Getting water up the bank
Rivers such as the Nile, the Tigris and the Euphrates flooded seasonally and watered fields along their banks. But farmers who wanted to irrigate land above the flood line, or to keep crops growing after the water fell, had a different problem: the water was lower than the fields. Lifting it by hand in jars was exhausting. Much of the history of irrigation machinery is about reducing that labor.
The simplest and best known solution is the shaduf.
How a shaduf works
A shaduf is a lever. A long wooden pole is balanced on a pivot, usually mounted on a frame or post of wood, mud brick or stone. At one end of the pole hangs a rope with a bucket or a leather or reed container. At the other end is a counterweight, often a lump of clay or a stone. The operator pulls the rope down to dip the bucket in the water. The counterweight then does much of the work of raising the full bucket, which is swung around and emptied into a ditch or basin higher up.
The advantage is that the person lifts only a part of the load, and the rest is balanced by the weight. A skilled worker could keep up a steady rhythm for hours. The lift from one shaduf is usually modest, often described as a meter or two, which suited riverbanks of that height. Where a greater lift was needed, several shadufs were set up in sequence, each lifting water to a channel from which the next took it.
Where and when
The shaduf is very old. Images of lever-lifting devices appear on cylinder seals from Mesopotamia that are often dated to around the late third millennium BCE, and the device is generally associated with that region first. It appears in Egyptian tomb paintings from the New Kingdom, roughly the middle of the second millennium BCE, and it is often described as arriving in Egypt around that time. Dating relies on art and surviving texts, so the details are not precise, and it is safest to say that it was in use by the second millennium BCE in both areas.
The name comes from Arabic, and similar devices have been used across a large area, including India, where the same idea is known by other names, and in China, where a related well sweep was common. Because it uses nothing but wood, rope and a weight, it could be built almost anywhere. Shadufs remained in use in parts of Egypt and elsewhere well into the twentieth century.
Other lifting devices
The shaduf was not the only option. Different devices suited different depths, labor and water supplies.
- The sakia. Also called a Persian wheel in some sources, it is a wheel with pots or buckets, turned by gearing and driven by an ox or other animal walking in a circle. It lifts water continuously and was widespread in Egypt and the Middle East from around the Hellenistic period. Gears of wood made it possible to turn the motion of the animal into the motion of the wheel.
- The noria. A large wheel set in a flowing river, with pots or paddles on its rim, turned by the current itself. The current fills the pots at the bottom and empties them at the top into a channel. The principle is shared with water mills, and norias are still preserved at Hama in Syria. Each of these devices relied on the wheel and axle.
- The Archimedes screw. A screw-shaped surface inside a tilted tube. Turned by hand or by animals, it lifts water upward as it rotates. It is traditionally associated with Archimedes of Syracuse in the third century BCE, though some scholars suggest similar devices may have been used earlier in Mesopotamia, and the question of its origin is not settled.
- Chain and bucket lifts. Continuous chains of buckets or square-pallet pumps, turned by treadmills or people stepping on a wheel, were known in China and in the Roman world. Roman engineers also used force pumps for mining and fire fighting.
Which device a farmer used depended on the height of the lift, the labor available and the water supply. A shaduf needed human strength, a sakia needed draft animals, and a noria needed a steady current.
Rope and wood
These machines depended on basic materials. Rope making was essential, since ropes had to be strong when wet, and leather and woven reed buckets were made from local materials. Wood was scarce in the Nile valley, so builders often used palm trunks, acacia and imported timber, and the supply of wood limited how many machines could be built.
Social and economic importance
Shadufs and their relatives let farmers cultivate more land and extend the growing season. In the Nile valley, they were used alongside basin irrigation, in which floodwater was captured in earth-banked fields and allowed to soak in. By lifting water to higher ground, a farm family could grow vegetables and other crops through the dry months. Historians generally consider them an important part of the toolkit that supported ancient farming states, though the share of the harvest that came from lifted water, as opposed to flooding, is hard to estimate.
Water lifting was also tied to labor and social structure. A shaduf could be worked by one or two people, so it suited small plots. Larger machines needed shared investment and sometimes a landowner’s control of animals or channels. Questions about who owned the machinery and who benefited are visible in later laws and records from the region.
From levers to engines
The next major change was mechanical power. Windmills for pumping, and then steam and electric pumps, replaced the earlier devices in many places. The history of pumping windmills and steam engines continues the same story of replacing muscle with power. Yet the older devices did not vanish at once. In some areas, shadufs and sakias were used into the twentieth century, and the lever principle still appears in simple well-sweeps and in teaching exhibits. The shaduf is a good example of an ancient tool whose design was good enough that it lasted for thousands of years with very little change.