Bow and arrow
The bow and arrow is a projectile weapon system (a bow with arrows) that predates recorded history and is common to most cultures. Archery is the art, practice, or skill of applying it.
Description
A bow is a flexible arc which shoots aerodynamic projectiles (arrows or quarrels, sometimes stones) by means of elastic energy. Essentially, the bow is a form of spring powered by a string or cord. As this string is drawn, energy is stored in the flexible limbs of the bow; the energy is transferred to the arrow when the string is released, projecting it much farther than a weapon could be thrown. Today, bows and arrows are used primarily for hunting and for sport (see archery). Though they are still occasionally used as weapons of war, the development of gunpowder and muskets, and the growing size of armies, led to their replacement in warfare several centuries ago in much of the world.
Someone who makes bows is known as a bowyer, and one who makes arrows is a fletcher—or in the case of the manufacture of metal arrow heads, an arrowsmith.
History
The bow and arrow was not the first composite projectile weapon to be invented. It was preceded by the sling and by spear throwers such as the atlatl of the Americas and the woomera of Australia. A number of cultures in historical times lacked the bow and arrow, and in others oral history records a time before its acquisition.
The earliest potential arrow heads date from about 64,000 years ago in the South African Sibudu Cave.[1][2] By 16,000 BCE flint points were being bound by sinews to split shafts. Fletching was being practiced, with feathers glued and bound to shafts.
The first actual bow fragments are the Stellmoor bows from northern Germany.[3] They were dated to about 8,000 BCE but were destroyed in Hamburg during the Second World War. They were destroyed before carbon 14 dating was invented and their age is attributed by archaeological association. The oldest bow in one piece, are the elm Holmegaard bows from Denmark which were dated to 9,000 BCE. High performance wooden bows are currently made following the Holmegaard design.
Around 3,300 BCE "Ötzi the Iceman" was shot through the lung near the present-day border between Austria and Italy and was mummified. Among his preserved possessions were bone and flint tipped arrows and an unfinished yew longbow 1.82 m (72 in) tall.[4] His arrows had spiral feathers, which spun the arrow in flight and tend to give a straight flight despite any small asymmetry.
Bow construction
The basic elements of a bow are a pair of curved elastic limbs, traditionally made from wood, connected by a string. By pulling the string backwards the archer exerts compressive force on the string-facing section, or belly, of the limbs as well as placing the outer section, or back, under tension. While the string is held, this stores the energy later released in putting the arrow to flight. The force required to hold the string stationary at full draw is often used to express the power of a bow, and is known as its draw weight. Other things being equal, a higher draw weight means a more powerful bow, which is able to project arrows heavier, faster, or a greater distance.
In bows drawn and held by hand, the maximum draw weight is determined by the strength of the archer. The maximum distance the string could be displaced and thus the longest arrow that could be loosed from it, a bow’s draw length, is determined by the size of the archer. For bows drawn and held mechanically, the maximum draw weight was a matter of engineering. The mechanical force required to draw the string was mainly limited by the time required to do so.
Limbs
The elastic qualities of the limbs of a bow provide a wide variety of performance characteristics. Longer limbs typically provide longer draw lengths, but the archer may have other constraints that limit the possible size of the bow; a mounted archer usually prefers something smaller than the head-high weapon typically employed by his infantry counterpart.
The limbs of the bow must endure repeated bending into a deep curve. The tips of the limbs may consist of a single curve for the longbow, or be bent back upon themselves in the recurve bow. The recurve allows for greater draw weight with shorter limbs, but this places greater strain on the limb materials and may increase string noise when shot. Decurve bows, where the tips bend towards the archer, provide proportionally lower draw weights but may be made with relatively poor materials.
The considerable strain placed upon the limbs of the bow when drawn requires durable materials with high tensile strength and extensibility on the back of the bow, and high compressive strength and compressibility on the belly. Wood is readily obtained, reasonably good for both back and belly, and easily shaped; self bows consisting of a single material are usually of wooden construction. Considerable compromise must be made in selecting a single material, and sophisticated techniques were employed to overcome this problem. The flatbow's cross section is shaped to spread stress more evenly, and the yew for use in English longbows was oriented to take advantage of the ability of the heartwood to store energy in compression, and the outer sapwood's strength in tension.
A composite bow uses a combination of materials to create the limbs, allowing the use of materials specialized for the different functions of a bow limb. The classic composite bow uses wood for lightness and dimensional stability in the core, horn to store energy in compression, and sinew for its ability to store energy in tension. Such bows, typically Asian, would often use a stiff end on the limb end, having the effect of a recurve. In this type of bow, this is known by the Arabic name 'siyah'.[5] While composite limbs allow greater draw length with shorter limbs, they are typically less robust than a wooden limb. Composite bows are made with water-soluble glue and could be damaged by exposure to moisture.
Modern construction materials for bows include laminated wood, fiberglass, metals, and carbon fiber components.
String
The string that connects the tips of the limbs is under considerable stress when drawn. A rule of thumb is that a string should withstand a static tension at least four times the draw weight of its bow, because of the substantial shock forces on release and when pulled taut. An ideal string material is strong for its mass, resists stretching, and remains strong after exposure to moisture. To enhance accuracy, the nocking point for the arrow will be marked, often by the addition of some turns of waxed thread, or a small metallic ring.
Historically bow strings were frequently made from animal byproducts such as sinew, intestine (catgut), or hair. Plant fibers such as linen or hemp were also common and usually had a superior ratio of strength to mass. When treated with beeswax they are very resistant to moisture.
Modern synthetic polymers are totally resistant to moisture, have excellent mechanical properties, and are very cheap to produce. Modern compound bows have a mechanical system of pulley cams over which cables wind, before ending in a 'tail' to which the actual string is attached.
Crossbows
In a crossbow, the limbs of the bow, called a prod, are attached to a crosspiece or stock in order to allow for mechanical pulling and holding of the string. This allows for a much larger draw weight than could be drawn and held by hand. A crossbow can be much smaller than a manually held bow of the same power, or may be constructed on a much larger scale like the arbalest and ballista for use as a siege engine.
The drawing of the bow could be accomplished through use of a lever, the archer's legs, or complex windlass designs. The principal disadvantage to a crossbow is the time taken for reloading. While repeating crossbows existed, as did crossbows which shot more than one arrow (or 'bolt') at a time, for the most part an archer could deliver many times more arrows per minute than a crossbowman could. The weapon's additional weight and the greater potential for mechanical failure could also be a problem for armed forces on the move.
Crossbows require less training and practice than traditional bows, which allowed cheaper and faster raising of troops. Crossbows are also more accurate than hand bows, allowing shooting individual targets rather than volleys. As time progressed, more powerful crossbows were developed. A crossbow bolt, being considerably heavier than its bow counterpart, was likely to give a more devastating wound, even through heavy armour.[6]
See also
References
- ^ "Stone-Age arrows found", News, University of Johannesburg. See also Antiquity 84:635-648
- ^ Lucinda Backwell, Francesco d'Errico and Lyn Wadley (june 2008). "Middle Stone Age bone tools from the Howiesons Poort layers, Sibudu Cave, South Africa". ScienceDirect.
{{cite news}}: Check date values in:|date=(help) - ^ Collins, Desmond (1973). Background to archaeology: Britain in its European setting (Revised ed.). Cambridge University Press. ISBN 0-521-20155-1.
- ^ Norman Davies (1996), Europe: A History, Oxford: Oxford University Press, ISBN 0-19-820171-0.
- ^ R P Elmer, Target Archery
- ^ Papal Bull 1139
Further reading
- The Traditional Bowyers Bible Volume 1. 1992 The Lyons Press. ISBN 1-58574-085-3
- The Traditional Bowyers Bible Volume 2. 1992 The Lyons Press. ISBN 1-58574-086-1
- The Traditional Bowyers Bible Volume 3. 1994 The Lyons Press. ISBN 1-58574-087-X
- The Traditional Bowyers Bible Volume 4. 2008 The Lyons Press. ISBN 978-0-9645741-6-8
- U. Stodiek/H. Paulsen, "Mit dem Pfeil, dem Bogen..." Techniken der steinzeitlichen Jagd. (Oldenburg 1996).
- Gray, David, "Bows of the World". The Lyons Press, 2002. ISBN 1-58574-478-6.
- Comstock, Paul. "The Bent Stick"
External links
