Catapulting maths to a new height
People who made ancient catapults combined mathematics and engineering skills to create the most powerful weapons of their time, according to a new report.
The catapult makers also met colleagues in neighbouring countries to discuss their designs in the ancient equivalent of a scientific conference.
Cuomo described how catapults were made as early as the 9th century BC to be used during war to launch arrows or stones at the enemy and their forts. Sophisticated catapults propelled stones as heavy as 80 kilograms into the air.
"Until the invention of gunpowder, the catapult was the most powerful weapon," she said. An army could use a single catapult for up to 20 years.
The early Greek catapult was the 'belly bow' and, as its name suggests, consisted of a bow that rested on a person's belly. Catapult shooting was one of the traditional Greek sports used to train the military.
After the belly bow came larger, stronger catapults that allowed bigger projectiles to be launched. These were made from an enlarged bow, placed on a stand, with winches used to pull back the arm and launch the projectile.
The torsion catapult was a more sophisticated design. It was powered by springs made from tightly wound rope or animal sinew, said Cuomo. When the catapult arm was pulled back and released, the twisted rope uncoiled forcing the arm forward and releasing the projectile.
Early use of technology
Geometry, physics, statistics, mechanics and pneumatics were used to design the catapults. And designers conducted experiments to optimise their construction.
Maths was involved as each part of the catapult was proportional to the size of the object it was designed to propel. For example, the weight and length of the projectile was proportional to the size of the torsion springs.
Maths and geometry were also used to create tables of the correct proportions for parts of the catapult. These tables were used as reference guides so engineers could read off the specifications and save construction time.
People who designed catapults were well paid and given prizes for their work. They were also internationally recognised and met colleagues in neighbouring countries.
One soldier, who was known for his technical expertise, had his grave marked with a catapult.