Wednesday, November 23, 2011

Overcoming Distance by Raising Elevation of Water AT the Source

Once a few humans figured out that gravity would move water, available at higher elevations to lower elevations (see post dated November 19, 2011), other humans began looking at ways to replace pack animals and human water-carriers who were transporting water from lower elevations to higher elevations.In other words, some humans began to address the problem of raising water to levels that would allow gravity to supply water to points far away from a water source. And invent they did.


Shaduf (~ 2000 B.C.)
Source - waterhisrory.org
The Shaduf was probably invented to replace the slow and laborious process of using slaves and pack animals to transport water to higher elevations.
The Shaduf employed the lever principle to raise water from a river or lake bed onto a higher landscape i.e. to feed an irrigation trench. 
A Shaduf could raise water a maximum of 7-8 feet.
The historical record shows Shaduf use in Mesopotamia and widespread use in Egypt.
The Shaduf came into existence about 2000 B.C.
A Shaduf requires human power and is limited by the size of its bucket but could be deployed in very large numbers to raise large quantities of water. There is extensive evidence of the Shaduf being mainly powered by slaves and convicts.
Archimedes Screw (~250 B.C.)
Source - school-for-champions.com
Attributed to be an invention by Archimedes, water was raised to higher elevations by turning the handle.
The compact design allowed this device to empty holds of ships, to draw away water from mines, keep areas free of water and, of course, draw water for irrigation and drinking purposes.
The Noria  or Water wheel (~250 B.C.)
Source - eo.wikipedia.org
A Noria is a wheel that raises water, a bucket at a time, to an elevation that is at most equal to the diameter of the wheel.
The buckets are each attached along the length of the wheel rim. 
To operate, the wheel is placed in a body of water with the bottom-most bucket submerged in the water body.
As the wheel turns, the lower-most bucket slips under water, is filled with water, rises up to the top of the wheel where it is emptied of water which flows into a channel that leads to a reservoir. Through this process, water in the  water body is raised to a height nearly equal to the diameter of the wheel.
Three different types of Noria exist depending upon how the wheel is turned. 
One design uses human or animal power, harnessed to the wheel, to turn the wheel.
In windy places, where the wind is especially strong, the Noria is modified such that the wind turns the wheel - this same rudimentary design is assumed to be replicated in a windmill designed for milling wheat and corn.
In streams where the water current is especially strong, the current pushes against appendages attached to the Noria that turn the wheel.
The city of Hama in Syria, has the largest known Noria (20 meters in diameter) in the world.
Elaborate Combinations (~90 A. D.)
Source - wikipedia.org
Recent excavations in mines in Spain and South Wales in the 1930s have revealed the existence of layers of waterwheels to excavate water from mines.





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