 Zopyrus of Tarentum is mentioned twice, in a treatise on siege-engines by Biton (3rd or 2nd century BCE), as the inventor of an advanced form of the type of artillery known as the belly-bow (Marsden 1971, 74–77). Zopyrus’ bow used a winch to pull back the string and hence could shoot a six-foot wooden missile 4.5 inches thick (Marsden 1969, 14). It is not implausible to suppose that this is the same Zopyrus as is listed in Iamblichus’ catalogue of Pythagoreans under Tarentum (Diels 1965, 23), although Biton does not call him a Pythagorean. The traditional dating for Zopyrus puts him in the first half of the fourth century (Marsden 1971, 98, n. 52), but Kingsley has convincingly argued that he was in fact active in the last quarter of the fifth century, when he designed artillery for Cumae and Miletus (1995, 150 ff.). In a famous passage, Diodorus reports that in 399 BCE Dionysius I, the tyrant of Syracuse, gathered together skilled craftsmen from Italy, Greece and Carthage in order to construct artillery for his war with the Carthaginians (XIV 41.3). It seems not unlikely that Zopyrus was one of those who came from Italy. There is no reason to suppose, however, as Kingsley (1995, 146) and others do, that Zopyrus’ interest in mechanics was connected to his Pythagoreanism or that there was a specifically Pythagorean school of mechanics in Tarentum (Huffman 2005, 14–17).