The 13 kg stone thrower could throw it’s projectile with a speed of 70 meters per second, that’s it, an energy of 32,000 joules. That would mean that if the speed was the same for larger and smaller projectiles a 80 kg stone projector would have the power of 200,000 joules (and not 100,000 joules as I previously) of energy. A small 6.6 kg stone projector would have 16,200 joules of power.
It was the first flamethrower in history and was first used by the Boeotians in the Peloponnesian war for the combustion of the Dilion walls. It consisted of a scooped out iron-bound beam (ripped at length and reconnected) that had a bellow at the user’s end and a cauldron hung with chains at the other end. A bent pipe from the airtight orifice of the beam went down into the cauldron which contained lit coal, sulphur and pitch (tar). With the operation of the bellow, enormous flames were created that burned the wooden walls and removed their defenders. Later it was used for the offence of stone fortifications causing cracks in the stones because of the high temperature and the parallel infusion of vinegar, urine or other erosive substances in them.
It was first used according to Stravon in Kabeira from the king of Pontos, Mithridatis VI
SOURCES: “Thucydides, Historiae, IV”