Scene showing a torsion powered arrow shooting catapult crewed by roman
soldiers and sheltered under a protective shed. This catapult , powered
by a twisted skein of rope, or horse
hair, is a cross between Archimedes spring
engine and a Roman mangonel or onager
The soldier standing at the top of frame is setting the missile, while
the rest of the crew draws down the arm. When released, the arm, complete
with fist, strikes the missile and sends it off on a ballistic path toward
the enemy.