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
Archimedes Palimpsest of the Walters Art Museum exhibit "Lost and Found: The Secrets of Archimedes". In 2015, in an experiment into the preservation of digital data, Swiss scientists encoded text from the Archimedes Palimpsest into DNA. Thanks to its deciphering, some mathematicians suggest, it is possible that Archimedes may have invented integration. It contains: The most remarkable of the above works is "The Method", of which the palimpsest contains the only known copy. In his other works, Archimedes often proves the equality of two areas or volumes with Eudoxus' method of exhaustion, an ancient Greek counterpart of the modern method of limits.