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Imagine a tilted tube with its lower end in a river . Inside the tube , a spiral of metal or wood winds around a central pole . When someone turns the pole , water begins to climb out of the river . The answer is in the spiral . When the bottom end turns , it scoops up some water . That water settles into the lowest part of the spiral , a kind of pocket . As the pole keeps turning , the pocket moves up the tube , and the water stays inside it . Each turn carries the water a little higher , pocket by pocket . At the top , it spills out . The machine carries the name of Archimedes of Syracuse , a Greek thinker who lived in the 3rd century BC , in Sicily . Today that island belongs to Italy . Some writers say he invented the screw after a visit to Egypt , but this is only reported , not certain . Historians still disagree about whether he made it at all . What we can say is that people have used it for a very long time . A Roman writer named Vitruvius described a wooden one with eight blades . For centuries , people turned the screw by hand , with animals , or with windmills . During the Dutch Golden Age , windmills turned screws to drain land . Today motors do this work , and the machine has not disappeared . At Kinderdijk in the Netherlands , three screws drain low land into the Lek river . They do the work of 19 windmills from around 1740 , and those windmills still stand beside the pumps . Wastewater plants also use big screws , because they work well when the flow of water changes . Some screws even move live animals . Fish farms use them to lift fish out of their ponds without hurting them . An idea from more than 2,000 years ago still lifts water , and sometimes fish , today . 
