than a hand-held bow.
Crossbows have a much shorter draw length than bows. This means that for the same energy to be imparted to the arrow (or bolt) the crossbow has to have a much higher Draw Weight and will usually require some kind of cocking apperatus to overcome the extra resistance of much stronger bow limbs.
What is the difference between a crossbow bolt and a crossbow arrow?
Some of the arrow-like projectiles of a crossbow are called bolts. These are much shorter than arrows, but will be several times heavier.
In ancient times the bolts of a strong crossbow were usually several times heavier than arrows. Bolts typically have three fletches, commonly seen on arrows and can be fitted with a variety of heads, some even had sickle-shaped heads to cut rope.
Crossbows could be adapted as well to shoot stones, in which case they are called stone-bows and primarily used for hunting wildfowl, these usually have a double string with a pouch between the strings to hold the stone.
