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shaduf or shadoof (both: shədŏŏf´, shä´dŏŏf), primitive device used to lift water from a well or stream for irrigation purposes. Essentially the device consists of a long boom balanced across a horizontal support from 8 to 10 ft (2.4–3 m) above the ground. The beam has a long, thin end and a short, stubby end. From the long end a bucket or similar container is suspended, and on the shorter end there is a counterweight. The operator pulls on a rope that lowers the long end of the boom so that the bucket submerges and is filled with water. He then releases the rope, allowing the counterweight to raise the bucket to the desired level, and then empties the bucket and repeats the process. Shadufs can be used in a series where it is desired to raise water to a height exceeding the range of a single one. It has been suggested that the massive stones used in building the pyramids of Egypt were raised by an ancient variant of this device.