The shaduf consists of an upright frame on which is suspended a long pole or branch, at a distance of about one-fifth of its length from one end. At the long end of this pole hangs a bucket, skin bag, or bitumen-coated reed basket, while the short end carries a weight (clay, stone, or similar) which serves as the counterpoise of a lever. When correctly balanced, the counterweight will support a half-filled bucket, so some effort is used to pull an empty bucket down to the water, but only the same effort is needed to lift a full bucket.
With an almost effortless swinging and lifting motion, the waterproof vessel is used to scoop up and carry water from one body of water (typically, a river or pond) to another. At the end of each movement, the water is emptied out into runnels that convey the water along irrigation ditches in the required direction.
We decided to build our shaduf out of k'nex using the design for making a lever. It worked really well except for swiveling from left to right. But it gave the kids a good idea of how the Egyptians got water from the Nile River to irrigate their crops. Jacob wasn't interested in helping at first, but once we get the water out, he joined in.
Tying the "bucket" onto the shaduf
Seeing how it works. You can see Jacob is getting interested.
Scooping up the water
Scooping more water. Jacob decided it was pretty cool after all.
2 comments:
That was just plain awesome. And yes I saw Jacob peaking around the corner.... trying his best to ignore, but he couldn't help himself.
Nice project. Great teacher. :)
OMG! Great job you guys!! I cannot say enough what an awesome teacher you are.
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