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The polybolos (the name means "multi-thrower" in
Episode 152: Arrow Machine Gun
mythresults.com, November 3, 2010.
The Repeating Catapult of Dionysius
(clip) {{Ancient mechanical artillery and hand-held missile weapons Ancient Greek artillery Projectile weapons Lost inventions
The polybolos (the name means "multi-thrower" in Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
) was an ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
repeating ballista
The ballista (Latin, from Ancient Greek, Greek βαλλίστρα ''ballistra'' and that from βάλλω ''ballō'', "throw"), plural ballistae or ballistas, sometimes called bolt thrower, was an Classical antiquity, ancient missile weapon tha ...
, reputedly invented by Dionysius of Alexandria (a 3rd-century BC Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
engineer at the Rhodes
Rhodes (; ) is the largest of the Dodecanese islands of Greece and is their historical capital; it is the List of islands in the Mediterranean#By area, ninth largest island in the Mediterranean Sea. Administratively, the island forms a separ ...
arsenal,) and used in antiquity. The polybolos was not a crossbow
A crossbow is a ranged weapon using an Elasticity (physics), elastic launching device consisting of a Bow and arrow, bow-like assembly called a ''prod'', mounted horizontally on a main frame called a ''tiller'', which is hand-held in a similar f ...
since it used a torsion mechanism, drawing its power from twisted sinew-bundles. However the earlier and similar oxybeles employed a tension crosbow mechanism, before it was abandoned in favor of torsion.
Philo of Byzantium
Philo of Byzantium (, ''Phílōn ho Byzántios'', ), also known as Philo Mechanicus (Latin for "Philo the Engineer"), was a Greek engineer, physicist and writer on mechanics, who lived during the latter half of the 3rd century BC. Although he wa ...
( 280 BC – 220 BC) encountered and described a weapon similar to the polybolos, a catapult
A catapult is a ballistics, ballistic device used to launch a projectile at a great distance without the aid of gunpowder or other propellants – particularly various types of ancient and medieval siege engines. A catapult uses the sudden rel ...
that could fire again and again without a need for manual reloading. Philo left a detailed description of the gear
A gear or gearwheel is a rotating machine part typically used to transmit rotational motion and/or torque by means of a series of teeth that engage with compatible teeth of another gear or other part. The teeth can be integral saliences or ...
s that powered its chain drive
Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles. It is also used in a wide variety of machines besides vehicles.
...
(the oldest known application of such a mechanism) and that placed bolt after bolt into its firing slot.
Design
The polybolos would have differed from an ordinary ballista in that it had a wooden hopper magazine, capable of holding several dozen bolts, that was positioned over the mensa (the cradle that holds the bolt prior to firing). The mechanism is unique in that it is driven by a flat-link chain connected to awindlass
The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound arou ...
. The mensa itself was a sliding plank (similar to that on the gastraphetes) containing the claw latches used to pull back the drawstring and was attached to the chain link. When loading a new bolt and spanning the drawstring, the windlass is rotated counterclockwise by an operator standing on the left side of the weapon; this drives the mensa forward towards the bow string. At the very front, a metal lug triggers the latching claws into catching the drawstring.
Once the string is held firm by the trigger mechanism, the windlass is then rotated clockwise; pulling the mensa back and drawing the bow string with it. At the same time, a round wooden pole in the bottom of the magazine is rotated via a spiral groove being driven by a rivet attached to the sliding mensa; dropping a single bolt from a carved notch in the rotating pole. With the drawstring pulled back and a bolt loaded on the mensa, the polybolos is ready to be fired. As the windlass is rotated further back to the very back end, the claws on the mensa meets another lug like the one that pushed the claws into catching the string. This one causes the claws to disengage the drawstring and automatically fires the loaded bolt. Upon the bolt being fired, the process is repeated. The repetition provides the weapon's name, in Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
, "throwing many missiles", from (), "multiple, many" and () "thrower", in turn from (), "to throw, to hurl", literally a multithrower.
Popular culture
In 2010, a ''MythBusters'' episode was dedicated to building and testing a replica, and concluded that its existence as a historical weapon was plausible. However, the machine MythBusters built was prone to breakdowns that had to be fixed multiple times.mythresults.com, November 3, 2010.
See also
* Gastraphetes * Repeating crossbow * Rapid fire crossbow * Chain gun * PanjaganReferences
Bibliography
*Duncan B. Campbell and Brian Delf, ''Greek and Roman Artillery 399 BC–AD 363'', New Vanguard series 89, Osprey Publishing Ltd., Oxford 2003. *Joseph Needham, '' Science and Civilization in China: Volume 5, Chemistry and Chemical Technology; Part 6, Military Technology: Missiles and Sieges'', Cambridge University Press, Cambridge 1995. , 052132727XExternal links
The Repeating Catapult of Dionysius
(clip) {{Ancient mechanical artillery and hand-held missile weapons Ancient Greek artillery Projectile weapons Lost inventions