Paul Garcia, age 16, of Fargo, N.D., for his question:
HOW DID THE CATAPULT WORK?
A catapult was the artillery of ancient warfare. Some could throw a stone weighing 60 pounds with enough force to knock down a battlement or even sink a ship. Some of the catapults had a range of at least a quarter of a mile.
Power for the catapult weapons usually came from a twisted skein of hair or sinew. Inserted in this skein was an arm made of wood or of horn, wood and sinew glued together and bound with leather. At the end of the arm was a sling.
To shoot the stone, the arm was wound down, twisting the skein tighter. Then it was released, shooting the missile from the sling.
Great quantities of hair were needed for catapult weapons. When the Romans besieged Carthage in 146 B.C., all the Carthaginian women cut off their hair to supply the catapults.
The actual secret of making the skein and the arm is not known today. Models have been made with a skein of twisted rope and an arm of timber, but such modern models have not been able to fire a stone weighing more than eight pounds.
The catapult was a heavy throwing machine mounted on a wooden base. The catapults threw darts or arrows. The ballista was a heavy crossbow which threw stones or similar missiles.
It is hard to estimate the exact range and power of these ancient weapons. One catapults, a foot long, supposedly could throw its arrows half a mile. Ballistas discharged heavy wooden beams and stones weighing close to 400 pounds.
Catapults were not known to the Greeks until 397 B.C. The Greek engineer Archimedes perfected the weapon at Syracuse. He made one catapult that threw a 100 pound stone to destroy a great wooden tower of the Romans.
When the Romans laid siege to Jerusalem in A.D. 70, they used a huge ballista that shot stones. It is said that the stones whistled like modern shells from a cannon.
In the Middle Ages, the secret of making catapults of the ancient type was already lost. A machine was used that had a weight at one end of an arm. When a catch was released, the weighted end dropped and the other end shop up in the air. These machines could toss a 300 pound missile, but could not send it fast or far.
These catapults were used principally in sieges. Sometimes, history tell us, when a herald came out to offer peace, the besiegers catapulted him back into the town.
Some of the smaller catapults were really large crossbows mounted on bases. Others, instead of getting power from a bent bow, got it from two rigid bars that passed through an upright, twisted skein.
During World War I, small catapults were used to hurl bombs and gas shells.
Naval vessels and some merchant ships carry catapults to launch airplanes from their decks. Foreign mail has been speeded up by launching mail planes from ships 500 to 600 miles from their destinations.