Archimedes' screw the outer casing to turn the entire apparatus as one piece, which would require that the casing be rigidly attached to the screw. Some researchers have postulated this as being the device used to irrigate the Hanging Gardens of Babylon, one of the Seven Wonders of the Ancient World. A cuneiform inscription of Assyrian King Sennacherib (704–681 BC) has been interpreted by Stephanie Dalley to describe casting water screws in bronze some 350 years earlier. This is consistent with classical author Strabo, who describes the Hanging Gardens as irrigated by screws. German engineer Konrad Kyeser equipped the Archimedes screw with
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