Claw of Archimedes Claw of Archimedes The Claw (, "harpágē", "snatcher") of Archimedes (also known as the "iron hand") was an ancient weapon devised by Archimedes to defend the seaward portion of Syracuse's city wall against amphibious assault. Although its exact nature is unclear, the accounts of ancient historians seem to describe it as a sort of crane equipped with a grappling hook that was able to lift an attacking ship partly out of the water, then either cause the ship to capsize or suddenly drop it. These machines featured prominently during the Second Punic War in 214 BC, when the Roman Republic
SS Archimedes fitted with Smith's patented propeller, "Princess Royal", was built in the north of England, and in 1842, several more screw-propelled vessels were built or launched in Britain, including "Bedlington", built at South Shields, "Bee", launched at Chatham, and the largest ship built to that date in Ireland, "Great Northern", launched at Derry. From this point, screw-propelled merchant ships grew rapidly in number. By the time the Cunard Line built the paddle steamer "Persia" for transatlantic service in 1856, the paddlewheel was already becoming an anachronism. Though Smith's "Archimedes" had played an important role in the introduction of screw propulsion, Smith