The Columbia Encyclopedia, Sixth Edition. 2001. shaduf

 or Shaduf (both: shdf´, shä´df) (KEY) , 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.

The Nile River cuts its way through the deserts of Egypt. During the yearly floods the rich black soil, or kemet, was left behind. The Egyptians used the fertile soil to grow their fields of wheat and barley. Once the floods receded and the fields dried, the plants would wither and die. The Egyptians solved this problem by digging canals. Water that poured into these canals flowed out the fields irrigating the land. A shaduf is an ancient water-raising device used by early Egyptians. It consists of a container made of animal skins or clay attached to a lever counterbalanced by stones. The container is dipped into the river, when full it is lifted out and dumped into a canal. It takes about twenty liters of water to irrigate one square meter of land for one day. How much water is required to irrigate a 500 square meter field? The shaduf by the museum can hold 20 liters of water. Using that information, how many times does it have to be worked to irrigate the field daily?

BEST DEFINITION