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
Archimedes' screw granular materials such as plastic granules used in injection molding, and cereal grains. It may also be used to transport liquids. In industrial control applications the conveyor may be used as a rotary feeder or variable rate feeder to deliver a measured rate or quantity of material into a process. A variant of the Archimedes screw can also be found in some injection molding machines, die casting machines and extrusion of plastics, which employ a screw of decreasing pitch to compress and melt the material. It is also used in a rotary-screw air compressor. On a much larger scale, Archimedes's