The Archimedes screw .

PART 1 The Archimedes screw is a simple mechanical device invented my Archimedes in the 3rd century. The device, often used to direct water into an irrigation channel, was composed of a wooden beam, several feet long, around which a spiral screw thread was built of layers of flexible, pitch-covered wood strips. Over this thread were fastened tight-fitting narrow planks running the length of the beam and giving it the appearance of a tube. By placing …

…crops as well as more of them. This would have helped the Romans and Egyptians in a way that they would be able to spend more time on other important issues as well as having more energy to use. The two main disadvantages of the screw are the lifts are limited upon the length you can build a given diameter screw and discharge from the screw is to the atmosphere and normally an open channel.