Screw pump different applications and handling fluids with varying characteristics. Each ‘screw pump' operates on the same basic principle of a screw turning to isolate a volume of fluid and convey it. However, the mechanical design of each is different. The primary difference is the number of screws: one, two, three or more. The screw pump was described by Archimedes on the occasion of his visit to Egypt. This suggests that the apparatus was unknown to the Greeks before Hellenistic times. A cuneiform inscription of Assyrian king Sennacherib (704–681 BC) has been interpreted by Stephanie Dalley to describe casting water screws in
Claw of Archimedes and implementing a design that was realistic, given what is known about Archimedes. Within seven days they were able to test their creation, and they did succeed in tipping over a model of a Roman ship so that it would sink. While this does not prove the existence of the Claw, it suggests that it would have been possible. 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,