Answer:
The Archimedes Screw, which is used for "pumping" water.
The Archimedes Principle, which basically states that an object immersed in water, is buoyed up by a force equal to the weight of the fluid displaced by the object.
He also described the principles of using a lever for lifting objects and remarked: "Give me a place to stand on, and I will move the Earth."
He may have destroyed enemy ships by using a "heat ray" from concentrated sunlight
He also made a lot of work in mathematics.