What is an shaduf???

Ok what is an shuduf? Well it is an old of in my words acent water pump. It was like a stick and had a bucket on one end and a rock on the other to counter whate it bucket. So what there needs to be more than that. Well there is, there is an stand that holds the stick up it looks like this on the left. The Egyptuns used the shaduf whan there was a drie seasen. This helped them not have to break there backs just to get water b/c it is hard back breaking work to get water out of a river that is low.